From 9ab4dbb25b30c5ee1bcc38f2ff1006a9eb094367 Mon Sep 17 00:00:00 2001
From: Alex Pott <alex.a.pott@googlemail.com>
Date: Fri, 30 Sep 2022 19:22:45 +0100
Subject: [PATCH] Issue #3312481 by mherchel, longwave: Update core's
 browserlist

(cherry picked from commit 98ccdcd7f72a681bb817cf72a343a2304c92f088)
---
 .../misc/dialog/off-canvas/css/dropbutton.css |  50 +---
 core/misc/dialog/off-canvas/css/form.css      |  32 +--
 core/misc/dialog/off-canvas/css/messages.css  |  29 +-
 core/misc/dialog/off-canvas/css/table.css     |  21 +-
 core/misc/dialog/off-canvas/css/tabledrag.css |  20 +-
 core/misc/dialog/off-canvas/css/throbber.css  |  22 +-
 core/misc/dialog/off-canvas/css/titlebar.css  |  20 +-
 core/misc/dialog/off-canvas/css/wrapper.css   |   7 +-
 .../layout_builder/css/layout-builder.css     |  20 +-
 .../modules/layout_builder/css/off-canvas.css |  11 +-
 .../workspaces/css/workspaces.off-canvas.css  |  40 +--
 .../workspaces/css/workspaces.toolbar.css     |  44 +---
 core/package.json                             |   3 +-
 core/themes/olivero/css/base/base.css         |  37 +--
 .../olivero/css/components/action-links.css   |  34 +--
 .../css/components/ajax-progress.module.css   |  61 +----
 .../autocomplete-loading.module.css           |   9 +-
 core/themes/olivero/css/components/block.css  |   3 +-
 core/themes/olivero/css/components/book.css   | 168 ++----------
 .../olivero/css/components/breadcrumb.css     | 167 +++---------
 core/themes/olivero/css/components/button.css |  80 ++----
 .../olivero/css/components/comments.css       | 248 ++++--------------
 .../components/container-inline.module.css    |   6 +-
 .../css/components/content-moderation.css     |  75 +-----
 .../themes/olivero/css/components/details.css |  66 +----
 .../olivero/css/components/dropbutton.css     |  56 +---
 .../olivero/css/components/embedded-media.css | 205 +++------------
 core/themes/olivero/css/components/feed.css   |   9 +-
 core/themes/olivero/css/components/field.css  |  29 +-
 .../olivero/css/components/fieldset.css       | 124 ++-------
 core/themes/olivero/css/components/footer.css |  28 +-
 .../olivero/css/components/form-boolean.css   |  12 +-
 .../olivero/css/components/form-select.css    |  39 +--
 .../olivero/css/components/form-text.css      |  24 +-
 core/themes/olivero/css/components/form.css   |  61 ++---
 .../css/components/header-buttons-mobile.css  |  17 +-
 .../css/components/header-navigation.css      |  99 ++-----
 .../css/components/header-search-narrow.css   | 129 ++-------
 .../css/components/header-search-wide.css     | 179 ++-----------
 .../css/components/header-site-branding.css   |  77 +-----
 .../css/components/header-sticky-toggle.css   |  38 +--
 core/themes/olivero/css/components/hero.css   |  12 +-
 core/themes/olivero/css/components/links.css  |  50 +---
 .../css/components/maintenance-page.css       |   3 +-
 .../olivero/css/components/messages.css       | 155 ++---------
 .../components/navigation/menu-sidebar.css    |  34 +--
 .../navigation/nav-button-mobile.css          |  84 +-----
 .../navigation/nav-primary-button.css         |  41 +--
 .../navigation/nav-primary-no-js.css          | 104 ++------
 .../navigation/nav-primary-wide.css           | 134 ++--------
 .../css/components/navigation/nav-primary.css | 204 +++-----------
 .../components/navigation/nav-secondary.css   |  87 ++----
 .../components/navigation/wide-nav-expand.css |  38 +--
 .../css/components/node-preview-container.css |  42 +--
 .../olivero/css/components/node-teaser.css    |  79 ++----
 core/themes/olivero/css/components/node.css   |  19 +-
 core/themes/olivero/css/components/pager.css  |  33 +--
 .../css/components/powered-by-block.css       |  11 +-
 .../olivero/css/components/progress.css       |   8 +-
 .../olivero/css/components/search-results.css |  64 ++---
 .../olivero/css/components/site-header.css    |   4 +-
 .../olivero/css/components/skip-link.css      |  21 +-
 core/themes/olivero/css/components/table.css  |  74 ++----
 .../olivero/css/components/tabledrag.css      |  29 +-
 core/themes/olivero/css/components/tabs.css   | 101 ++-----
 core/themes/olivero/css/components/tags.css   | 118 ++-------
 .../olivero/css/components/text-content.css   |  94 ++-----
 .../olivero/css/components/vertical-tabs.css  |  64 +----
 .../olivero/css/components/wide-image.css     |  61 +----
 .../layout/layout-builder-fourcol-section.css |  53 ++--
 .../layout-builder-threecol-section.css       |  28 +-
 .../layout/layout-builder-twocol-section.css  |  84 +-----
 .../css/layout/layout-content-narrow.css      |  62 +----
 .../layout-discovery-section-layout.css       |   6 +-
 .../olivero/css/layout/layout-footer.css      |  20 +-
 .../olivero/css/layout/layout-views-grid.css  |   4 +-
 core/themes/olivero/css/layout/layout.css     |  16 +-
 .../css/layout/region-content-below.css       |  42 +--
 .../olivero/css/layout/region-content.css     |   6 +-
 .../themes/olivero/css/layout/region-hero.css |   2 +-
 .../css/layout/region-secondary-menu.css      |   6 +-
 core/themes/olivero/css/layout/region.css     |   6 +-
 core/themes/olivero/css/layout/social-bar.css |  97 ++-----
 core/themes/olivero/css/layout/views.css      |   6 +-
 .../themes/olivero/css/theme/filter.theme.css |  33 +--
 core/yarn.lock                                |  13 +-
 86 files changed, 881 insertions(+), 3770 deletions(-)

diff --git a/core/misc/dialog/off-canvas/css/dropbutton.css b/core/misc/dialog/off-canvas/css/dropbutton.css
index 8dc8985ded2..a8b6d4a32ef 100644
--- a/core/misc/dialog/off-canvas/css/dropbutton.css
+++ b/core/misc/dialog/off-canvas/css/dropbutton.css
@@ -23,8 +23,7 @@
   --off-canvas-dropbutton-text-color-hover: var(--off-canvas-button-text-color-hover); /* Minimum 4.5:1 contrast ratio against --off-canvas-dropbutton-primary-background-color and --off-canvas-dropbutton-secondary-background-color. */
 }
 #drupal-off-canvas-wrapper .dropbutton-wrapper {
-    margin-top: var(--off-canvas-vertical-spacing-unit);
-    margin-bottom: var(--off-canvas-vertical-spacing-unit);
+    margin-block: var(--off-canvas-vertical-spacing-unit);
 
     /*
      * Styles for when the dropbutton is expanded.
@@ -46,12 +45,9 @@
 /*
     * Styles for single link variant of dropbutton.
     */
-[dir="ltr"] #drupal-off-canvas-wrapper .dropbutton-wrapper.dropbutton-single .dropbutton-widget {
-        padding-right: 0;
-}
-[dir="rtl"] #drupal-off-canvas-wrapper .dropbutton-wrapper.dropbutton-single .dropbutton-widget {
-        padding-left: 0;
-}
+#drupal-off-canvas-wrapper .dropbutton-wrapper.dropbutton-single .dropbutton-widget {
+        padding-inline-end: 0;
+      }
 #drupal-off-canvas-wrapper .dropbutton-wrapper.dropbutton-single .dropbutton-action:first-child {
           border-right: solid 1px var(--off-canvas-dropbutton-border-color); /* LTR */
           border-radius: var(--off-canvas-dropbutton-border-radius);
@@ -62,35 +58,19 @@
 #drupal-off-canvas-wrapper .dropbutton-wrapper.dropbutton-single .dropbutton-action a {
           justify-content: center;
         }
-[dir="ltr"] #drupal-off-canvas-wrapper .dropbutton-widget {
-    padding-right: var(--off-canvas-dropbutton-height);
-}
-[dir="rtl"] #drupal-off-canvas-wrapper .dropbutton-widget {
-    padding-left: var(--off-canvas-dropbutton-height);
-}
 #drupal-off-canvas-wrapper .dropbutton-widget {
     position: relative;
     width: max-content;
     max-width: 100%;
     height: var(--off-canvas-dropbutton-height);
+    padding-inline-end: var(--off-canvas-dropbutton-height);
     border-radius: var(--off-canvas-dropbutton-border-radius);
   }
-[dir="ltr"] #drupal-off-canvas-wrapper .dropbutton {
-    margin-left: 0;
-}
-[dir="rtl"] #drupal-off-canvas-wrapper .dropbutton {
-    margin-right: 0;
-}
-[dir="ltr"] #drupal-off-canvas-wrapper .dropbutton {
-    padding-left: 0;
-}
-[dir="rtl"] #drupal-off-canvas-wrapper .dropbutton {
-    padding-right: 0;
-}
 #drupal-off-canvas-wrapper .dropbutton {
     height: var(--off-canvas-dropbutton-height);
-    margin-top: 0;
-    margin-bottom: 0;
+    margin-block: 0;
+    margin-inline-start: 0;
+    padding-inline-start: 0;
     list-style: none;
     font-size: var(--off-canvas-dropbutton-font-size);
   }
@@ -99,12 +79,6 @@
     padding: 0;
     border: 0;
   }
-[dir="ltr"] #drupal-off-canvas-wrapper .dropbutton-toggle button {
-      right: 0;
-}
-[dir="rtl"] #drupal-off-canvas-wrapper .dropbutton-toggle button {
-      left: 0;
-}
 #drupal-off-canvas-wrapper .dropbutton-toggle button {
       position: absolute;
       top: 0;
@@ -118,6 +92,7 @@
       border-color: var(--off-canvas-dropbutton-border-color);
       border-radius: 0 var(--border-radius) var(--border-radius) 0; /* LTR */
       background: var(--off-canvas-dropbutton-primary-background-color);
+      inset-inline-end: 0;
     }
 #drupal-off-canvas-wrapper .dropbutton-toggle button:focus {
         outline: solid 2px var(--off-canvas-dropbutton-focus-outline-color);
@@ -136,13 +111,8 @@
         border-radius: var(--off-canvas-dropbutton-border-radius) 0 0 var(--off-canvas-dropbutton-border-radius);
       }
 /* This is the first <li> element in the list of actions. */
-[dir="ltr"] #drupal-off-canvas-wrapper .dropbutton-action:first-child {
-      margin-right: 2px;
-}
-[dir="rtl"] #drupal-off-canvas-wrapper .dropbutton-action:first-child {
-      margin-left: 2px;
-}
 #drupal-off-canvas-wrapper .dropbutton-action:first-child {
+      margin-inline-end: 2px;
       border: solid var(--off-canvas-dropbutton-border-width) var(--off-canvas-dropbutton-border-color);
       border-radius: var(--off-canvas-dropbutton-border-radius) 0 0 var(--off-canvas-dropbutton-border-radius); /* LTR */
       background: var(--off-canvas-dropbutton-primary-background-color);
diff --git a/core/misc/dialog/off-canvas/css/form.css b/core/misc/dialog/off-canvas/css/form.css
index 978aed3edff..c237f69ae5f 100644
--- a/core/misc/dialog/off-canvas/css/form.css
+++ b/core/misc/dialog/off-canvas/css/form.css
@@ -25,8 +25,7 @@
 }
 
 #drupal-off-canvas-wrapper form {
-    padding-top: var(--off-canvas-padding);
-    padding-bottom: var(--off-canvas-padding);
+    padding-block: var(--off-canvas-padding);
   }
 
 #drupal-off-canvas-wrapper form > *:first-child {
@@ -112,17 +111,10 @@
     appearance: none; /* Necessary for Safari. */
   }
 
-[dir="ltr"] #drupal-off-canvas-wrapper select {
-    padding-right: 1.25rem;
-}
-
-[dir="rtl"] #drupal-off-canvas-wrapper select {
-    padding-left: 1.25rem;
-}
-
 #drupal-off-canvas-wrapper select {
     -webkit-appearance: none;
     appearance: none;
+    padding-inline-end: 1.25rem;
     border: var(--drupal-off-canvas-input-border);
     border-radius: var(--drupal-off-canvas-input-border-radius);
     background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 14 9'%3e%3cpath fill='none' stroke-width='1.5' d='M1 1l6 6 6-6' stroke='%23545560'/%3e%3c/svg%3e");
@@ -137,17 +129,10 @@
 
 @media (forced-colors: active) {
 
-[dir="ltr"] #drupal-off-canvas-wrapper select {
-      padding-right: 0;
-  }
-
-[dir="rtl"] #drupal-off-canvas-wrapper select {
-      padding-left: 0;
-  }
-
 #drupal-off-canvas-wrapper select {
       -webkit-appearance: revert;
       appearance: revert;
+      padding-inline-end: 0;
       background: revert;
   }
     }
@@ -156,15 +141,8 @@
    * Autocomplete.
    */
 
-[dir="ltr"] #drupal-off-canvas-wrapper .form-autocomplete {
-    padding-right: 2.5rem;
-}
-
-[dir="rtl"] #drupal-off-canvas-wrapper .form-autocomplete {
-    padding-left: 2.5rem;
-}
-
-#drupal-off-canvas-wrapper .form-autocomplete { /* Room for icon. */
+#drupal-off-canvas-wrapper .form-autocomplete {
+    padding-inline-end: 2.5rem; /* Room for icon. */
     background-image: url("data:image/svg+xml,%3csvg width='40' height='20' viewBox='0 0 20 20' xmlns='http://www.w3.org/2000/svg'%3e%3cpath d='M8 1C3.46.827-.188 5.787 1.313 10.068c1.176 4.384 6.993 6.417 10.637 3.7.326-.39.565.276.846.442l3.74 3.739 1.413-1.414-4.35-4.35c2.811-3.468 1.15-9.247-3.062-10.71A7.003 7.003 0 008 1zm0 2c3.242-.123 5.849 3.42 4.777 6.477-.842 3.132-4.994 4.58-7.6 2.65-2.745-1.73-2.9-6.125-.285-8.044A5.006 5.006 0 018 3z' fill='%23868686'/%3e%3c/svg%3e");
     background-repeat: no-repeat;
     background-position: center right 1px; /* LTR */
diff --git a/core/misc/dialog/off-canvas/css/messages.css b/core/misc/dialog/off-canvas/css/messages.css
index 4ca82482760..f8424752b28 100644
--- a/core/misc/dialog/off-canvas/css/messages.css
+++ b/core/misc/dialog/off-canvas/css/messages.css
@@ -23,32 +23,17 @@
   --off-canvas-messages-icon-error: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' fill='%23e32700'%3e%3cpath d='M8.002 1c-3.868 0-7.002 3.134-7.002 7s3.134 7 7.002 7c3.865 0 7-3.134 7-7s-3.135-7-7-7zm4.025 9.284c.062.063.1.149.1.239 0 .091-.037.177-.1.24l-1.262 1.262c-.064.062-.15.1-.24.1s-.176-.036-.24-.1l-2.283-2.283-2.286 2.283c-.064.062-.15.1-.24.1s-.176-.036-.24-.1l-1.261-1.262c-.063-.062-.1-.148-.1-.24 0-.088.036-.176.1-.238l2.283-2.285-2.283-2.284c-.063-.064-.1-.15-.1-.24s.036-.176.1-.24l1.262-1.262c.063-.063.149-.1.24-.1.089 0 .176.036.24.1l2.285 2.284 2.283-2.284c.064-.063.15-.1.24-.1s.176.036.24.1l1.262 1.262c.062.063.1.149.1.24 0 .089-.037.176-.1.24l-2.283 2.284 2.283 2.284z'/%3e%3c/svg%3e");
 }
 
-[dir="ltr"] #drupal-off-canvas-wrapper .messages {
-    padding-left: calc(2 * var(--off-canvas-messages-icon-size));
-}
-
-[dir="rtl"] #drupal-off-canvas-wrapper .messages {
-    padding-right: calc(2 * var(--off-canvas-messages-icon-size));
-}
-
 #drupal-off-canvas-wrapper .messages {
     position: relative; /* Anchor :before pseudo-element. */
     margin-top: calc(2 * var(--off-canvas-vertical-spacing-unit));
-    padding: calc(2 * var(--off-canvas-vertical-spacing-unit)); /* Room for icon. */
+    padding: calc(2 * var(--off-canvas-vertical-spacing-unit));
+    padding-inline-start: calc(2 * var(--off-canvas-messages-icon-size)); /* Room for icon. */
     border: solid 1px transparent;
     background-color: var(--off-canvas-messages-background-color);
 
     /* Icon. */
   }
 
-[dir="ltr"] #drupal-off-canvas-wrapper .messages:before {
-      left: 0.625rem;
-}
-
-[dir="rtl"] #drupal-off-canvas-wrapper .messages:before {
-      right: 0.625rem;
-}
-
 #drupal-off-canvas-wrapper .messages:before {
       position: absolute;
       top: 50%;
@@ -59,6 +44,7 @@
       transform: translateY(-50%);
       background-repeat: no-repeat;
       background-size: contain;
+      inset-inline-start: 0.625rem;
     }
 
 @media (forced-colors: active) {
@@ -86,16 +72,9 @@
     display: none;
   }
 
-[dir="ltr"] #drupal-off-canvas-wrapper .messages__list {
-    padding-left: 1.25rem;
-}
-
-[dir="rtl"] #drupal-off-canvas-wrapper .messages__list {
-    padding-right: 1.25rem;
-}
-
 #drupal-off-canvas-wrapper .messages__list {
     margin: 0;
+    padding-inline-start: 1.25rem;
   }
 
 #drupal-off-canvas-wrapper .messages abbr {
diff --git a/core/misc/dialog/off-canvas/css/table.css b/core/misc/dialog/off-canvas/css/table.css
index eb20a081bc6..156b7fb64de 100644
--- a/core/misc/dialog/off-canvas/css/table.css
+++ b/core/misc/dialog/off-canvas/css/table.css
@@ -26,29 +26,16 @@
     border-bottom: 1px solid var(--off-canvas-border-color);
   }
 
-[dir="ltr"] #drupal-off-canvas-wrapper td,[dir="ltr"] 
-  #drupal-off-canvas-wrapper th {
-    text-align: left;
-}
-
-[dir="rtl"] #drupal-off-canvas-wrapper td,[dir="rtl"] 
-  #drupal-off-canvas-wrapper th {
-    text-align: right;
-}
-
 #drupal-off-canvas-wrapper td,
   #drupal-off-canvas-wrapper th {
     padding: var(--off-canvas-table-cell-padding);
+    text-align: start;
     vertical-align: middle;
   }
 
-[dir="ltr"] #drupal-off-canvas-wrapper td:first-child,[dir="ltr"]  #drupal-off-canvas-wrapper th:first-child {
-      padding-left: var(--off-canvas-first-cell-padding-start);
-}
-
-[dir="rtl"] #drupal-off-canvas-wrapper td:first-child,[dir="rtl"]  #drupal-off-canvas-wrapper th:first-child {
-      padding-right: var(--off-canvas-first-cell-padding-start);
-}
+#drupal-off-canvas-wrapper td:first-child, #drupal-off-canvas-wrapper th:first-child {
+      padding-inline-start: var(--off-canvas-first-cell-padding-start);
+    }
 
 #drupal-off-canvas-wrapper td:not(:last-child) td, #drupal-off-canvas-wrapper th:not(:last-child) td {
       border-bottom: solid 1px var(--off-canvas-border-color);
diff --git a/core/misc/dialog/off-canvas/css/tabledrag.css b/core/misc/dialog/off-canvas/css/tabledrag.css
index f1689205241..09038d3b40a 100644
--- a/core/misc/dialog/off-canvas/css/tabledrag.css
+++ b/core/misc/dialog/off-canvas/css/tabledrag.css
@@ -44,17 +44,8 @@
       gap: var(--off-canvas-table-cell-padding);
     }
 
-[dir="ltr"] #drupal-off-canvas-wrapper td abbr {
-      margin-left: 0;
-      margin-right: 0.3125rem;
-}
-
-[dir="rtl"] #drupal-off-canvas-wrapper td abbr {
-      margin-right: 0;
-      margin-left: 0.3125rem;
-}
-
 #drupal-off-canvas-wrapper td abbr {
+      margin-inline: 0 0.3125rem;
       text-decoration: none;
     }
 
@@ -100,16 +91,9 @@
     font-size: 0.875rem;
   }
 
-[dir="ltr"] #drupal-off-canvas-wrapper .tabledrag-toggle-weight-wrapper {
-    text-align: right;
-}
-
-[dir="rtl"] #drupal-off-canvas-wrapper .tabledrag-toggle-weight-wrapper {
-    text-align: left;
-}
-
 #drupal-off-canvas-wrapper .tabledrag-toggle-weight-wrapper {
     padding-top: 0.625rem;
+    text-align: end;
   }
 
 #drupal-off-canvas-wrapper .indentation {
diff --git a/core/misc/dialog/off-canvas/css/throbber.css b/core/misc/dialog/off-canvas/css/throbber.css
index 1f0c9012c4f..7bb67d3d8f3 100644
--- a/core/misc/dialog/off-canvas/css/throbber.css
+++ b/core/misc/dialog/off-canvas/css/throbber.css
@@ -34,29 +34,15 @@
   }
     }
 
-[dir="ltr"] #drupal-off-canvas-wrapper .layout-selection .ajax-progress,[dir="ltr"] 
-    #drupal-off-canvas-wrapper .inline-block-list .ajax-progress,[dir="ltr"] 
-    #drupal-off-canvas-wrapper .layout-selection .ajax-progress-throbber,[dir="ltr"] 
-    #drupal-off-canvas-wrapper .inline-block-list .ajax-progress-throbber {
-      right: 0;
-}
-
-[dir="rtl"] #drupal-off-canvas-wrapper .layout-selection .ajax-progress,[dir="rtl"] 
-    #drupal-off-canvas-wrapper .inline-block-list .ajax-progress,[dir="rtl"] 
-    #drupal-off-canvas-wrapper .layout-selection .ajax-progress-throbber,[dir="rtl"] 
-    #drupal-off-canvas-wrapper .inline-block-list .ajax-progress-throbber {
-      left: 0;
-}
-
 #drupal-off-canvas-wrapper .layout-selection .ajax-progress,
     #drupal-off-canvas-wrapper .inline-block-list .ajax-progress,
     #drupal-off-canvas-wrapper .layout-selection .ajax-progress-throbber,
     #drupal-off-canvas-wrapper .inline-block-list .ajax-progress-throbber {
       position: absolute;
-      top: 0;
-      bottom: 0;
-      margin-top: auto;
-      margin-bottom: auto;
+      inset-block-start: 0;
+      inset-block-end: 0;
+      inset-inline-end: 0;
+      margin-block: auto;
     }
 
 @keyframes off-canvas-throbber-spin {
diff --git a/core/misc/dialog/off-canvas/css/titlebar.css b/core/misc/dialog/off-canvas/css/titlebar.css
index 9b0d1701a40..f5f4308ca74 100644
--- a/core/misc/dialog/off-canvas/css/titlebar.css
+++ b/core/misc/dialog/off-canvas/css/titlebar.css
@@ -32,17 +32,10 @@
     /* The pencil icon. */
   }
 
-[dir="ltr"] #drupal-off-canvas-wrapper .ui-dialog-titlebar:before {
-      left: 1em;
-}
-
-[dir="rtl"] #drupal-off-canvas-wrapper .ui-dialog-titlebar:before {
-      right: 1em;
-}
-
 #drupal-off-canvas-wrapper .ui-dialog-titlebar:before {
       position: absolute;
       top: 0;
+      inset-inline-start: 1em;
       display: block;
       width: 1.25rem;
       height: 100%;
@@ -67,19 +60,10 @@
 
 /* Close button. */
 
-[dir="ltr"] #drupal-off-canvas-wrapper .ui-dialog-titlebar-close {
-    left: auto;
-    right: 0.625rem;
-}
-
-[dir="rtl"] #drupal-off-canvas-wrapper .ui-dialog-titlebar-close {
-    right: auto;
-    left: 0.625rem;
-}
-
 #drupal-off-canvas-wrapper .ui-dialog-titlebar-close {
     position: absolute;
     top: 50%;
+    inset-inline: auto 0.625rem;
     overflow: hidden;
     width: 1.875rem;
     height: 1.875rem;
diff --git a/core/misc/dialog/off-canvas/css/wrapper.css b/core/misc/dialog/off-canvas/css/wrapper.css
index f4bc192cf06..92296c72f9f 100644
--- a/core/misc/dialog/off-canvas/css/wrapper.css
+++ b/core/misc/dialog/off-canvas/css/wrapper.css
@@ -10,12 +10,6 @@
  *
  * @internal
  */
-[dir="ltr"] #drupal-off-canvas-wrapper {
-  border-left: solid var(--off-canvas-wrapper-border-width) var(--off-canvas-wrapper-border-color);
-}
-[dir="rtl"] #drupal-off-canvas-wrapper {
-  border-right: solid var(--off-canvas-wrapper-border-width) var(--off-canvas-wrapper-border-color);
-}
 #drupal-off-canvas-wrapper {
   --off-canvas-wrapper-box-shadow: 0 0 0.25rem 2px rgba(0, 0, 0, 0.3);
   --off-canvas-wrapper-border-color: #2d2d2d;
@@ -25,6 +19,7 @@
   overflow: auto;
   box-sizing: border-box;
   height: 100%;
+  border-inline-start: solid var(--off-canvas-wrapper-border-width) var(--off-canvas-wrapper-border-color);
   box-shadow: var(--off-canvas-wrapper-box-shadow);
 
   /*
diff --git a/core/modules/layout_builder/css/layout-builder.css b/core/modules/layout_builder/css/layout-builder.css
index 0bed71764e3..184669f2884 100644
--- a/core/modules/layout_builder/css/layout-builder.css
+++ b/core/modules/layout_builder/css/layout-builder.css
@@ -25,15 +25,8 @@
   background-color: #f7f7f7;
 }
 
-[dir="ltr"] .layout-builder__link--add {
-  padding-left: 1.3em;
-}
-
-[dir="rtl"] .layout-builder__link--add {
-  padding-right: 1.3em;
-}
-
 .layout-builder__link--add {
+  padding-inline-start: 1.3em;
   color: #686868;
   border-bottom: none;
   background: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' width='16px' height='16px'%3e%3cpath fill='%23787878' d='M0.656,9.023c0,0.274,0.224,0.5,0.499,0.5l4.853,0.001c0.274-0.001,0.501,0.226,0.5,0.5l0.001,4.853 c-0.001,0.273,0.227,0.5,0.501,0.5l1.995-0.009c0.273-0.003,0.497-0.229,0.5-0.503l0.002-4.806c0-0.272,0.228-0.5,0.499-0.502 l4.831-0.021c0.271-0.005,0.497-0.23,0.501-0.502l0.008-1.998c0-0.276-0.225-0.5-0.499-0.5l-4.852,0c-0.275,0-0.502-0.228-0.501-0.5 L9.493,1.184c0-0.275-0.225-0.499-0.5-0.499L6.997,0.693C6.722,0.694,6.496,0.92,6.495,1.195L6.476,6.026 c-0.001,0.274-0.227,0.5-0.501,0.5L1.167,6.525C0.892,6.526,0.665,6.752,0.665,7.026L0.656,9.023z'/%3e%3c/svg%3e") transparent center left / 1em no-repeat; /* LTR */
@@ -75,16 +68,6 @@
   background-color: #eff6fc;
 }
 
-[dir="ltr"] .layout-builder__link--remove {
-  margin-left: -0.625rem;
-  margin-right: 0.375rem;
-}
-
-[dir="rtl"] .layout-builder__link--remove {
-  margin-right: -0.625rem;
-  margin-left: 0.375rem;
-}
-
 .layout-builder__link--remove {
   position: relative;
   z-index: 2;
@@ -92,6 +75,7 @@
   box-sizing: border-box;
   width: 1.625rem;
   height: 1.625rem;
+  margin-inline: -0.625rem 0.375rem;
   padding: 0;
   white-space: nowrap;
   text-indent: -624.9375rem;
diff --git a/core/modules/layout_builder/css/off-canvas.css b/core/modules/layout_builder/css/off-canvas.css
index 950a8623e4f..5a6419bd6d1 100644
--- a/core/modules/layout_builder/css/off-canvas.css
+++ b/core/modules/layout_builder/css/off-canvas.css
@@ -53,20 +53,13 @@
   }
     }
 
-[dir="ltr"] #drupal-off-canvas-wrapper .inline-block-create-button {
-    padding-left: calc(2 * var(--off-canvas-padding) + var(--icon-size) / 2);
-}
-
-[dir="rtl"] #drupal-off-canvas-wrapper .inline-block-create-button {
-    padding-right: calc(2 * var(--off-canvas-padding) + var(--icon-size) / 2);
-}
-
 #drupal-off-canvas-wrapper .inline-block-create-button {
     --icon-size: 1rem;
 
     position: relative; /* Anchor pseudo-element. */
     display: block;
-    padding: 1.5rem; /* Room for icon */
+    padding: 1.5rem;
+    padding-inline-start: calc(2 * var(--off-canvas-padding) + var(--icon-size) / 2); /* Room for icon */
     border-bottom: 1px solid #333;
     font-size: 1rem;
 
diff --git a/core/modules/workspaces/css/workspaces.off-canvas.css b/core/modules/workspaces/css/workspaces.off-canvas.css
index 653cb4892ec..af07bd3eb78 100644
--- a/core/modules/workspaces/css/workspaces.off-canvas.css
+++ b/core/modules/workspaces/css/workspaces.off-canvas.css
@@ -41,16 +41,9 @@
       display: none;
     }
 
-[dir="ltr"] #drupal-off-canvas-wrapper.workspaces-dialog .ui-dialog-titlebar .ui-dialog-titlebar-close {
-      right: 1em;
-}
-
-[dir="rtl"] #drupal-off-canvas-wrapper.workspaces-dialog .ui-dialog-titlebar .ui-dialog-titlebar-close {
-      left: 1em;
-}
-
 #drupal-off-canvas-wrapper.workspaces-dialog .ui-dialog-titlebar .ui-dialog-titlebar-close {
-      top: 1em;
+      inset-block-start: 1em;
+      inset-inline-end: 1em;
       z-index: 1;
       transform: none;
     }
@@ -86,16 +79,9 @@
     line-height: 1.2;
   }
 
-[dir="ltr"] #drupal-off-canvas-wrapper.workspaces-dialog .active-workspace__label:before {
-      left: 0;
-}
-
-[dir="rtl"] #drupal-off-canvas-wrapper.workspaces-dialog .active-workspace__label:before {
-      right: 0;
-}
-
 #drupal-off-canvas-wrapper.workspaces-dialog .active-workspace__label:before {
       position: absolute;
+      inset-inline-start: 0;
       display: block;
       width: 1.25rem;
       height: 1.25rem;
@@ -174,19 +160,12 @@
 
 /* This is the link to the workspace. */
 
-[dir="ltr"] #drupal-off-canvas-wrapper.workspaces-dialog .workspaces__item {
-    padding-left: 3.125rem;
-}
-
-[dir="rtl"] #drupal-off-canvas-wrapper.workspaces-dialog .workspaces__item {
-    padding-right: 3.125rem;
-}
-
 #drupal-off-canvas-wrapper.workspaces-dialog .workspaces__item {
     position: relative;
     display: block;
     min-height: 4.6875rem;
-    padding-top: var(--off-canvas-padding);
+    padding-block-start: var(--off-canvas-padding);
+    padding-inline-start: 3.125rem;
     color: var(--off-canvas-text-color);
     outline-offset: -2px; /* Ensure focus outline doesn't overflow. */
     background-color: var(--off-canvas-background-color-light);
@@ -199,16 +178,9 @@
       background-color: #666;
     }
 
-[dir="ltr"] #drupal-off-canvas-wrapper.workspaces-dialog .workspaces__item:before {
-      left: var(--off-canvas-padding);
-}
-
-[dir="rtl"] #drupal-off-canvas-wrapper.workspaces-dialog .workspaces__item:before {
-      right: var(--off-canvas-padding);
-}
-
 #drupal-off-canvas-wrapper.workspaces-dialog .workspaces__item:before {
       position: absolute;
+      inset-inline-start: var(--off-canvas-padding);
       display: block;
       width: 1.25rem;
       height: 1.25rem;
diff --git a/core/modules/workspaces/css/workspaces.toolbar.css b/core/modules/workspaces/css/workspaces.toolbar.css
index e95d15876e1..32d50ddc3f3 100644
--- a/core/modules/workspaces/css/workspaces.toolbar.css
+++ b/core/modules/workspaces/css/workspaces.toolbar.css
@@ -21,36 +21,22 @@
   background-color: #81c071;
 }
 
-[dir="ltr"] .toolbar-oriented .toolbar-bar .workspaces-toolbar-tab {
-  float: right;
-}
-
-[dir="rtl"] .toolbar-oriented .toolbar-bar .workspaces-toolbar-tab {
-  float: left;
+.toolbar-oriented .toolbar-bar .workspaces-toolbar-tab {
+  float: inline-end;
 }
 
 @media (min-width: 16.5rem) {
-  [dir="ltr"] .toolbar:not(.toolbar-oriented) .toolbar-bar .workspaces-toolbar-tab {
-    float: right;
-  }
-  [dir="rtl"] .toolbar:not(.toolbar-oriented) .toolbar-bar .workspaces-toolbar-tab {
-    float: left;
+  .toolbar:not(.toolbar-oriented) .toolbar-bar .workspaces-toolbar-tab {
+    float: inline-end;
   }
 }
 
 /* Link within the toolbar tab. */
 
-[dir="ltr"] .toolbar .toolbar-bar .workspaces-toolbar-tab .toolbar-item {
-  text-align: left;
-}
-
-[dir="rtl"] .toolbar .toolbar-bar .workspaces-toolbar-tab .toolbar-item {
-  text-align: right;
-}
-
 .toolbar .toolbar-bar .workspaces-toolbar-tab .toolbar-item {
   width: 100%;
   margin: 0;
+  text-align: start;
   color: inherit;
 }
 
@@ -69,32 +55,16 @@
     max-width: 8em;
   }
 
-  [dir="ltr"] .toolbar .toolbar-bar .workspaces-toolbar-tab .toolbar-icon-workspace {
-    padding-left: 2.75em;
-    padding-right: 1.3333em;
-  }
-
-  [dir="rtl"] .toolbar .toolbar-bar .workspaces-toolbar-tab .toolbar-icon-workspace {
-    padding-right: 2.75em;
-    padding-left: 1.3333em;
-  }
-
   .toolbar .toolbar-bar .workspaces-toolbar-tab .toolbar-icon-workspace {
     overflow: hidden;
+    padding-inline: 2.75em 1.3333em;
     white-space: nowrap;
     text-indent: 0;
     text-overflow: ellipsis;
   }
 
-  [dir="ltr"] .toolbar .toolbar-bar .workspaces-toolbar-tab .toolbar-icon-workspace:before {
-    left: 0.6667em;
-  }
-
-  [dir="rtl"] .toolbar .toolbar-bar .workspaces-toolbar-tab .toolbar-icon-workspace:before {
-    right: 0.6667em;
-  }
-
   .toolbar .toolbar-bar .workspaces-toolbar-tab .toolbar-icon-workspace:before {
+    inset-inline-start: 0.6667em;
     width: 1.25rem;
     background-size: 100% auto;
   }
diff --git a/core/package.json b/core/package.json
index 4b457b2f99a..c14f58a08c1 100644
--- a/core/package.json
+++ b/core/package.json
@@ -109,5 +109,6 @@
     "last 1 ChromeAndroid version",
     "last 1 Samsung version",
     "Firefox ESR"
-  ]
+  ],
+  "dependencies": {}
 }
diff --git a/core/themes/olivero/css/base/base.css b/core/themes/olivero/css/base/base.css
index 67c53b7f8be..d893e313c86 100644
--- a/core/themes/olivero/css/base/base.css
+++ b/core/themes/olivero/css/base/base.css
@@ -146,8 +146,7 @@ h3,
 h4,
 h5,
 h6 {
-  margin-top: var(--sp);
-  margin-bottom: var(--sp);
+  margin-block: var(--sp);
   color: var(--color-text-neutral-loud);
   font-family: var(--font-sans);
   font-weight: bold;
@@ -161,38 +160,16 @@ h3,
 h4,
 h5,
 h6 {
-    margin-top: var(--sp2);
-    margin-bottom: var(--sp2);
+    margin-block: var(--sp2);
 }
   }
 
-[dir="ltr"] ul {
-  margin-left: 1.5em;
-}
-
-[dir="rtl"] ul {
-  margin-right: 1.5em;
-}
-
-[dir="ltr"] ul {
-  margin-right: 0;
-}
-
-[dir="rtl"] ul {
-  margin-left: 0;
-}
-
-[dir="ltr"] ul {
-  padding-left: 0;
-}
-
-[dir="rtl"] ul {
-  padding-right: 0;
-}
-
 ul {
-  margin-top: 0.25em;
-  margin-bottom: 0.25em;
+  margin-block-start: 0.25em;
+  margin-block-end: 0.25em;
+  margin-inline-start: 1.5em;
+  margin-inline-end: 0;
+  padding-inline-start: 0;
   list-style-type: disc;
   list-style-image: none;
 }
diff --git a/core/themes/olivero/css/components/action-links.css b/core/themes/olivero/css/components/action-links.css
index 57f05a15365..14165dd8e49 100644
--- a/core/themes/olivero/css/components/action-links.css
+++ b/core/themes/olivero/css/components/action-links.css
@@ -16,35 +16,13 @@
 /* Grid related breakpoints */
 /* Grid shifts from 6 to 14 columns. */
 /* Width of the entire grid maxes out. */
-[dir="ltr"] .action-links {
-  margin-left: 0;
-}
-[dir="rtl"] .action-links {
-  margin-right: 0;
-}
-[dir="ltr"] .action-links {
-  margin-right: 0;
-}
-[dir="rtl"] .action-links {
-  margin-left: 0;
-}
-[dir="ltr"] .action-links {
-  padding-left: 0;
-}
-[dir="rtl"] .action-links {
-  padding-right: 0;
-}
-[dir="ltr"] .action-links {
-  padding-right: 0;
-}
-[dir="rtl"] .action-links {
-  padding-left: 0;
-}
 .action-links {
-  margin-top: 0;
-  margin-bottom: 0;
-  padding-top: 0;
-  padding-bottom: 0;
+  margin-block: 0;
+  margin-inline-start: 0;
+  margin-inline-end: 0;
+  padding-block: 0;
+  padding-inline-start: 0;
+  padding-inline-end: 0;
   list-style: none;
 }
 .action-links li {
diff --git a/core/themes/olivero/css/components/ajax-progress.module.css b/core/themes/olivero/css/components/ajax-progress.module.css
index a0af93cb06f..fb566a9e290 100644
--- a/core/themes/olivero/css/components/ajax-progress.module.css
+++ b/core/themes/olivero/css/components/ajax-progress.module.css
@@ -31,29 +31,15 @@
  * Throbber.
  */
 
-[dir="ltr"] .ajax-progress-throbber {
-  margin-left: var(--sp0-5);
-}
-
-[dir="rtl"] .ajax-progress-throbber {
-  margin-right: var(--sp0-5);
-}
-
-[dir="ltr"] .ajax-progress-throbber {
-  margin-right: var(--sp0-5);
-}
-
-[dir="rtl"] .ajax-progress-throbber {
-  margin-left: var(--sp0-5);
-}
-
 .ajax-progress-throbber {
   position: relative;
   display: inline-flex;
   align-content: center;
   height: 1.125rem;
-  margin-top: -0.1875rem;
-  margin-bottom: 0;
+  margin-block-start: -0.1875rem;
+  margin-block-end: 0;
+  margin-inline-start: var(--sp0-5);
+  margin-inline-end: var(--sp0-5);
   vertical-align: middle;
   white-space: nowrap;
   line-height: 1.125rem;
@@ -66,16 +52,9 @@
   border-color: var(--color--primary-50) transparent var(--color--primary-50) var(--color--primary-50);
 }
 
-[dir="ltr"] .ajax-progress-throbber .message {
-  padding-left: var(--sp0-5);
-}
-
-[dir="rtl"] .ajax-progress-throbber .message {
-  padding-right: var(--sp0-5);
-}
-
 .ajax-progress-throbber .message {
   display: inline-block;
+  padding-inline-start: var(--sp0-5);
   font-size: var(--font-size-s);
   font-weight: 400;
 }
@@ -84,18 +63,11 @@
  * Full screen throbber.
  */
 
-[dir="ltr"] .ajax-progress-fullscreen {
-  left: 50%;
-}
-
-[dir="rtl"] .ajax-progress-fullscreen {
-  right: 50%;
-}
-
 .ajax-progress-fullscreen {
   position: fixed;
   z-index: 1000;
-  top: 50%;
+  inset-block-start: 50%;
+  inset-inline-start: 50%;
   width: 3.5rem;
   height: 3.5rem;
   margin: -1.75rem;
@@ -105,17 +77,10 @@
   box-shadow: 0 0.25rem 0.625rem rgba(34, 35, 48, 0.1); /* LTR */
 }
 
-[dir="ltr"] .ajax-progress-fullscreen:before {
-    left: 50%;
-}
-
-[dir="rtl"] .ajax-progress-fullscreen:before {
-    right: 50%;
-}
-
 .ajax-progress-fullscreen:before {
     position: absolute;
-    top: 50%;
+    inset-block-start: 50%;
+    inset-inline-start: 50%;
     width: 1.75rem;
     height: 1.75rem;
     margin: -0.875rem;
@@ -144,12 +109,8 @@
  * have a large margin set.
  */
 
-html[dir="ltr"].js .button:not(.js-hide) + .ajax-progress-throbber {
-  margin-left: 0;
-}
-
-html[dir="rtl"].js .button:not(.js-hide) + .ajax-progress-throbber {
-  margin-right: 0;
+html.js .button:not(.js-hide) + .ajax-progress-throbber {
+  margin-inline-start: 0;
 }
 
 @keyframes olivero-throbber {
diff --git a/core/themes/olivero/css/components/autocomplete-loading.module.css b/core/themes/olivero/css/components/autocomplete-loading.module.css
index a10bd91675c..75da64ce882 100644
--- a/core/themes/olivero/css/components/autocomplete-loading.module.css
+++ b/core/themes/olivero/css/components/autocomplete-loading.module.css
@@ -31,15 +31,8 @@
   --autocomplete-icon-right-offset: var(--sp1);
 }
 
-html[dir="ltr"].js .form-autocomplete {
-  padding-right: var(--sp3);
-}
-
-html[dir="rtl"].js .form-autocomplete {
-  padding-left: var(--sp3);
-}
-
 html.js .form-autocomplete {
+  padding-inline-end: var(--sp3);
   background-color: var(--color--white);
   background-image: var(--autocomplete-search-icon-url);
   background-repeat: no-repeat;
diff --git a/core/themes/olivero/css/components/block.css b/core/themes/olivero/css/components/block.css
index 51f9201362c..de2ab639f00 100644
--- a/core/themes/olivero/css/components/block.css
+++ b/core/themes/olivero/css/components/block.css
@@ -24,8 +24,7 @@
 /* Width of the entire grid maxes out. */
 
 .block__title {
-  margin-top: 0;
-  margin-bottom: var(--sp);
+  margin-block: 0 var(--sp);
   letter-spacing: 0.02em;
   color: var(--color-text-neutral-soft);
   font-size: var(--font-size-s);
diff --git a/core/themes/olivero/css/components/book.css b/core/themes/olivero/css/components/book.css
index 72851a72725..f14c811a2d7 100644
--- a/core/themes/olivero/css/components/book.css
+++ b/core/themes/olivero/css/components/book.css
@@ -23,46 +23,17 @@
 
 /* Width of the entire grid maxes out. */
 
-[dir="ltr"] .book-pager {
-  margin-left: 0;
-}
-
-[dir="rtl"] .book-pager {
-  margin-right: 0;
-}
-
-[dir="ltr"] .book-pager {
-  margin-right: 0;
-}
-
-[dir="rtl"] .book-pager {
-  margin-left: 0;
-}
-
-[dir="ltr"] .book-pager {
-  padding-left: 0;
-}
-
-[dir="rtl"] .book-pager {
-  padding-right: 0;
-}
-
-[dir="ltr"] .book-pager {
-  padding-right: 0;
-}
-
-[dir="rtl"] .book-pager {
-  padding-left: 0;
-}
-
 .book-pager {
   display: flex;
   flex-wrap: wrap;
-  margin-top: 0 var(--sp);
-  padding-top: 0;
-  padding-bottom: var(--sp);
+  margin-block-start: 0 var(--sp);
+  margin-inline-start: 0;
+  margin-inline-end: 0;
+  padding-block: 0 var(--sp);
+  padding-inline-start: 0;
+  padding-inline-end: 0;
   list-style: none;
-  border-bottom: solid 1px var(--color--primary-40);
+  border-block-end: solid 1px var(--color--primary-40);
 }
 
 .book-pager__item {
@@ -85,21 +56,10 @@
 
 @media (min-width: 31.25rem) {
 
-[dir="ltr"] .book-pager__item--next {
-    margin-left: auto;
-  }
-
-[dir="rtl"] .book-pager__item--next {
-    margin-right: auto;
-  }
-
-[dir="ltr"] .book-pager__item--next {
-    text-align: right;
-  }
-
-[dir="rtl"] .book-pager__item--next {
-    text-align: left;
-  }
+.book-pager__item--next {
+    margin-inline-start: auto;
+    text-align: end;
+}
   }
 
 .book-pager__link {
@@ -112,117 +72,43 @@
   font-weight: 600;
 }
 
-[dir="ltr"] .book-pager__link--previous:before {
-    margin-right: 0.25em;
-}
-
-[dir="rtl"] .book-pager__link--previous:before {
-    margin-left: 0.25em;
-}
-
-[dir="ltr"] .book-pager__link--previous:before {
-    border-left: solid 0.1875rem currentColor;
-}
-
-[dir="rtl"] .book-pager__link--previous:before {
-    border-right: solid 0.1875rem currentColor;
-}
-
 .book-pager__link--previous:before {
     display: block;
     width: var(--sp0-5);
     height: var(--sp0-5);
+    margin-inline-end: 0.25em;
     content: "";
     transform: rotate(-45deg);
-    border-top: solid 0.1875rem currentColor;
+    border-block-start: solid 0.1875rem currentColor;
+    border-inline-start: solid 0.1875rem currentColor;
   }
 
-[dir="ltr"] .book-pager__link--next:after {
-    margin-left: 0.25em;
-}
-
-[dir="rtl"] .book-pager__link--next:after {
-    margin-right: 0.25em;
-}
-
-[dir="ltr"] .book-pager__link--next:after {
-    border-left: solid 0.1875rem currentColor;
-}
-
-[dir="rtl"] .book-pager__link--next:after {
-    border-right: solid 0.1875rem currentColor;
-}
-
 .book-pager__link--next:after {
     display: block;
     width: var(--sp0-5);
     height: var(--sp0-5);
+    margin-inline-start: 0.25em;
     content: "";
     transform: rotate(135deg);
-    border-top: solid 0.1875rem currentColor;
+    border-block-start: solid 0.1875rem currentColor;
+    border-inline-start: solid 0.1875rem currentColor;
   }
 
-[dir="ltr"] .book-navigation__menu {
-  margin-left: 0;
-}
-
-[dir="rtl"] .book-navigation__menu {
-  margin-right: 0;
-}
-
-[dir="ltr"] .book-navigation__menu {
-  margin-right: 0;
-}
-
-[dir="rtl"] .book-navigation__menu {
-  margin-left: 0;
-}
-
-[dir="ltr"] .book-navigation__menu {
-  padding-left: 0;
-}
-
-[dir="rtl"] .book-navigation__menu {
-  padding-right: 0;
-}
-
-[dir="ltr"] .book-navigation__menu {
-  padding-right: 0;
-}
-
-[dir="rtl"] .book-navigation__menu {
-  padding-left: 0;
-}
-
 .book-navigation__menu {
-  margin-top: var(--sp2);
-  margin-bottom: var(--sp2);
-  padding-top: 0;
-  padding-bottom: 0;
+  margin-block: var(--sp2);
+  margin-inline-start: 0;
+  margin-inline-end: 0;
+  padding-block: 0;
+  padding-inline-start: 0;
+  padding-inline-end: 0;
   list-style: none;
 }
 
-[dir="ltr"] .book-navigation__item {
-  padding-left: 0;
-}
-
-[dir="rtl"] .book-navigation__item {
-  padding-right: 0;
-}
-
-[dir="ltr"] .book-navigation__item {
-  padding-right: 0;
-}
-
-[dir="rtl"] .book-navigation__item {
-  padding-left: 0;
-}
-
 .book-navigation__item {
-  margin-top: 0;
-  margin-bottom: 0;
-  padding-top: 0;
-  padding-bottom: 0;
+  margin-block: 0;
+  padding-block: 0;
+  padding-inline-start: 0;
+  padding-inline-end: 0;
   list-style: none;
 }
 
diff --git a/core/themes/olivero/css/components/breadcrumb.css b/core/themes/olivero/css/components/breadcrumb.css
index 4e6fe9b39dc..761156c871f 100644
--- a/core/themes/olivero/css/components/breadcrumb.css
+++ b/core/themes/olivero/css/components/breadcrumb.css
@@ -32,17 +32,10 @@
   /* Shadow on the right side of breadcrumbs for narrow screens. */
 }
 
-[dir="ltr"] .breadcrumb:after {
-    right: calc(var(--sp1) * -1);
-}
-
-[dir="rtl"] .breadcrumb:after {
-    left: calc(var(--sp1) * -1);
-}
-
 .breadcrumb:after {
     position: absolute;
-    top: 0;
+    inset-block-start: 0;
+    inset-inline-end: calc(var(--sp1) * -1);
     width: var(--sp3);
     height: var(--sp2);
     content: "";
@@ -67,122 +60,46 @@
   background: linear-gradient(to right, var(--color--white) 0%, rgba(255, 255, 255, 0) 100%);
 }
 
-[dir="ltr"] .breadcrumb__content {
-  margin-left: calc(var(--sp0-5) * -1);
-}
-
-[dir="rtl"] .breadcrumb__content {
-  margin-right: calc(var(--sp0-5) * -1);
-}
-
-[dir="ltr"] .breadcrumb__content {
-  margin-right: calc(var(--sp1) * -1);
-}
-
-[dir="rtl"] .breadcrumb__content {
-  margin-left: calc(var(--sp1) * -1);
-}
-
-[dir="ltr"] .breadcrumb__content {
-  padding-left: var(--sp0-5);
-}
-
-[dir="rtl"] .breadcrumb__content {
-  padding-right: var(--sp0-5);
-}
-
 .breadcrumb__content {
   overflow: auto;
-  margin-top: calc(var(--sp0-5) * -1);
-  margin-bottom: calc(var(--sp0-5) * -1);
-  padding-top: var(--sp0-5);
-  padding-bottom: var(--sp0-5);
+  margin-block-start: calc(var(--sp0-5) * -1);
+  margin-block-end: calc(var(--sp0-5) * -1);
+  margin-inline-start: calc(var(--sp0-5) * -1);
+  margin-inline-end: calc(var(--sp1) * -1);
+  padding-block-start: var(--sp0-5);
+  padding-block-end: var(--sp0-5);
+  padding-inline-start: var(--sp0-5);
   -webkit-overflow-scrolling: touch;
 }
 
 @media (min-width: 62.5rem) {
 
-[dir="ltr"] .breadcrumb__content {
-    margin-right: 0;
+.breadcrumb__content {
+    margin-inline-end: 0;
+}
   }
 
-[dir="rtl"] .breadcrumb__content {
-    margin-left: 0;
-  }
-  }
-
-[dir="ltr"] .breadcrumb__list {
-  margin-left: calc(var(--sp1) * -1);
-}
-
-[dir="rtl"] .breadcrumb__list {
-  margin-right: calc(var(--sp1) * -1);
-}
-
-[dir="ltr"] .breadcrumb__list {
-  margin-right: calc(var(--sp1) * -1);
-}
-
-[dir="rtl"] .breadcrumb__list {
-  margin-left: calc(var(--sp1) * -1);
-}
-
-[dir="ltr"] .breadcrumb__list {
-  padding-left: var(--sp1);
-}
-
-[dir="rtl"] .breadcrumb__list {
-  padding-right: var(--sp1);
-}
-
-[dir="ltr"] .breadcrumb__list {
-  padding-right: 0;
-}
-
-[dir="rtl"] .breadcrumb__list {
-  padding-left: 0;
-}
-
 .breadcrumb__list {
   overflow-x: auto;
   width: max-content;
-  margin-top: 0;
-  margin-bottom: 0;
-  padding-top: 0;
-  padding-bottom: var(--sp1);
+  margin-block: 0;
+  margin-inline-start: calc(var(--sp1) * -1);
+  margin-inline-end: calc(var(--sp1) * -1);
+  padding-block: 0 var(--sp1);
+  padding-inline-start: var(--sp1);
+  padding-inline-end: 0;
   list-style: none;
   white-space: nowrap;
 }
 
 @media (min-width: 62.5rem) {
 
-[dir="ltr"] .breadcrumb__list {
-    margin-left: 0;
-  }
-
-[dir="rtl"] .breadcrumb__list {
-    margin-right: 0;
-  }
-
-[dir="ltr"] .breadcrumb__list {
-    margin-right: 0;
-  }
-
-[dir="rtl"] .breadcrumb__list {
-    margin-left: 0;
-  }
-
-[dir="ltr"] .breadcrumb__list {
-    padding-left: 0;
-  }
-
-[dir="rtl"] .breadcrumb__list {
-    padding-right: 0;
-  }
-
 .breadcrumb__list {
     overflow: visible;
-    padding-bottom: 0;
+    margin-inline-start: 0;
+    margin-inline-end: 0;
+    padding-block-end: 0;
+    padding-inline-start: 0;
     white-space: normal;
 }
   }
@@ -191,49 +108,25 @@
   display: inline-block;
 }
 
-[dir="ltr"] .breadcrumb__item:nth-child(n+2):before {
-    margin-left: 1rem;
-    margin-right: 1.25rem;
-}
-
-[dir="rtl"] .breadcrumb__item:nth-child(n+2):before {
-    margin-right: 1rem;
-    margin-left: 1.25rem;
-}
-
-[dir="ltr"] .breadcrumb__item:nth-child(n+2):before {
-    border-right: 2px solid var(--color--gray-45);
-}
-
-[dir="rtl"] .breadcrumb__item:nth-child(n+2):before {
-    border-left: 2px solid var(--color--gray-45);
-}
-
 .breadcrumb__item:nth-child(n+2):before {
     display: inline-block;
     width: 0.5rem;
     height: 0.5rem;
+    margin-inline: 1rem 1.25rem;
     content: "";
     transform: rotate(45deg); /* LTR */
-    border-top: 2px solid var(--color--gray-45);
+    border-block-start: 2px solid var(--color--gray-45);
+    border-inline-end: 2px solid var(--color--gray-45);
   }
 
-[dir="ltr"] .breadcrumb__item:last-child {
-    margin-right: var(--sp3);
-}
-
-[dir="rtl"] .breadcrumb__item:last-child {
-    margin-left: var(--sp3);
-}
+.breadcrumb__item:last-child {
+    margin-inline-end: var(--sp3);
+  }
 
 @media (min-width: 62.5rem) {
 
-[dir="ltr"] .breadcrumb__item:last-child {
-      margin-right: 0;
-  }
-
-[dir="rtl"] .breadcrumb__item:last-child {
-      margin-left: 0;
+.breadcrumb__item:last-child {
+      margin-inline-end: 0;
   }
     }
 
diff --git a/core/themes/olivero/css/components/button.css b/core/themes/olivero/css/components/button.css
index 23f4d1f53fc..d9ed3702174 100644
--- a/core/themes/olivero/css/components/button.css
+++ b/core/themes/olivero/css/components/button.css
@@ -23,31 +23,14 @@
 
 /* Width of the entire grid maxes out. */
 
-[dir="ltr"] .button {
-  margin-left: 0;
-}
-
-[dir="rtl"] .button {
-  margin-right: 0;
-}
-
-[dir="ltr"] .button {
-  margin-right: var(--sp1);
-}
-
-[dir="rtl"] .button {
-  margin-left: var(--sp1);
-}
-
 .button {
   display: inline-block;
   height: var(--sp3);
-  margin-top: var(--sp1);
-  margin-bottom: var(--sp1);
-  padding-top: calc((var(--sp3) - var(--line-height-s)) / 2);
-  padding-bottom: calc((var(--sp3) - var(--line-height-s)) / 2);
-  padding-left: var(--sp1-5);
-  padding-right: var(--sp1-5);
+  margin-block: var(--sp1);
+  margin-inline-start: 0;
+  margin-inline-end: var(--sp1);
+  padding-block: calc((var(--sp3) - var(--line-height-s)) / 2);
+  padding-inline: var(--sp1-5);
   cursor: pointer;
   text-align: center;
   text-decoration: none;
@@ -101,43 +84,24 @@
     align-items: center;
 
     /* Top padding accounts for font not being vertically centered within line-height. */
-    padding-top: 1px;
-    padding-bottom: 0;
-    padding-left: var(--sp1-5);
-    padding-right: var(--sp1-5);
+    padding-block: 1px 0;
+    padding-inline: var(--sp1-5);
     line-height: var(--line-height-s);
 }
   }
 
 /* No margin if is part of a menu. */
 
-[dir="ltr"] .menu .button {
-  margin-left: 0;
-}
-
-[dir="rtl"] .menu .button {
-  margin-right: 0;
-}
-
-[dir="ltr"] .menu .button {
-  margin-right: 0;
-}
-
-[dir="rtl"] .menu .button {
-  margin-left: 0;
-}
-
 .menu .button {
-  margin-top: 0;
-  margin-bottom: 0;
+  margin-block: 0;
+  margin-inline-start: 0;
+  margin-inline-end: 0;
 }
 
 .button--small {
   height: var(--sp2-5);
-  padding-top: calc((var(--sp2-5) - var(--line-height-s)) / 2);
-  padding-bottom: calc((var(--sp2-5) - var(--line-height-s)) / 2);
-  padding-left: var(--sp);
-  padding-right: var(--sp);
+  padding-block: calc((var(--sp2-5) - var(--line-height-s)) / 2);
+  padding-inline: var(--sp);
   font-size: var(--font-size-base);
   line-height: normal;
 }
@@ -170,29 +134,15 @@
   align-items: center;
 }
 
-[dir="ltr"] .button--icon-back:before {
-    margin-right: 0.5em;
-}
-
-[dir="rtl"] .button--icon-back:before {
-    margin-left: 0.5em;
-}
-
-[dir="ltr"] .button--icon-back:before {
-    border-left: solid 2px currentColor;
-}
-
-[dir="rtl"] .button--icon-back:before {
-    border-right: solid 2px currentColor;
-}
-
 .button--icon-back:before {
     display: block;
     width: 0.5em;
     height: 0.5em;
+    margin-inline-end: 0.5em;
     content: "";
     transform: rotate(45deg); /* LTR */
-    border-bottom: solid 2px currentColor;
+    border-block-end: solid 2px currentColor;
+    border-inline-start: solid 2px currentColor;
   }
 
 [dir="rtl"] .button--icon-back:before {
diff --git a/core/themes/olivero/css/components/comments.css b/core/themes/olivero/css/components/comments.css
index 3f8ff293a96..d286e66e563 100644
--- a/core/themes/olivero/css/components/comments.css
+++ b/core/themes/olivero/css/components/comments.css
@@ -29,59 +29,30 @@
 }
 
 .comment--level-1 {
-  border-top: 2px solid var(--color--gray-95);
+  border-block-start: 2px solid var(--color--gray-95);
 }
 
 .comment--level-1 ~ .comment--level-1 {
-    margin-top: var(--sp2);
+    margin-block-start: var(--sp2);
   }
 
 .comments__title {
   display: flex;
   align-items: center;
-  margin-top: 0;
-}
-
-[dir="ltr"] .comments__count {
-  margin-left: var(--sp);
-}
-
-[dir="rtl"] .comments__count {
-  margin-right: var(--sp);
-}
-
-[dir="ltr"] .comments__count {
-  margin-right: var(--sp);
-}
-
-[dir="rtl"] .comments__count {
-  margin-left: var(--sp);
-}
-
-[dir="ltr"] .comments__count {
-  padding-left: 0.3125rem;
-}
-
-[dir="rtl"] .comments__count {
-  padding-right: 0.3125rem;
-}
-
-[dir="ltr"] .comments__count {
-  padding-right: 0.3125rem;
-}
-
-[dir="rtl"] .comments__count {
-  padding-left: 0.3125rem;
+  margin-block-start: 0;
 }
 
 .comments__count {
   position: relative;
   display: inline-block;
   min-width: 2.125rem;
-  margin-top: 0;
-  margin-bottom: var(--sp0-5);
-  padding-top: 0;
-  padding-bottom: 0;
+  margin-block-start: 0;
+  margin-block-end: var(--sp0-5);
+  margin-inline-start: var(--sp);
+  margin-inline-end: var(--sp);
+  padding-block: 0;
+  padding-inline-start: 0.3125rem;
+  padding-inline-end: 0.3125rem;
   text-align: center;
   color: var(--color--white);
   border-radius: 2px;
@@ -90,65 +61,36 @@
   line-height: 1.3125rem;
 }
 
-[dir="ltr"] .comments__count:after {
-    left: 0.5rem;
-}
-
-[dir="rtl"] .comments__count:after {
-    right: 0.5rem;
-}
-
-[dir="ltr"] .comments__count:after {
-    border-right: 0.5rem solid transparent;
-}
-
-[dir="rtl"] .comments__count:after {
-    border-left: 0.5rem solid transparent;
-}
-
 .comments__count:after {
     position: absolute;
-    bottom: -0.4375rem;
+    inset-block-end: -0.4375rem;
+    inset-inline-start: 0.5rem;
     width: 0;
     height: 0;
     content: "";
-    border-top: 0.4375rem solid var(--color--primary-40);
+    border-block-start: 0.4375rem solid var(--color--primary-40);
+    border-inline-end: 0.5rem solid transparent;
   }
 
 .comment-form {
-  padding-bottom: var(--sp2);
+  padding-block-end: var(--sp2);
 }
 
-[dir="ltr"] .add-comment__form {
-  padding-left: 0;
-}
-
-[dir="rtl"] .add-comment__form {
-  padding-right: 0;
-}
-
-[dir="ltr"] .comment {
-  padding-left: var(--sp3);
-}
-
-[dir="rtl"] .comment {
-  padding-right: var(--sp3);
+.add-comment__form {
+  padding-inline-start: 0;
 }
 
 .comment {
   position: relative;
-  padding-top: var(--sp2);
+  padding-block-start: var(--sp2);
+  padding-inline-start: var(--sp3);
 }
 
 @media (min-width: 43.75rem) {
 
-[dir="ltr"] .comment {
-    padding-left: 0;
-  }
-
-[dir="rtl"] .comment {
-    padding-right: 0;
-  }
+.comment {
+    padding-inline-start: 0;
+}
   }
 
 .comment__text-content {
@@ -163,12 +105,11 @@
 /* Override for .field:not(:last-child) */
 
 .comment__text-content:not(:last-child) {
-    margin-bottom: 0;
+    margin-block-end: 0;
   }
 
 .comment__links {
-  margin-top: var(--sp);
-  margin-bottom: 0;
+  margin-block: var(--sp) 0;
 }
 
 .comment__links-link {
@@ -183,22 +124,13 @@
   }
 
 .add-comment__picture-wrapper {
-  top: calc(var(--line-height-base) + var(--sp0-5));
-}
-
-[dir="ltr"] .add-comment__picture,[dir="ltr"] 
-.comment__picture {
-  left: 0;
-}
-
-[dir="rtl"] .add-comment__picture,[dir="rtl"] 
-.comment__picture {
-  right: 0;
+  inset-block-start: calc(var(--line-height-base) + var(--sp0-5));
 }
 
 .add-comment__picture,
 .comment__picture {
   position: absolute;
+  inset-inline-start: 0;
   overflow: hidden;
   width: var(--sp2);
   height: var(--sp2);
@@ -236,18 +168,9 @@
 
 @media (min-width: 43.75rem) {
 
-[dir="ltr"] .add-comment__picture,[dir="ltr"] 
-.comment__picture {
-    left: calc(-1 * var(--sp5));
-  }
-
-[dir="rtl"] .add-comment__picture,[dir="rtl"] 
-.comment__picture {
-    right: calc(-1 * var(--sp5));
-  }
-
 .add-comment__picture,
 .comment__picture {
+    inset-inline-start: calc(-1 * var(--sp5));
     width: var(--sp3);
     height: var(--sp3);
 }
@@ -255,15 +178,8 @@
 
 @media (min-width: 43.75rem) {
 
-[dir="ltr"] .indented .comment__picture {
-    left: calc(-1 * var(--sp4));
-  }
-
-[dir="rtl"] .indented .comment__picture {
-    right: calc(-1 * var(--sp4));
-  }
-
 .indented .comment__picture {
+    inset-inline-start: calc(-1 * var(--sp4));
     width: var(--sp2);
     height: var(--sp2);
 }
@@ -273,15 +189,8 @@
     display: inline;
   }
 
-[dir="ltr"] .comment__author {
-  margin-right: var(--sp);
-}
-
-[dir="rtl"] .comment__author {
-  margin-left: var(--sp);
-}
-
 .comment__author {
+  margin-inline-end: var(--sp);
   font-family: var(--font-sans);
   font-size: 1rem;
   font-weight: 700;
@@ -300,97 +209,42 @@
   line-height: var(--sp);
 }
 
-[dir="ltr"] .indented {
-  margin-left: var(--comment-indentation);
-}
-
-[dir="rtl"] .indented {
-  margin-right: var(--comment-indentation);
-}
-
-[dir="ltr"] .indented > .comment:not(:last-of-type, .has-children):before {
-    left: calc(-1 * var(--comment-indentation) - var(--sp));
-}
-
-[dir="rtl"] .indented > .comment:not(:last-of-type, .has-children):before {
-    right: calc(-1 * var(--comment-indentation) - var(--sp));
-}
-
-[dir="ltr"] .indented > .comment:not(:last-of-type, .has-children):before {
-    border-left: solid 1px var(--color--gray-95);
-}
-
-[dir="rtl"] .indented > .comment:not(:last-of-type, .has-children):before {
-    border-right: solid 1px var(--color--gray-95);
+.indented {
+  margin-inline-start: var(--comment-indentation);
 }
 
 .indented > .comment:not(:last-of-type, .has-children):before {
     position: absolute;
-    top: var(--sp2); /* Comment's padding-top */
+    inset-block-start: var(--sp2);
+    inset-inline-start: calc(-1 * var(--comment-indentation) - var(--sp)); /* Comment's padding-top */
     width: 0;
     height: 100%;
     content: "";
+    border-inline-start: solid 1px var(--color--gray-95);
   }
 
 @media (min-width: 43.75rem) {
 
-[dir="ltr"] .indented > .comment:not(:last-of-type, .has-children):before {
-      left: calc(-1 * var(--comment-indentation--md) + var(--sp));
-  }
-
-[dir="rtl"] .indented > .comment:not(:last-of-type, .has-children):before {
-      right: calc(-1 * var(--comment-indentation--md) + var(--sp));
+.indented > .comment:not(:last-of-type, .has-children):before {
+      inset-inline-start: calc(-1 * var(--comment-indentation--md) + var(--sp));
   }
     }
 
 @media (min-width: 43.75rem) {
 
-[dir="ltr"] .indented {
-    margin-left: var(--comment-indentation--md);
+.indented {
+    margin-inline-start: var(--comment-indentation--md);
+}
   }
 
-[dir="rtl"] .indented {
-    margin-right: var(--comment-indentation--md);
-  }
-  }
-
-[dir="ltr"] .show-hide-btn {
-  margin-left: var(--sp3);
-}
-
-[dir="rtl"] .show-hide-btn {
-  margin-right: var(--sp3);
-}
-
-[dir="ltr"] .show-hide-btn {
-  margin-right: 0;
-}
-
-[dir="rtl"] .show-hide-btn {
-  margin-left: 0;
-}
-
-[dir="ltr"] .show-hide-btn {
-  padding-left: 0;
-}
-
-[dir="rtl"] .show-hide-btn {
-  padding-right: 0;
-}
-
-[dir="ltr"] .show-hide-btn {
-  padding-right: 0;
-}
-
-[dir="rtl"] .show-hide-btn {
-  padding-left: 0;
-}
-
 .show-hide-btn {
-  margin-top: var(--sp2);
-  margin-bottom: 0;
-  padding-top: 0;
-  padding-bottom: 0;
+  margin-block-start: var(--sp2);
+  margin-block-end: 0;
+  margin-inline-start: var(--sp3);
+  margin-inline-end: 0;
+  padding-block: 0;
+  padding-inline-start: 0;
+  padding-inline-end: 0;
   cursor: pointer;
   color: var(--color-text-neutral-medium);
   border: 0;
@@ -412,11 +266,7 @@
 
 @media (min-width: 43.75rem) {
 
-[dir="ltr"] .show-hide-btn {
-    margin-left: 0;
-  }
-
-[dir="rtl"] .show-hide-btn {
-    margin-right: 0;
-  }
+.show-hide-btn {
+    margin-inline-start: 0;
+}
   }
diff --git a/core/themes/olivero/css/components/container-inline.module.css b/core/themes/olivero/css/components/container-inline.module.css
index b88a797f7e0..6bc96ebc349 100644
--- a/core/themes/olivero/css/components/container-inline.module.css
+++ b/core/themes/olivero/css/components/container-inline.module.css
@@ -16,12 +16,10 @@
 }
 
 .form-items-inline {
-  margin-top: -0.125em;
-  margin-bottom: -0.125em; /* 2px */
+  margin-block: -0.125em; /* 2px */
 }
 
 .form-items-inline > .form-item {
   display: inline-block;
-  margin-top: 0.125em;
-  margin-bottom: 0.125em;
+  margin-block: 0.125em;
 }
diff --git a/core/themes/olivero/css/components/content-moderation.css b/core/themes/olivero/css/components/content-moderation.css
index b6fde852a5b..b7167920443 100644
--- a/core/themes/olivero/css/components/content-moderation.css
+++ b/core/themes/olivero/css/components/content-moderation.css
@@ -23,24 +23,10 @@
 
 /* Width of the entire grid maxes out. */
 
-[dir="ltr"] .entity-moderation-form {
-  padding-left: var(--sp);
-}
-
-[dir="rtl"] .entity-moderation-form {
-  padding-right: var(--sp);
-}
-
-[dir="ltr"] .entity-moderation-form {
-  padding-right: var(--sp);
-}
-
-[dir="rtl"] .entity-moderation-form {
-  padding-left: var(--sp);
-}
-
 .entity-moderation-form {
   flex-direction: column;
+  padding-inline-start: var(--sp);
+  padding-inline-end: var(--sp);
   border: 1px solid var(--color--gray-95);
   background-color: var(--color--gray-100);
 }
@@ -57,28 +43,14 @@
 }
   }
 
-[dir="ltr"] .entity-moderation-form__item {
-  margin-right: var(--sp);
-}
-
-[dir="rtl"] .entity-moderation-form__item {
-  margin-left: var(--sp);
-}
-
 .entity-moderation-form__item {
   flex-basis: 0;
-}
-
-[dir="ltr"] .entity-moderation-form__item:last-child {
-    margin-right: 0;
-}
-
-[dir="rtl"] .entity-moderation-form__item:last-child {
-    margin-left: 0;
+  margin-inline-end: var(--sp);
 }
 
 .entity-moderation-form__item:last-child {
     align-self: flex-start;
+    margin-inline-end: 0;
   }
 
 @media (min-width: 43.75rem) {
@@ -88,16 +60,9 @@
   }
     }
 
-[dir="ltr"] .layout--content-narrow .entity-moderation-form,[dir="ltr"]  .layout--pass--content-narrow > * .entity-moderation-form,[dir="ltr"]  .layout--content-medium .entity-moderation-form,[dir="ltr"]  .layout--pass--content-medium > * .entity-moderation-form {
-    margin-left: 0;
-}
-
-[dir="rtl"] .layout--content-narrow .entity-moderation-form,[dir="rtl"]  .layout--pass--content-narrow > * .entity-moderation-form,[dir="rtl"]  .layout--content-medium .entity-moderation-form,[dir="rtl"]  .layout--pass--content-medium > * .entity-moderation-form {
-    margin-right: 0;
-}
-
 .layout--content-narrow .entity-moderation-form, .layout--pass--content-narrow > * .entity-moderation-form, .layout--content-medium .entity-moderation-form, .layout--pass--content-medium > * .entity-moderation-form {
     width: 100%;
+    margin-inline-start: 0;
   }
 
 @supports (width: max-content) {
@@ -109,47 +74,25 @@
 
 @media (min-width: 43.75rem) {
 
-[dir="ltr"] .layout--content-narrow .entity-moderation-form,[dir="ltr"]  .layout--pass--content-narrow > * .entity-moderation-form,[dir="ltr"]  .layout--content-medium .entity-moderation-form,[dir="ltr"]  .layout--pass--content-medium > * .entity-moderation-form {
-      margin-left: calc(-2 * (var(--grid-col-width) + var(--grid-gap)));
-  }
-
-[dir="rtl"] .layout--content-narrow .entity-moderation-form,[dir="rtl"]  .layout--pass--content-narrow > * .entity-moderation-form,[dir="rtl"]  .layout--content-medium .entity-moderation-form,[dir="rtl"]  .layout--pass--content-medium > * .entity-moderation-form {
-      margin-right: calc(-2 * (var(--grid-col-width) + var(--grid-gap)));
-  }
-
 .layout--content-narrow .entity-moderation-form, .layout--pass--content-narrow > * .entity-moderation-form, .layout--content-medium .entity-moderation-form, .layout--pass--content-medium > * .entity-moderation-form {
       width: calc(var(--grid-col-count) * var(--grid-col-width) + var(--grid-gap-count) * var(--grid-gap));
-      margin-top: var(--sp2);
-      margin-bottom: var(--sp4);
+      margin-block: var(--sp2) var(--sp4);
+      margin-inline-start: calc(-2 * (var(--grid-col-width) + var(--grid-gap)));
   }
     }
 
 @media (min-width: 62.5rem) {
 
-[dir="ltr"] .layout--content-narrow .entity-moderation-form,[dir="ltr"]  .layout--pass--content-narrow > * .entity-moderation-form,[dir="ltr"]  .layout--content-medium .entity-moderation-form,[dir="ltr"]  .layout--pass--content-medium > * .entity-moderation-form {
-      margin-left: calc(-1 * (var(--grid-col-width) + var(--grid-gap)));
-  }
-
-[dir="rtl"] .layout--content-narrow .entity-moderation-form,[dir="rtl"]  .layout--pass--content-narrow > * .entity-moderation-form,[dir="rtl"]  .layout--content-medium .entity-moderation-form,[dir="rtl"]  .layout--pass--content-medium > * .entity-moderation-form {
-      margin-right: calc(-1 * (var(--grid-col-width) + var(--grid-gap)));
-  }
-
 .layout--content-narrow .entity-moderation-form, .layout--pass--content-narrow > * .entity-moderation-form, .layout--content-medium .entity-moderation-form, .layout--pass--content-medium > * .entity-moderation-form {
       width: calc(12 * var(--grid-col-width) + 11 * var(--grid-gap));
+      margin-inline-start: calc(-1 * (var(--grid-col-width) + var(--grid-gap)));
   }
     }
 
 @media (min-width: 90rem) {
 
-[dir="ltr"] .layout--content-narrow .entity-moderation-form,[dir="ltr"]  .layout--pass--content-narrow > * .entity-moderation-form,[dir="ltr"]  .layout--content-medium .entity-moderation-form,[dir="ltr"]  .layout--pass--content-medium > * .entity-moderation-form {
-      margin-left: 0;
-  }
-
-[dir="rtl"] .layout--content-narrow .entity-moderation-form,[dir="rtl"]  .layout--pass--content-narrow > * .entity-moderation-form,[dir="rtl"]  .layout--content-medium .entity-moderation-form,[dir="rtl"]  .layout--pass--content-medium > * .entity-moderation-form {
-      margin-right: 0;
-  }
-
 .layout--content-narrow .entity-moderation-form, .layout--pass--content-narrow > * .entity-moderation-form, .layout--content-medium .entity-moderation-form, .layout--pass--content-medium > * .entity-moderation-form {
       width: calc(10 * var(--grid-col-width) + 11 * var(--grid-gap));
+      margin-inline-start: 0;
   }
     }
diff --git a/core/themes/olivero/css/components/details.css b/core/themes/olivero/css/components/details.css
index 6d3a625c1cf..6bd0951faaa 100644
--- a/core/themes/olivero/css/components/details.css
+++ b/core/themes/olivero/css/components/details.css
@@ -30,8 +30,7 @@
 
 .olivero-details {
   display: block;
-  margin-top: var(--sp1);
-  margin-bottom: var(--sp1);
+  margin-block: var(--sp1);
   color: inherit;
   border: var(--details-border-width) solid var(--color--gray-95);
   border-radius: var(--border-radius);
@@ -40,26 +39,11 @@
 
 /* Details summary styles */
 
-[dir="ltr"] .olivero-details__summary {
-  padding-left: var(--sp2);
-}
-
-[dir="rtl"] .olivero-details__summary {
-  padding-right: var(--sp2);
-}
-
-[dir="ltr"] .olivero-details__summary {
-  padding-right: var(--sp1);
-}
-
-[dir="rtl"] .olivero-details__summary {
-  padding-left: var(--sp1);
-}
-
 .olivero-details__summary {
   position: relative;
-  padding-top: var(--sp1);
-  padding-bottom: var(--sp1);
+  padding-block: var(--sp1);
+  padding-inline-start: var(--sp2);
+  padding-inline-end: var(--sp1);
   list-style: none;
   cursor: pointer;
   transition: var(--details-summary-transition);
@@ -75,17 +59,10 @@
 
 /* Arrow icon */
 
-[dir="ltr"] .olivero-details__summary:before {
-  left: var(--sp0-75);
-}
-
-[dir="rtl"] .olivero-details__summary:before {
-  right: var(--sp0-75);
-}
-
 .olivero-details__summary:before {
   position: absolute;
-  top: 50%;
+  inset-block-start: 50%;
+  inset-inline-start: var(--sp0-75);
   display: block;
   width: 0.625rem;
   height: 0.625rem;
@@ -103,10 +80,7 @@
 
 .olivero-details__summary:after {
   position: absolute;
-  top: calc(var(--details-border-width) * -1);
-  right: calc(var(--details-border-width) * -1);
-  bottom: calc(var(--details-border-width) * -1);
-  left: calc(var(--details-border-width) * -1);
+  inset: calc(var(--details-border-width) * -1);
   content: "";
   pointer-events: none;
   opacity: 0;
@@ -143,7 +117,7 @@
 /* Rotate arrow icon of the details summary, when details expanded */
 
 .olivero-details[open] > .olivero-details__summary::before {
-  margin-top: -2px;
+  margin-block-start: -2px;
   transform: translateY(-50%) rotate(135deg);
 }
 
@@ -155,32 +129,18 @@
 
 @media (min-width: 62.5rem) {
 
-[dir="ltr"] .olivero-details__wrapper {
-    margin-left: var(--sp2);
-  }
-
-[dir="rtl"] .olivero-details__wrapper {
-    margin-right: var(--sp2);
-  }
-
-[dir="ltr"] .olivero-details__wrapper {
-    margin-right: var(--sp2);
-  }
-
-[dir="rtl"] .olivero-details__wrapper {
-    margin-left: var(--sp2);
-  }
-
 .olivero-details__wrapper {
-    margin-top: var(--sp1-5);
-    margin-bottom: var(--sp1-5);
+    margin-block-start: var(--sp1-5);
+    margin-block-end: var(--sp1-5);
+    margin-inline-start: var(--sp2);
+    margin-inline-end: var(--sp2);
 }
   }
 
 /* Description */
 
 .olivero-details__description {
-  margin-bottom: var(--sp1);
+  margin-block-end: var(--sp1);
   color: var(--color-text-neutral-medium);
   font-size: var(--font-size-xs);
   line-height: var(--line-height-s);
diff --git a/core/themes/olivero/css/components/dropbutton.css b/core/themes/olivero/css/components/dropbutton.css
index 9737357c286..3e8b819a655 100644
--- a/core/themes/olivero/css/components/dropbutton.css
+++ b/core/themes/olivero/css/components/dropbutton.css
@@ -27,70 +27,37 @@
     filter: drop-shadow(0 2px 2px var(--dropbutton--active-bg-color));
   }
 
-[dir="ltr"] .dropbutton-widget {
-  padding-right: var(--dropbutton--height);
-}
-
-[dir="rtl"] .dropbutton-widget {
-  padding-left: var(--dropbutton--height);
-}
-
 .dropbutton-widget {
   position: relative;
   width: max-content;
   height: var(--dropbutton--height);
+  padding-inline-end: var(--dropbutton--height);
   border-radius: var(--dropbutton--border-radius);
 }
 
-[dir="ltr"] .dropbutton-single .dropbutton-widget {
-    padding-right: 0;
-}
-
-[dir="rtl"] .dropbutton-single .dropbutton-widget {
-    padding-left: 0;
+.dropbutton-single .dropbutton-widget {
+    padding-inline-end: 0;
 }
 
 .dropbutton-wrapper.open .dropbutton-widget {
     border-radius: var(--dropbutton--border-radius) var(--dropbutton--border-radius) 0 0;
 }
 
-[dir="ltr"] .dropbutton {
-  margin-left: 0;
-}
-
-[dir="rtl"] .dropbutton {
-  margin-right: 0;
-}
-
-[dir="ltr"] .dropbutton {
-  padding-left: 0;
-}
-
-[dir="rtl"] .dropbutton {
-  padding-right: 0;
-}
-
 .dropbutton {
   height: var(--dropbutton--height);
-  margin-top: 0;
-  margin-bottom: 0;
+  margin-block: 0;
+  margin-inline-start: 0;
+  padding-inline-start: 0;
   list-style: none;
   font-size: var(--dropbutton--font-size);
 }
 
 /* This is the button that expands/collapses the secondary options. */
 
-[dir="ltr"] .dropbutton-toggle button {
-  right: 0;
-}
-
-[dir="rtl"] .dropbutton-toggle button {
-  left: 0;
-}
-
 .dropbutton-toggle button {
   position: absolute;
   top: 0;
+  inset-inline-end: 0;
   display: flex;
   align-items: center;
   justify-content: center;
@@ -128,15 +95,8 @@
 
 /* This is the first <li> element in the list of actions. */
 
-[dir="ltr"] .dropbutton-action:first-child {
-    margin-right: 2px;
-}
-
-[dir="rtl"] .dropbutton-action:first-child {
-    margin-left: 2px;
-}
-
 .dropbutton-action:first-child {
+    margin-inline-end: 2px;
     border: solid 1px transparent;
     border-radius: var(--dropbutton--border-radius) 0 0 var(--dropbutton--border-radius); /* LTR */
     background: var(--dropbutton--active-bg-color);
diff --git a/core/themes/olivero/css/components/embedded-media.css b/core/themes/olivero/css/components/embedded-media.css
index 0d339ca840b..9bb2bb60539 100644
--- a/core/themes/olivero/css/components/embedded-media.css
+++ b/core/themes/olivero/css/components/embedded-media.css
@@ -27,25 +27,10 @@ figure {
   background: var(--color--gray-100);
 }
 
-[dir="ltr"] figcaption {
-  padding-left: var(--sp0-5);
-}
-
-[dir="rtl"] figcaption {
-  padding-right: var(--sp0-5);
-}
-
-[dir="ltr"] figcaption {
-  padding-right: var(--sp0-5);
-}
-
-[dir="rtl"] figcaption {
-  padding-left: var(--sp0-5);
-}
-
 figcaption {
-  padding-top: var(--sp0-5);
-  padding-bottom: var(--sp0-5);
+  padding-block: var(--sp0-5);
+  padding-inline-start: var(--sp0-5);
+  padding-inline-end: var(--sp0-5);
   color: var(--color-text-neutral-medium);
   background: var(--color--gray-100);
   font-family: var(--font-serif);
@@ -56,81 +41,30 @@ figcaption {
 
 @media (min-width: 31.25rem) {
 
-[dir="ltr"] figcaption {
-    padding-left: var(--sp);
-  }
-
-[dir="rtl"] figcaption {
-    padding-right: var(--sp);
-  }
-
-[dir="ltr"] figcaption {
-    padding-right: var(--sp);
-  }
-
-[dir="rtl"] figcaption {
-    padding-left: var(--sp);
-  }
-
 figcaption {
-    padding-top: var(--sp);
-    padding-bottom: var(--sp);
+    padding-block: var(--sp);
+    padding-inline-start: var(--sp);
+    padding-inline-end: var(--sp);
 }
   }
 
-[dir="ltr"] .align-right {
-  margin-left: 0;
-}
-
-[dir="rtl"] .align-right {
-  margin-right: 0;
-}
-
-[dir="ltr"] .align-right {
-  margin-right: 0;
-}
-
-[dir="rtl"] .align-right {
-  margin-left: 0;
-}
-
 .align-right {
   float: none; /* Override core's align.module.css. */
   max-width: 100%;
-  margin-top: var(--sp3);
-  margin-bottom: var(--sp3);
+  margin-block: var(--sp3);
+  margin-inline-start: 0;
+  margin-inline-end: 0;
 }
 
 @media (min-width: 43.75rem) {
 
-[dir="ltr"] .align-right {
-    float: right;
-  }
-
-[dir="rtl"] .align-right {
-    float: left;
-  }
-
-[dir="ltr"] .align-right {
-    margin-left: var(--sp);
-  }
-
-[dir="rtl"] .align-right {
-    margin-right: var(--sp);
-  }
-
-[dir="ltr"] .align-right {
-    margin-right: 0;
-  }
-
-[dir="rtl"] .align-right {
-    margin-left: 0;
-  }
-
 .align-right {
+    float: inline-end;
     max-width: 50%;
-    margin-top: var(--sp);
-    margin-bottom: var(--sp);
+    margin-block-start: var(--sp);
+    margin-block-end: var(--sp);
+    margin-inline-start: var(--sp);
+    margin-inline-end: 0;
 }
   }
 
@@ -140,109 +74,54 @@ figcaption {
 
 @media (min-width: 43.75rem) {
 
-[dir="ltr"] .layout--content-narrow .align-right,[dir="ltr"] 
+.layout--content-narrow .align-right,
 .layout--pass--content-narrow > * .align-right {
-    margin-right: calc(-1 * ((var(--grid-col-width) + var(--grid-gap))));
-  }
-
-[dir="rtl"] .layout--content-narrow .align-right,[dir="rtl"] 
-.layout--pass--content-narrow > * .align-right {
-    margin-left: calc(-1 * ((var(--grid-col-width) + var(--grid-gap))));
-  }
+    margin-inline-end: calc(-1 * ((var(--grid-col-width) + var(--grid-gap))));
+}
   }
 
 @media (min-width: 62.5rem) {
 
-[dir="ltr"] .layout--content-narrow .align-right,[dir="ltr"] 
+.layout--content-narrow .align-right,
 .layout--pass--content-narrow > * .align-right {
-    margin-right: calc(-2 * ((var(--grid-col-width) + var(--grid-gap))));
-  }
-
-[dir="rtl"] .layout--content-narrow .align-right,[dir="rtl"] 
-.layout--pass--content-narrow > * .align-right {
-    margin-left: calc(-2 * ((var(--grid-col-width) + var(--grid-gap))));
-  }
+    margin-inline-end: calc(-2 * ((var(--grid-col-width) + var(--grid-gap))));
+}
   }
 
 @media (min-width: 75rem) {
 
-[dir="ltr"] .layout--content-narrow .align-right,[dir="ltr"] 
+.layout--content-narrow .align-right,
 .layout--pass--content-narrow > * .align-right {
-    margin-right: calc(-3 * ((var(--grid-col-width) + var(--grid-gap))));
-  }
-
-[dir="rtl"] .layout--content-narrow .align-right,[dir="rtl"] 
-.layout--pass--content-narrow > * .align-right {
-    margin-left: calc(-3 * ((var(--grid-col-width) + var(--grid-gap))));
-  }
+    margin-inline-end: calc(-3 * ((var(--grid-col-width) + var(--grid-gap))));
+}
   }
 
 @media (min-width: 90rem) {
 
-[dir="ltr"] .layout--content-narrow .align-right,[dir="ltr"] 
+.layout--content-narrow .align-right,
 .layout--pass--content-narrow > * .align-right {
-    margin-right: calc(-3 * ((var(--grid-col-width) + var(--grid-gap))));
+    margin-inline-end: calc(-3 * ((var(--grid-col-width) + var(--grid-gap))));
+}
   }
 
-[dir="rtl"] .layout--content-narrow .align-right,[dir="rtl"] 
-.layout--pass--content-narrow > * .align-right {
-    margin-left: calc(-3 * ((var(--grid-col-width) + var(--grid-gap))));
-  }
-  }
-
-[dir="ltr"] .align-left {
-  margin-left: 0;
-}
-
-[dir="rtl"] .align-left {
-  margin-right: 0;
-}
-
-[dir="ltr"] .align-left {
-  margin-right: 0;
-}
-
-[dir="rtl"] .align-left {
-  margin-left: 0;
-}
-
 .align-left {
   float: none; /* Override core's align.module.css. */
   max-width: 100%;
-  margin-top: var(--sp3);
-  margin-bottom: var(--sp3);
+  margin-block-start: var(--sp3);
+  margin-block-end: var(--sp3);
+  margin-inline-start: 0;
+  margin-inline-end: 0;
 }
 
 @media (min-width: 43.75rem) {
 
-[dir="ltr"] .align-left {
-    float: left;
-  }
-
-[dir="rtl"] .align-left {
-    float: right;
-  }
-
-[dir="ltr"] .align-left {
-    margin-left: 0;
-  }
-
-[dir="rtl"] .align-left {
-    margin-right: 0;
-  }
-
-[dir="ltr"] .align-left {
-    margin-right: var(--sp2);
-  }
-
-[dir="rtl"] .align-left {
-    margin-left: var(--sp2);
-  }
-
 .align-left {
+    float: inline-start;
     max-width: 50%;
-    margin-top: var(--sp);
-    margin-bottom: var(--sp); /* Extra right margins in case of aligning next to lists. */
+    margin-block-start: var(--sp);
+    margin-block-end: var(--sp);
+    margin-inline-start: 0;
+    margin-inline-end: var(--sp2); /* Extra right margins in case of aligning next to lists. */
 }
   }
 
@@ -250,22 +129,16 @@ figcaption {
 
 @media (min-width: 43.75rem) {
 
-[dir="ltr"] .layout--content-narrow .align-left,[dir="ltr"] 
+.layout--content-narrow .align-left,
 .layout--pass--content-narrow > * .align-left {
-    margin-left: calc(-1 * ((var(--grid-col-width) + var(--grid-gap))));
-  }
-
-[dir="rtl"] .layout--content-narrow .align-left,[dir="rtl"] 
-.layout--pass--content-narrow > * .align-left {
-    margin-right: calc(-1 * ((var(--grid-col-width) + var(--grid-gap))));
-  }
+    margin-inline-start: calc(-1 * ((var(--grid-col-width) + var(--grid-gap))));
+}
   }
 
 .align-center img,
 .align-center video,
 .align-center audio {
-  margin-left: auto;
-  margin-right: auto;
+  margin-inline: auto;
 }
 
 .media-oembed-content {
diff --git a/core/themes/olivero/css/components/feed.css b/core/themes/olivero/css/components/feed.css
index 00ff21e6a14..1990007415e 100644
--- a/core/themes/olivero/css/components/feed.css
+++ b/core/themes/olivero/css/components/feed.css
@@ -41,14 +41,6 @@
   font-weight: 600;
 }
 
-[dir="ltr"] .feed-icon__icon {
-  margin-left: var(--sp0-5);
-}
-
-[dir="rtl"] .feed-icon__icon {
-  margin-right: var(--sp0-5);
-}
-
 .feed-icon__icon {
   display: flex;
   flex-shrink: 0;
@@ -56,6 +48,7 @@
   justify-content: center;
   width: var(--sp1-5);
   height: var(--sp1-5);
+  margin-inline-start: var(--sp0-5);
   color: var(--color--white);
   background-color: var(--color--primary-50);
 }
diff --git a/core/themes/olivero/css/components/field.css b/core/themes/olivero/css/components/field.css
index f71f06f9269..87568149cc7 100644
--- a/core/themes/olivero/css/components/field.css
+++ b/core/themes/olivero/css/components/field.css
@@ -24,21 +24,21 @@
 /* Width of the entire grid maxes out. */
 
 .field:not(:last-child) {
-  margin-bottom: var(--sp2);
+  margin-block-end: var(--sp2);
 }
 
 .node--view-mode-teaser .field {
-  margin-bottom: var(--sp);
+  margin-block-end: var(--sp);
 }
 
 .node--view-mode-teaser .field:last-child {
-    margin-bottom: 0;
+    margin-block-end: 0;
   }
 
 @media (min-width: 62.5rem) {
 
 .node--view-mode-teaser .field {
-    margin-bottom: var(--sp2);
+    margin-block-end: var(--sp2);
 }
   }
 
@@ -46,26 +46,15 @@
   font-weight: bold;
 }
 
-[dir="ltr"] .field--label-inline .field__label,[dir="ltr"] 
+.field--label-inline .field__label,
 .field--label-inline .field__items {
-  float: left;
+  float: inline-start;
 }
 
-[dir="rtl"] .field--label-inline .field__label,[dir="rtl"] 
+.field--label-inline .field__label,
+.field--label-inline > .field__item,
 .field--label-inline .field__items {
-  float: right;
-}
-
-[dir="ltr"] .field--label-inline .field__label,[dir="ltr"] 
-.field--label-inline > .field__item,[dir="ltr"] 
-.field--label-inline .field__items {
-  padding-right: 0.5em;
-}
-
-[dir="rtl"] .field--label-inline .field__label,[dir="rtl"] 
-.field--label-inline > .field__item,[dir="rtl"] 
-.field--label-inline .field__items {
-  padding-left: 0.5em;
+  padding-inline-end: 0.5em;
 }
 
 .field--label-inline .field__label::after {
diff --git a/core/themes/olivero/css/components/fieldset.css b/core/themes/olivero/css/components/fieldset.css
index 2d61b4ced8b..311d62a482a 100644
--- a/core/themes/olivero/css/components/fieldset.css
+++ b/core/themes/olivero/css/components/fieldset.css
@@ -23,44 +23,14 @@
 
 /* Width of the entire grid maxes out. */
 
-[dir="ltr"] .fieldset {
-  margin-left: 0;
-}
-
-[dir="rtl"] .fieldset {
-  margin-right: 0;
-}
-
-[dir="ltr"] .fieldset {
-  margin-right: 0;
-}
-
-[dir="rtl"] .fieldset {
-  margin-left: 0;
-}
-
-[dir="ltr"] .fieldset {
-  padding-left: 0;
-}
-
-[dir="rtl"] .fieldset {
-  padding-right: 0;
-}
-
-[dir="ltr"] .fieldset {
-  padding-right: 0;
-}
-
-[dir="rtl"] .fieldset {
-  padding-left: 0;
-}
-
 .fieldset {
   min-width: 0;
-  margin-top: var(--sp1);
-  margin-bottom: var(--sp1);
-  padding-top: 0;
-  padding-bottom: 0;
+  margin-block: var(--sp1);
+  margin-inline-start: 0;
+  margin-inline-end: 0;
+  padding-block: 0;
+  padding-inline-start: 0;
+  padding-inline-end: 0;
   color: inherit;
   border: solid 2px var(--color--gray-45);
   border-radius: var(--border-radius);
@@ -106,7 +76,7 @@ _:-ms-fullscreen,
       }
 
 .fieldset__legend--composite {
-  margin-top: 2px;
+  margin-block-start: 2px;
   color: inherit;
 }
 
@@ -118,26 +88,11 @@ _:-ms-fullscreen,
   color: inherit;
 }
 
-[dir="ltr"] .fieldset__label {
-  padding-left: var(--sp1);
-}
-
-[dir="rtl"] .fieldset__label {
-  padding-right: var(--sp1);
-}
-
-[dir="ltr"] .fieldset__label {
-  padding-right: var(--sp1);
-}
-
-[dir="rtl"] .fieldset__label {
-  padding-left: var(--sp1);
-}
-
 .fieldset__label {
   display: block;
-  padding-top: var(--sp0-5);
-  padding-bottom: var(--sp0-5);
+  padding-block: var(--sp0-5);
+  padding-inline-start: var(--sp1);
+  padding-inline-end: var(--sp1);
   color: var(--color--white);
   line-height: var(--line-height-s);
 }
@@ -147,8 +102,7 @@ _:-ms-fullscreen,
 }
 
 .fieldset__description {
-  margin-top: var(--sp0-5);
-  margin-bottom: var(--sp0-5);
+  margin-block: var(--sp0-5);
   font-size: var(--font-size-xs);
   line-height: var(--line-height-s);
 }
@@ -157,17 +111,9 @@ _:-ms-fullscreen,
   color: var(--input--disabled-fg-color);
 }
 
-[dir="ltr"] .fieldset__error-message {
-  padding-left: var(--sp1-5);
-}
-
-[dir="rtl"] .fieldset__error-message {
-  padding-right: var(--sp1-5);
-}
-
 .fieldset__error-message {
-  margin-top: var(--sp0-5);
-  margin-bottom: var(--sp0-5);
+  margin-block: var(--sp0-5);
+  padding-inline-start: var(--sp1-5);
   color: var(--color--red);
   background-image: url("data:image/svg+xml,%3Csvg width='18' height='18' viewBox='0 0 18 18' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath fill='%23E33F1E' d='M9 0C4.03125 0 0 4.03125 0 9C0 13.9688 4.03125 18 9 18C13.9687 18 18 13.9688 18 9C18 4.03125 13.9687 0 9 0ZM10.5 14.6133C10.5 14.8242 10.3359 15 10.1367 15H7.88672C7.67578 15 7.5 14.8242 7.5 14.6133V12.3867C7.5 12.1758 7.67578 12 7.88672 12H10.1367C10.3359 12 10.5 12.1758 10.5 12.3867V14.6133ZM10.4766 10.582C10.4648 10.7461 10.2891 10.875 10.0781 10.875H7.91016C7.6875 10.875 7.51172 10.7461 7.51172 10.582L7.3125 3.30469C7.3125 3.22266 7.34766 3.14063 7.42969 3.09375C7.5 3.03516 7.60547 3 7.71094 3H10.2891C10.3945 3 10.5 3.03516 10.5703 3.09375C10.6523 3.14063 10.6875 3.22266 10.6875 3.30469L10.4766 10.582Z'/%3E%3C/svg%3E");
   background-repeat: no-repeat;
@@ -193,7 +139,7 @@ _:-ms-fullscreen,
 }
 
 .fieldset__legend--invisible ~ .fieldset__wrapper {
-  margin-top: 0;
+  margin-block-start: 0;
   padding: 0;
 }
 
@@ -203,44 +149,14 @@ _:-ms-fullscreen,
   border-bottom-left-radius: var(--border-radius);
 }
 
-[dir="ltr"] .fieldset__wrapper--group {
-  margin-left: 0;
-}
-
-[dir="rtl"] .fieldset__wrapper--group {
-  margin-right: 0;
-}
-
-[dir="ltr"] .fieldset__wrapper--group {
-  margin-right: 0;
-}
-
-[dir="rtl"] .fieldset__wrapper--group {
-  margin-left: 0;
-}
-
 .fieldset__wrapper--group {
-  margin-top: 0;
-  margin-bottom: 0;
-}
-
-[dir="ltr"] .fieldset__wrapper > .container-inline {
-  padding-left: 0;
-}
-
-[dir="rtl"] .fieldset__wrapper > .container-inline {
-  padding-right: 0;
-}
-
-[dir="ltr"] .fieldset__wrapper > .container-inline {
-  padding-right: 0;
-}
-
-[dir="rtl"] .fieldset__wrapper > .container-inline {
-  padding-left: 0;
+  margin-block: 0;
+  margin-inline-start: 0;
+  margin-inline-end: 0;
 }
 
 .fieldset__wrapper > .container-inline {
-  padding-top: 0;
-  padding-bottom: 0;
+  padding-block: 0;
+  padding-inline-start: 0;
+  padding-inline-end: 0;
 }
diff --git a/core/themes/olivero/css/components/footer.css b/core/themes/olivero/css/components/footer.css
index cbc131e8c11..35fc39f38a6 100644
--- a/core/themes/olivero/css/components/footer.css
+++ b/core/themes/olivero/css/components/footer.css
@@ -29,28 +29,17 @@
   background: linear-gradient(180deg, var(--color--gray-5) 0%, var(--color--gray-10) 100%);
 }
 
-[dir="ltr"] .site-footer .menu {
-    margin-left: 0;
-}
-
-[dir="rtl"] .site-footer .menu {
-    margin-right: 0;
-}
-
 .site-footer .menu {
+    margin-inline-start: 0;
     list-style: none;
   }
 
-[dir="ltr"] .site-footer .menu ul {
-      margin-left: var(--sp);
-}
-
-[dir="rtl"] .site-footer .menu ul {
-      margin-right: var(--sp);
-}
+.site-footer .menu ul {
+      margin-inline-start: var(--sp);
+    }
 
 .site-footer .menu li {
-      margin-bottom: var(--sp0-5);
+      margin-block-end: var(--sp0-5);
     }
 
 .site-footer a {
@@ -62,10 +51,7 @@
     }
 
 @media (min-width: 75rem) {
-  [dir="ltr"] body:not(.is-always-mobile-nav) .site-footer {
-    border-left: solid var(--content-left) var(--color--black);
-  }
-  [dir="rtl"] body:not(.is-always-mobile-nav) .site-footer {
-    border-right: solid var(--content-left) var(--color--black);
+  body:not(.is-always-mobile-nav) .site-footer {
+    border-inline-start: solid var(--content-left) var(--color--black);
   }
 }
diff --git a/core/themes/olivero/css/components/form-boolean.css b/core/themes/olivero/css/components/form-boolean.css
index 283b73c150f..0c6c45a32c2 100644
--- a/core/themes/olivero/css/components/form-boolean.css
+++ b/core/themes/olivero/css/components/form-boolean.css
@@ -90,16 +90,9 @@ input.error[type="checkbox"]::-ms-check, input.error[type="radio"]::-ms-check {
     border: 1px solid var(--color--red);
   }
 
-[dir="ltr"] input[type="checkbox"] + label,[dir="ltr"]  input[type="radio"] + label {
-    padding-left: var(--sp0-5);
-}
-
-[dir="rtl"] input[type="checkbox"] + label,[dir="rtl"]  input[type="radio"] + label {
-    padding-right: var(--sp0-5);
-}
-
 input[type="checkbox"] + label, input[type="radio"] + label {
     display: inline-block;
+    padding-inline-start: var(--sp0-5);
   }
 
 input[type="checkbox"]:checked {
@@ -128,6 +121,5 @@ input.error[type="radio"]:focus {
   }
 
 .form-type-boolean {
-  margin-top: var(--sp1);
-  margin-bottom: var(--sp1);
+  margin-block: var(--sp1);
 }
diff --git a/core/themes/olivero/css/components/form-select.css b/core/themes/olivero/css/components/form-select.css
index 55880c6fdf8..f4c27fc9c0c 100644
--- a/core/themes/olivero/css/components/form-select.css
+++ b/core/themes/olivero/css/components/form-select.css
@@ -27,27 +27,12 @@
   --form-element-select-icon: url("data:image/svg+xml,%3csvg width='18' height='11' viewBox='0 0 18 11' fill='none' xmlns='http://www.w3.org/2000/svg'%3e%3cpath d='M18 1.49699C18 1.35271 17.9279 1.19038 17.8196 1.08216L16.9178 0.18036C16.8096 0.0721439 16.6473 0 16.503 0C16.3587 0 16.1964 0.0721439 16.0882 0.18036L9 7.26854L1.91182 0.18036C1.80361 0.0721439 1.64128 0 1.49699 0C1.33467 0 1.19038 0.0721439 1.08216 0.18036L0.180361 1.08216C0.0721442 1.19038 0 1.35271 0 1.49699C0 1.64128 0.0721442 1.80361 0.180361 1.91182L8.58517 10.3166C8.69339 10.4248 8.85571 10.497 9 10.497C9.14429 10.497 9.30661 10.4248 9.41483 10.3166L17.8196 1.91182C17.9279 1.80361 18 1.64128 18 1.49699Z' fill='%235D7585'/%3e%3c/svg%3e");
 }
 
-[dir="ltr"] select {
-  padding-left: var(--sp);
-}
-
-[dir="rtl"] select {
-  padding-right: var(--sp);
-}
-
-[dir="ltr"] select {
-  padding-right: var(--sp3);
-}
-
-[dir="rtl"] select {
-  padding-left: var(--sp3);
-}
-
 select {
   max-width: 100%;
   height: var(--sp3);
-  padding-top: 0;
-  padding-bottom: 0;
+  padding-block: 0;
+  padding-inline-start: var(--sp);
+  padding-inline-end: var(--sp3);
   color: var(--color-text-neutral-loud);
   border: 1px solid var(--color--gray-60);
   border-radius: var(--border-radius);
@@ -114,15 +99,8 @@ select.form-element--small {
 
 @media (forced-colors: active) {
 
-[dir="ltr"] select {
-    padding-right: var(--sp);
-  }
-
-[dir="rtl"] select {
-    padding-left: var(--sp);
-  }
-
 select {
+    padding-inline-end: var(--sp);
     background-image: none;
     -webkit-appearance: listbox;
     appearance: listbox; /* Default <select> appearance value for modern browsers. */
@@ -142,15 +120,8 @@ select {
 
 @media screen and (-ms-high-contrast: active) {
 
-[dir="ltr"] select {
-    padding-right: 0;
-  }
-
-[dir="rtl"] select {
-    padding-left: 0;
-  }
-
 select {
+    padding-inline-end: 0;
 
     /* Re-enable default chevron for Internet Explorer. */
 }
diff --git a/core/themes/olivero/css/components/form-text.css b/core/themes/olivero/css/components/form-text.css
index 20d31b7d7df..49b70ee3963 100644
--- a/core/themes/olivero/css/components/form-text.css
+++ b/core/themes/olivero/css/components/form-text.css
@@ -116,31 +116,15 @@ textarea {
 
 /* Ensure that date field isn't larger than other fields. */
 
-[dir="ltr"] [type="date"]::-webkit-datetime-edit-fields-wrapper {
-    padding-left: 0;
-}
-
-[dir="rtl"] [type="date"]::-webkit-datetime-edit-fields-wrapper {
-    padding-right: 0;
-}
-
-[dir="ltr"] [type="date"]::-webkit-datetime-edit-fields-wrapper {
-    padding-right: 0;
-}
-
-[dir="rtl"] [type="date"]::-webkit-datetime-edit-fields-wrapper {
-    padding-left: 0;
-}
-
 [type="date"]::-webkit-datetime-edit-fields-wrapper {
-    padding-top: 0;
-    padding-bottom: 0;
+    padding-block: 0;
+    padding-inline-start: 0;
+    padding-inline-end: 0;
   }
 
 [type="file"] {
   height: auto;
-  padding-top: var(--sp0-75);
-  padding-bottom: var(--sp0-75);
+  padding-block: var(--sp0-75);
 }
 
 [type="color"] {
diff --git a/core/themes/olivero/css/components/form.css b/core/themes/olivero/css/components/form.css
index a39b8c837d8..6146e23d168 100644
--- a/core/themes/olivero/css/components/form.css
+++ b/core/themes/olivero/css/components/form.css
@@ -32,13 +32,11 @@
  */
 
 .form-item {
-  margin-top: var(--sp1);
-  margin-bottom: var(--sp1);
+  margin-block: var(--sp1);
 }
 
 .form-item__label--multiple-value-form {
-  margin-top: 0;
-  margin-bottom: 0;
+  margin-block: 0;
   font-size: inherit;
   font-weight: inherit;
   line-height: inherit;
@@ -52,8 +50,7 @@
 
 tr .form-item,
 .container-inline .form-item {
-  margin-top: var(--sp0-5);
-  margin-bottom: var(--sp0-5);
+  margin-block: var(--sp0-5);
 }
 
 /**
@@ -62,21 +59,15 @@ tr .form-item,
 
 .form-item__label {
   display: block;
-  margin-top: var(--sp0-5);
-  margin-bottom: var(--sp0-5);
+  margin-block: var(--sp0-5);
 }
 
-[dir="ltr"] .container-inline .form-item__label {
-  margin-right: 1em;
-}
-
-[dir="rtl"] .container-inline .form-item__label {
-  margin-left: 1em;
+.container-inline .form-item__label {
+  margin-inline-end: 1em;
 }
 
 .form-item__label--multiple-value-form {
-  margin-top: 0;
-  margin-bottom: 0;
+  margin-block: 0;
   font-size: inherit;
   font-weight: inherit;
   line-height: inherit;
@@ -106,8 +97,7 @@ tr .form-item,
   display: inline-block;
   width: 0.5rem;
   height: 0.5rem;
-  margin-left: 0.3em;
-  margin-right: 0.3em;
+  margin-inline: 0.3em;
   content: "";
   vertical-align: text-top;
   /* Use a background image to prevent screen readers from announcing the text. */
@@ -130,32 +120,23 @@ tr .form-item,
  */
 
 .form-item__description {
-  margin-top: var(--sp0-5);
-  margin-bottom: var(--sp0-5);
+  margin-block: var(--sp0-5);
   max-width: 60ch;
   font-size: var(--font-size-s);
   line-height: var(--line-height-s);
 }
 
 .field-multiple-table + .form-item__description {
-  margin-top: 0;
+  margin-block-start: 0;
 }
 
 /**
  * Error message (Inline form errors).
  */
 
-[dir="ltr"] .form-item--error-message {
-  padding-left: var(--sp1-5);
-}
-
-[dir="rtl"] .form-item--error-message {
-  padding-right: var(--sp1-5);
-}
-
 .form-item--error-message {
-  margin-top: var(--sp0-5);
-  margin-bottom: var(--sp0-5);
+  margin-block: var(--sp0-5);
+  padding-inline-start: var(--sp1-5);
   color: var(--color--red);
   background-image: url("data:image/svg+xml,%3Csvg width='18' height='18' viewBox='0 0 18 18' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath fill='%23E33F1E' d='M9 0C4.03125 0 0 4.03125 0 9C0 13.9688 4.03125 18 9 18C13.9687 18 18 13.9688 18 9C18 4.03125 13.9687 0 9 0ZM10.5 14.6133C10.5 14.8242 10.3359 15 10.1367 15H7.88672C7.67578 15 7.5 14.8242 7.5 14.6133V12.3867C7.5 12.1758 7.67578 12 7.88672 12H10.1367C10.3359 12 10.5 12.1758 10.5 12.3867V14.6133ZM10.4766 10.582C10.4648 10.7461 10.2891 10.875 10.0781 10.875H7.91016C7.6875 10.875 7.51172 10.7461 7.51172 10.582L7.3125 3.30469C7.3125 3.22266 7.34766 3.14063 7.42969 3.09375C7.5 3.03516 7.60547 3 7.71094 3H10.2891C10.3945 3 10.5 3.03516 10.5703 3.09375C10.6523 3.14063 10.6875 3.22266 10.6875 3.30469L10.4766 10.582Z'/%3E%3C/svg%3E");
   background-repeat: no-repeat;
@@ -184,14 +165,12 @@ tr .form-item,
   display: flex;
   flex-wrap: wrap;
   align-items: flex-start;
-  margin-top: var(--sp0-5);
-  margin-bottom: var(--sp0-5);
+  margin-block: var(--sp0-5);
 }
 
 .form-actions .button,
 .form-actions .action-link {
-  margin-top: var(--sp0-5);
-  margin-bottom: var(--sp0-5);
+  margin-block: var(--sp0-5);
 }
 
 .form-actions .ajax-progress--throbber {
@@ -216,16 +195,10 @@ tr .form-item,
   min-width: 1px;
 }
 
-[dir="ltr"] .form-item--editor-format .form-item__label,[dir="ltr"] 
-.form-item--editor-format .form-item__prefix,[dir="ltr"] 
+.form-item--editor-format .form-item__label,
+.form-item--editor-format .form-item__prefix,
 .form-item--editor-format .form-item__suffix {
-  margin-right: var(--sp0-5);
-}
-
-[dir="rtl"] .form-item--editor-format .form-item__label,[dir="rtl"] 
-.form-item--editor-format .form-item__prefix,[dir="rtl"] 
-.form-item--editor-format .form-item__suffix {
-  margin-left: var(--sp0-5);
+  margin-inline-end: var(--sp0-5);
 }
 
 .form-item--editor-format .form-item__description,
diff --git a/core/themes/olivero/css/components/header-buttons-mobile.css b/core/themes/olivero/css/components/header-buttons-mobile.css
index 0d35d567742..2309a492a67 100644
--- a/core/themes/olivero/css/components/header-buttons-mobile.css
+++ b/core/themes/olivero/css/components/header-buttons-mobile.css
@@ -23,36 +23,29 @@
 
 /* Width of the entire grid maxes out. */
 
-[dir="ltr"] .mobile-buttons {
-  margin-left: auto;
-}
-
-[dir="rtl"] .mobile-buttons {
-  margin-right: auto;
-}
-
 .mobile-buttons {
-  margin-top: var(--sp0-5);
+  margin-block-start: var(--sp0-5);
+  margin-inline-start: auto;
 }
 
 @media (min-width: 31.25rem) {
 
 .mobile-buttons {
-    margin-top: var(--sp2);
+    margin-block-start: var(--sp2);
 }
   }
 
 @media (min-width: 43.75rem) {
 
 .mobile-buttons {
-    margin-top: var(--sp4);
+    margin-block-start: var(--sp4);
 }
   }
 
 @media (min-width: 75rem) {
 
 .mobile-buttons {
-    margin-top: var(--sp6);
+    margin-block-start: var(--sp6);
 }
   }
 
diff --git a/core/themes/olivero/css/components/header-navigation.css b/core/themes/olivero/css/components/header-navigation.css
index 578115024b8..c244338a919 100644
--- a/core/themes/olivero/css/components/header-navigation.css
+++ b/core/themes/olivero/css/components/header-navigation.css
@@ -23,34 +23,11 @@
 
 /* Width of the entire grid maxes out. */
 
-[dir="ltr"] .header-nav {
-  left: 100%;
-}
-
-[dir="rtl"] .header-nav {
-  right: 100%;
-}
-
-[dir="ltr"] .header-nav {
-  padding-left: var(--sp);
-}
-
-[dir="rtl"] .header-nav {
-  padding-right: var(--sp);
-}
-
-[dir="ltr"] .header-nav {
-  padding-right: var(--sp);
-}
-
-[dir="rtl"] .header-nav {
-  padding-left: var(--sp);
-}
-
 .header-nav {
   position: fixed;
   z-index: 501; /* Appear above overlay and contextual links in header. */
-  top: 0;
+  inset-block-start: 0;
+  inset-inline-start: 100%;
   visibility: hidden;
   overflow: auto;
   /* Ensure that header nav not use additional space and force system branding
@@ -59,13 +36,14 @@
   width: 100%;
   max-width: var(--mobile-nav-width);
   height: 100%;
-  padding-top: 0;
-  padding-bottom: var(--sp);
+  padding-block: 0 var(--sp);
+  padding-inline-start: var(--sp);
+  padding-inline-end: var(--sp);
   /* Create room for the "close" button. We cannot use margin because the
    * mobile navigation needs to slide beneath the button, but we also cannot
    * use padding because that would enable the button to scroll out of the
    * viewport on short screens. */
-  border-top: solid var(--color--white) calc(var(--sp3) + var(--drupal-displace-offset-top, 0px));
+  border-block-start: solid var(--color--white) calc(var(--sp3) + var(--drupal-displace-offset-top, 0px));
   background-color: var(--color--white);
   box-shadow: 0 0 72px rgba(0, 0, 0, 0.1);
 }
@@ -88,16 +66,9 @@
 
 @media (min-width: 43.75rem) {
 
-[dir="ltr"] .header-nav {
-    padding-left: var(--sp3);
-  }
-
-[dir="rtl"] .header-nav {
-    padding-right: var(--sp3);
-  }
-
 .header-nav {
-    padding-bottom: var(--sp3);
+    padding-block-end: var(--sp3);
+    padding-inline-start: var(--sp3);
     border-top-width: calc(var(--sp7) + var(--drupal-displace-offset-top, 0px));
 }
   }
@@ -131,22 +102,6 @@ html.js .header-nav {
 
 @media (min-width: 75rem) {
 
-[dir="ltr"] body:not(.is-always-mobile-nav) .header-nav {
-    padding-left: 0;
-  }
-
-[dir="rtl"] body:not(.is-always-mobile-nav) .header-nav {
-    padding-right: 0;
-  }
-
-[dir="ltr"] body:not(.is-always-mobile-nav) .header-nav {
-    padding-right: 0;
-  }
-
-[dir="rtl"] body:not(.is-always-mobile-nav) .header-nav {
-    padding-left: 0;
-  }
-
 body:not(.is-always-mobile-nav) .header-nav {
     position: static;
     display: flex;
@@ -157,29 +112,23 @@ body:not(.is-always-mobile-nav) .header-nav {
     justify-content: flex-end;
     max-width: none;
     height: var(--header-height-wide-when-fixed);
-    margin-top: auto;
-    padding-top: 0;
-    padding-bottom: 0;
+    margin-block-start: auto;
+    padding-block: 0;
+    padding-inline-start: 0;
+    padding-inline-end: 0;
     transition: transform 0.2s;
     transform: none;
-    border-top: 0;
+    border-block-start: 0;
     box-shadow: none;
 }
   }
 
 @media (min-width: 75rem) {
 
-[dir="ltr"] body.is-always-mobile-nav .header-nav {
-      padding-right: var(--sp);
-  }
-
-[dir="rtl"] body.is-always-mobile-nav .header-nav {
-      padding-left: var(--sp);
-  }
-
 body.is-always-mobile-nav .header-nav {
       overflow: auto;
       max-width: calc((7 * (var(--grid-col-width) + var(--grid-gap))));
+      padding-inline-end: var(--sp);
       transition: transform 0.2s, visibility 0.2s;
       border-top-width: calc(var(--drupal-displace-offset-top, 0px) + var(--sp11));
   }
@@ -187,31 +136,17 @@ body.is-always-mobile-nav .header-nav {
 
 @media (min-width: 90rem) {
 
-[dir="ltr"] body.is-always-mobile-nav .header-nav {
-      padding-right: calc(100vw - (var(--max-width) + var(--content-left) - var(--sp)));
-  }
-
-[dir="rtl"] body.is-always-mobile-nav .header-nav {
-      padding-left: calc(100vw - (var(--max-width) + var(--content-left) - var(--sp)));
-  }
-
 body.is-always-mobile-nav .header-nav {
       max-width: calc(100vw - (var(--max-width) + var(--content-left)) + ((7 * (var(--grid-col-width) + var(--grid-gap)))));
+      padding-inline-end: calc(100vw - (var(--max-width) + var(--content-left) - var(--sp)));
   }
     }
 
-[dir="ltr"] .header-nav-overlay {
-  left: 0;
-}
-
-[dir="rtl"] .header-nav-overlay {
-  right: 0;
-}
-
 .header-nav-overlay {
   position: fixed;
   z-index: 101;
-  top: 0;
+  inset-block-start: 0;
+  inset-inline-start: 0;
   display: none;
   width: 100%;
   height: 100vh;
diff --git a/core/themes/olivero/css/components/header-search-narrow.css b/core/themes/olivero/css/components/header-search-narrow.css
index ab1b1d4b192..3d160b4c59d 100644
--- a/core/themes/olivero/css/components/header-search-narrow.css
+++ b/core/themes/olivero/css/components/header-search-narrow.css
@@ -24,9 +24,8 @@
 /* Width of the entire grid maxes out. */
 
 .block-search-narrow {
-  margin-left: calc(-1 * var(--sp));
-  margin-right: calc(-1 * var(--sp));
-  margin-bottom: var(--sp2);
+  margin-inline: calc(-1 * var(--sp));
+  margin-block-end: var(--sp2);
   background: var(--color--black);
 }
 
@@ -43,27 +42,12 @@
     margin: 0;
   }
 
-[dir="ltr"] .block-search-narrow input[type="search"] {
-    padding-left: var(--sp);
-}
-
-[dir="rtl"] .block-search-narrow input[type="search"] {
-    padding-right: var(--sp);
-}
-
-[dir="ltr"] .block-search-narrow input[type="search"] {
-    padding-right: var(--sp);
-}
-
-[dir="rtl"] .block-search-narrow input[type="search"] {
-    padding-left: var(--sp);
-}
-
 .block-search-narrow input[type="search"] {
     width: calc(100% + var(--sp2));
     height: calc(3 * var(--sp));
-    padding-top: 0;
-    padding-bottom: 0;
+    padding-block: 0;
+    padding-inline-start: var(--sp);
+    padding-inline-end: var(--sp);
     transition: background-size 0.4s;
     color: var(--color--white);
     border: solid 1px transparent;
@@ -103,69 +87,25 @@
 
 @media (min-width: 43.75rem) {
 
-[dir="ltr"] .block-search-narrow input[type="search"] {
-      padding-left: var(--sp2);
-  }
-
-[dir="rtl"] .block-search-narrow input[type="search"] {
-      padding-right: var(--sp2);
-  }
-
-[dir="ltr"] .block-search-narrow input[type="search"] {
-      padding-right: var(--sp2);
-  }
-
-[dir="rtl"] .block-search-narrow input[type="search"] {
-      padding-left: var(--sp2);
-  }
-
 .block-search-narrow input[type="search"] {
       height: calc(4 * var(--sp));
+      padding-inline-start: var(--sp2);
+      padding-inline-end: var(--sp2);
   }
     }
 
-[dir="ltr"] .block-search-narrow .search-form__submit {
-    margin-left: 0;
-}
-
-[dir="rtl"] .block-search-narrow .search-form__submit {
-    margin-right: 0;
-}
-
-[dir="ltr"] .block-search-narrow .search-form__submit {
-    margin-right: 0;
-}
-
-[dir="rtl"] .block-search-narrow .search-form__submit {
-    margin-left: 0;
-}
-
-[dir="ltr"] .block-search-narrow .search-form__submit {
-    padding-left: 0;
-}
-
-[dir="rtl"] .block-search-narrow .search-form__submit {
-    padding-right: 0;
-}
-
-[dir="ltr"] .block-search-narrow .search-form__submit {
-    padding-right: 0;
-}
-
-[dir="rtl"] .block-search-narrow .search-form__submit {
-    padding-left: 0;
-}
-
 .block-search-narrow .search-form__submit {
     position: relative;
     overflow: hidden;
     align-self: stretch;
     width: var(--sp3);
     height: auto;
-    margin-top: 0;
-    margin-bottom: 0;
-    padding-top: 0;
-    padding-bottom: 0;
+    margin-block: 0;
+    margin-inline-start: 0;
+    margin-inline-end: 0;
+    padding-block: 0;
+    padding-inline-start: 0;
+    padding-inline-end: 0;
     cursor: pointer;
     border-color: transparent;
     background-color: transparent;
@@ -176,17 +116,10 @@
     */
   }
 
-[dir="ltr"] .block-search-narrow .search-form__submit .icon--search {
-      left: 0;
-}
-
-[dir="rtl"] .block-search-narrow .search-form__submit .icon--search {
-      right: 0;
-}
-
 .block-search-narrow .search-form__submit .icon--search {
       position: absolute;
-      top: 0;
+      inset-block-start: 0;
+      inset-inline-start: 0;
       display: block;
       width: 100%; /* Width of the SVG background image. */
       height: 100%;
@@ -197,24 +130,17 @@
       background-size: auto;
     }
 
-[dir="ltr"] .block-search-narrow .search-form__submit .icon--search:after {
-        left: 0;
-}
-
-[dir="rtl"] .block-search-narrow .search-form__submit .icon--search:after {
-        right: 0;
-}
-
 .block-search-narrow .search-form__submit .icon--search:after {
         position: absolute;
-        bottom: 0;
+        inset-block-end: 0;
+        inset-inline-start: 0;
         width: 100%;
         height: 0;
         content: "";
         transition: transform 0.2s;
         transform: scaleX(0);
         transform-origin: left; /* LTR */
-        border-top: solid 0.3125rem var(--color--primary-50);
+        border-block-start: solid 0.3125rem var(--color--primary-50);
       }
 
 @media (forced-colors: active) {
@@ -279,21 +205,10 @@
 
 @media (min-width: 31.25rem) {
 
-[dir="ltr"] .block-search-narrow {
-    margin-left: 0;
-  }
-
-[dir="rtl"] .block-search-narrow {
-    margin-right: 0;
-  }
-
-[dir="ltr"] .block-search-narrow {
-    margin-right: 0;
-  }
-
-[dir="rtl"] .block-search-narrow {
-    margin-left: 0;
-  }
+.block-search-narrow {
+    margin-inline-start: 0;
+    margin-inline-end: 0;
+}
   }
 
 @media (min-width: 75rem) {
diff --git a/core/themes/olivero/css/components/header-search-wide.css b/core/themes/olivero/css/components/header-search-wide.css
index 3000fe9583b..768c2f95922 100644
--- a/core/themes/olivero/css/components/header-search-wide.css
+++ b/core/themes/olivero/css/components/header-search-wide.css
@@ -29,58 +29,11 @@
   position: static;
 }
 
-[dir="ltr"] .block-search-wide__wrapper {
-  left: 0;
-}
-
-[dir="rtl"] .block-search-wide__wrapper {
-  right: 0;
-}
-
-[dir="ltr"] .block-search-wide__wrapper {
-  margin-left: 0;
-}
-
-[dir="rtl"] .block-search-wide__wrapper {
-  margin-right: 0;
-}
-
-[dir="ltr"] .block-search-wide__wrapper {
-  margin-right: 0;
-}
-
-[dir="rtl"] .block-search-wide__wrapper {
-  margin-left: 0;
-}
-
-[dir="ltr"] .block-search-wide__wrapper {
-  padding-left: 0;
-}
-
-[dir="rtl"] .block-search-wide__wrapper {
-  padding-right: 0;
-}
-
-[dir="ltr"] .block-search-wide__wrapper {
-  padding-right: 0;
-}
-
-[dir="rtl"] .block-search-wide__wrapper {
-  padding-left: 0;
-}
-
-[dir="ltr"] .block-search-wide__wrapper {
-  border-left: solid var(--content-left) var(--color--gray-20);
-}
-
-[dir="rtl"] .block-search-wide__wrapper {
-  border-right: solid var(--content-left) var(--color--gray-20);
-}
-
 .block-search-wide__wrapper {
   position: absolute;
   z-index: 1; /* Ensure left border shows above social region in IE11. */
-  top: 100%;
+  inset-block-start: 100%;
+  inset-inline-start: 0;
   display: none;
   visibility: hidden;
   overflow: hidden;
@@ -88,11 +41,14 @@
   max-width: var(--max-bg-color);
   height: var(--sp8);
   max-height: 0;
-  margin-top: 0;
-  margin-bottom: 0;
-  padding-top: 0;
-  padding-bottom: 0;
+  margin-block: 0;
+  margin-inline-start: 0;
+  margin-inline-end: 0;
+  padding-block: 0;
+  padding-inline-start: 0;
+  padding-inline-end: 0;
   transition: all 0.2s;
+  border-inline-start: solid var(--content-left) var(--color--gray-20);
   background: var(--color--black);
 }
 
@@ -106,27 +62,12 @@
     grid-column: 1 / 14;
   }
 
-[dir="ltr"] .block-search-wide__wrapper input[type="search"] {
-    padding-left: var(--sp12);
-}
-
-[dir="rtl"] .block-search-wide__wrapper input[type="search"] {
-    padding-right: var(--sp12);
-}
-
-[dir="ltr"] .block-search-wide__wrapper input[type="search"] {
-    padding-right: 0;
-}
-
-[dir="rtl"] .block-search-wide__wrapper input[type="search"] {
-    padding-left: 0;
-}
-
 .block-search-wide__wrapper input[type="search"] {
     width: calc(100% + var(--sp2));
     height: var(--sp8);
-    padding-top: 0;
-    padding-bottom: 0;
+    padding-block: 0;
+    padding-inline-start: var(--sp12);
+    padding-inline-end: 0;
     transition: background-size 0.4s;
     color: var(--color--white);
     border: solid 1px transparent;
@@ -168,48 +109,18 @@
     margin: 0;
   }
 
-[dir="ltr"] .block-search-wide__wrapper .search-form__submit {
-    margin-left: 0;
-}
-
-[dir="rtl"] .block-search-wide__wrapper .search-form__submit {
-    margin-right: 0;
-}
-
-[dir="ltr"] .block-search-wide__wrapper .search-form__submit {
-    margin-right: 0;
-}
-
-[dir="rtl"] .block-search-wide__wrapper .search-form__submit {
-    margin-left: 0;
-}
-
-[dir="ltr"] .block-search-wide__wrapper .search-form__submit {
-    padding-left: 0;
-}
-
-[dir="rtl"] .block-search-wide__wrapper .search-form__submit {
-    padding-right: 0;
-}
-
-[dir="ltr"] .block-search-wide__wrapper .search-form__submit {
-    padding-right: 0;
-}
-
-[dir="rtl"] .block-search-wide__wrapper .search-form__submit {
-    padding-left: 0;
-}
-
 .block-search-wide__wrapper .search-form__submit {
     position: relative;
     overflow: hidden;
     align-self: stretch;
     width: 6.25rem;
     height: auto;
-    margin-top: 0;
-    margin-bottom: 0;
-    padding-top: 0;
-    padding-bottom: 0;
+    margin-block: 0;
+    margin-inline-start: 0;
+    margin-inline-end: 0;
+    padding-block: 0;
+    padding-inline-start: 0;
+    padding-inline-end: 0;
     cursor: pointer;
     border-color: transparent;
     background-color: transparent;
@@ -220,17 +131,10 @@
     */
   }
 
-[dir="ltr"] .block-search-wide__wrapper .search-form__submit .icon--search {
-      right: 0;
-}
-
-[dir="rtl"] .block-search-wide__wrapper .search-form__submit .icon--search {
-      left: 0;
-}
-
 .block-search-wide__wrapper .search-form__submit .icon--search {
       position: absolute;
-      top: 0;
+      inset-block-start: 0;
+      inset-inline-end: 0;
       display: block;
       width: 1.5rem; /* Width of the SVG background image. */
       height: 100%;
@@ -241,24 +145,17 @@
       background-size: contain;
     }
 
-[dir="ltr"] .block-search-wide__wrapper .search-form__submit .icon--search:after {
-        left: 0;
-}
-
-[dir="rtl"] .block-search-wide__wrapper .search-form__submit .icon--search:after {
-        right: 0;
-}
-
 .block-search-wide__wrapper .search-form__submit .icon--search:after {
         position: absolute;
-        bottom: 0;
+        inset-block-end: 0;
+        inset-inline-start: 0;
         width: 100%;
         height: 0;
         content: "";
         transition: transform 0.2s;
         transform: scaleX(0);
         transform-origin: left;
-        border-top: solid var(--sp0-5) var(--color--primary-50);
+        border-block-start: solid var(--sp0-5) var(--color--primary-50);
       }
 
 .block-search-wide__wrapper .search-form__submit:focus {
@@ -299,16 +196,9 @@
       }
     }
 
-[dir="ltr"] .block-search-wide__container {
-  padding-right: var(--sp2);
-}
-
-[dir="rtl"] .block-search-wide__container {
-  padding-left: var(--sp2);
-}
-
 .block-search-wide__container {
   max-width: var(--max-width);
+  padding-inline-end: var(--sp2);
 }
 
 .block-search-wide__grid {
@@ -372,7 +262,7 @@
         width: var(--sp1-5);
         height: 0;
         content: "";
-        border-top: solid 2px var(--color--white);
+        border-block-start: solid 2px var(--color--white);
       }
 
 .block-search-wide__button[aria-expanded="true"] .block-search-wide__button-close:before {
@@ -387,21 +277,10 @@
       display: none;
     }
 
-[dir="ltr"] .block-search-wide__button svg {
-    margin-left: auto;
-}
-
-[dir="rtl"] .block-search-wide__button svg {
-    margin-right: auto;
-}
-
-[dir="ltr"] .block-search-wide__button svg {
-    margin-right: auto;
-}
-
-[dir="rtl"] .block-search-wide__button svg {
-    margin-left: auto;
-}
+.block-search-wide__button svg {
+    margin-inline-start: auto;
+    margin-inline-end: auto;
+  }
 
 @media (forced-colors: active) {
 
diff --git a/core/themes/olivero/css/components/header-site-branding.css b/core/themes/olivero/css/components/header-site-branding.css
index e87024f87dd..42b86c2a83f 100644
--- a/core/themes/olivero/css/components/header-site-branding.css
+++ b/core/themes/olivero/css/components/header-site-branding.css
@@ -23,40 +23,16 @@
 
 /* Width of the entire grid maxes out. */
 
-[dir="ltr"] .site-branding {
-  margin-left: calc(-1 * var(--container-padding));
-  margin-right: var(--sp);
-}
-
-[dir="rtl"] .site-branding {
-  margin-right: calc(-1 * var(--container-padding));
-  margin-left: var(--sp);
-}
-
-[dir="ltr"] .site-branding {
-  padding-left: var(--container-padding);
-}
-
-[dir="rtl"] .site-branding {
-  padding-right: var(--container-padding);
-}
-
-[dir="ltr"] .site-branding {
-  padding-right: var(--container-padding);
-}
-
-[dir="rtl"] .site-branding {
-  padding-left: var(--container-padding);
-}
-
 .site-branding {
   display: flex;
   flex-shrink: 1;
   align-items: flex-end;
   min-width: calc((2 * var(--grid-col-width)) + (2 * var(--grid-gap)) + var(--container-padding)); /* Span minimum of 2 column widths. */
-  min-height: var(--sp3); /* Negative margin to break out of .container element. */
-  padding-top: 0;
-  padding-bottom: var(--sp0-5);
+  min-height: var(--sp3);
+  margin-inline: calc(-1 * var(--container-padding)) var(--sp); /* Negative margin to break out of .container element. */
+  padding-block: 0 var(--sp0-5);
+  padding-inline-start: var(--container-padding);
+  padding-inline-end: var(--container-padding);
   background-image: linear-gradient(160deg, var(--color--primary-50) 0%, var(--color--primary-40) 78.66%);
 }
 
@@ -72,7 +48,7 @@
 .site-branding {
     min-width: calc((4 * var(--grid-col-width)) + (4 * var(--grid-gap)) + var(--container-padding)); /* Span minimum of 4 column widths. */
     min-height: var(--sp6);
-    padding-bottom: var(--sp);
+    padding-block-end: var(--sp);
 }
   }
 
@@ -85,18 +61,10 @@
 
 @media (min-width: 75rem) {
 
-[dir="ltr"] .site-branding {
-    margin-left: calc(-1 * var(--container-padding));
-  }
-
-[dir="rtl"] .site-branding {
-    margin-right: calc(-1 * var(--container-padding));
-  }
-
 .site-branding {
     min-height: var(--site-header-height-wide);
-    padding-top: 0;
-    padding-bottom: 0;
+    margin-inline-start: calc(-1 * var(--container-padding));
+    padding-block: 0;
 }
   }
 
@@ -123,26 +91,11 @@
 
 @media (min-width: 75rem) {
 
-[dir="ltr"] .site-branding__inner {
-    padding-left: 0;
-  }
-
-[dir="rtl"] .site-branding__inner {
-    padding-right: 0;
-  }
-
-[dir="ltr"] .site-branding__inner {
-    padding-right: 0;
-  }
-
-[dir="rtl"] .site-branding__inner {
-    padding-left: 0;
-  }
-
 .site-branding__inner {
     height: var(--header-height-wide-when-fixed);
-    padding-top: var(--sp0-5);
-    padding-bottom: var(--sp0-5);
+    padding-block: var(--sp0-5);
+    padding-inline-start: 0;
+    padding-inline-end: 0;
 }
   }
 
@@ -210,10 +163,6 @@
   color: var(--color--primary-50);
 }
 
-[dir="ltr"] .site-branding__logo + .site-branding__text {
-  margin-left: 0.75rem;
-}
-
-[dir="rtl"] .site-branding__logo + .site-branding__text {
-  margin-right: 0.75rem;
+.site-branding__logo + .site-branding__text {
+  margin-inline-start: 0.75rem;
 }
diff --git a/core/themes/olivero/css/components/header-sticky-toggle.css b/core/themes/olivero/css/components/header-sticky-toggle.css
index 9901633dfba..40c9d1b1ebf 100644
--- a/core/themes/olivero/css/components/header-sticky-toggle.css
+++ b/core/themes/olivero/css/components/header-sticky-toggle.css
@@ -85,52 +85,30 @@ body.is-always-mobile-nav .sticky-header-toggle {
     border-top: solid 3px var(--color--white);
   }
 
-[dir="ltr"] .sticky-header-toggle__icon > span:nth-child(1) {
-      left: 0;
-}
-
-[dir="rtl"] .sticky-header-toggle__icon > span:nth-child(1) {
-      right: 0;
-}
-
 .sticky-header-toggle__icon > span:nth-child(1) {
       position: absolute;
-      top: 0;
+      inset-block-start: 0;
+      inset-inline-start: 0;
       width: 100%;
       height: 0;
       transition: transform 0.2s;
       background-color: var(--color--white);
     }
 
-[dir="ltr"] .sticky-header-toggle__icon > span:nth-child(2) {
-      left: 0;
-}
-
-[dir="rtl"] .sticky-header-toggle__icon > span:nth-child(2) {
-      right: 0;
-}
-
 .sticky-header-toggle__icon > span:nth-child(2) {
       position: absolute;
-      top: 0.5625rem;
+      inset-block-start: 0.5625rem;
+      inset-inline-start: 0;
       width: 100%;
       height: 0;
       transition: opacity 0.2s;
       background-color: var(--color--white);
     }
 
-[dir="ltr"] .sticky-header-toggle__icon > span:nth-child(3) {
-      left: 0;
-}
-
-[dir="rtl"] .sticky-header-toggle__icon > span:nth-child(3) {
-      right: 0;
-}
-
 .sticky-header-toggle__icon > span:nth-child(3) {
       position: absolute;
-      top: auto;
-      bottom: 0;
+      inset-block: auto 0;
+      inset-inline-start: 0;
       width: 100%;
       height: 0;
       transition: transform 0.2s;
@@ -144,7 +122,7 @@ body.is-always-mobile-nav .sticky-header-toggle {
 }
 
 [aria-checked="true"] .sticky-header-toggle__icon > span:nth-child(1) {
-    top: 0.5625rem;
+    inset-block-start: 0.5625rem;
     transform: rotate(-45deg);
   }
 
@@ -153,6 +131,6 @@ body.is-always-mobile-nav .sticky-header-toggle {
   }
 
 [aria-checked="true"] .sticky-header-toggle__icon > span:nth-child(3) {
-    top: 0.5625rem;
+    inset-block-start: 0.5625rem;
     transform: rotate(45deg);
   }
diff --git a/core/themes/olivero/css/components/hero.css b/core/themes/olivero/css/components/hero.css
index ca4ed3daa26..3e084a404ef 100644
--- a/core/themes/olivero/css/components/hero.css
+++ b/core/themes/olivero/css/components/hero.css
@@ -43,8 +43,8 @@
 
 .hero__img {
   grid-column: 1 / 7;
-  margin-top: var(--sp2);
-  margin-bottom: var(--sp2);
+  margin-block-start: var(--sp2);
+  margin-block-end: var(--sp2);
 }
 
 .hero__img img {
@@ -54,8 +54,8 @@
 @media (min-width: 31.25rem) {
 
 .hero__img {
-    margin-top: var(--sp3);
-    margin-bottom: var(--sp3);
+    margin-block-start: var(--sp3);
+    margin-block-end: var(--sp3);
 }
   }
 
@@ -63,8 +63,8 @@
 
 .hero__img {
     grid-column: 1 / 15;
-    margin-top: var(--sp4);
-    margin-bottom: var(--sp4);
+    margin-block-start: var(--sp4);
+    margin-block-end: var(--sp4);
 }
   }
 
diff --git a/core/themes/olivero/css/components/links.css b/core/themes/olivero/css/components/links.css
index 30d4efd84f9..3006bcbfbd7 100644
--- a/core/themes/olivero/css/components/links.css
+++ b/core/themes/olivero/css/components/links.css
@@ -23,33 +23,11 @@
 
 /* Width of the entire grid maxes out. */
 
-[dir="ltr"] .links.inline {
-  margin-left: 0;
-}
-
-[dir="rtl"] .links.inline {
-  margin-right: 0;
-}
-
-[dir="ltr"] .links.inline {
-  padding-left: 0;
-}
-
-[dir="rtl"] .links.inline {
-  padding-right: 0;
-}
-
-[dir="ltr"] .links.inline {
-  padding-right: 0;
-}
-
-[dir="rtl"] .links.inline {
-  padding-left: 0;
-}
-
 .links.inline {
-  padding-top: 0;
-  padding-bottom: 0;
+  margin-inline-start: 0;
+  padding-block: 0;
+  padding-inline-start: 0;
+  padding-inline-end: 0;
   list-style: none;
 }
 
@@ -57,21 +35,13 @@
     display: inline;
   }
 
-[dir="ltr"] .links.inline > *:not(:last-child) {
-      padding-right: 1em;
-}
-
-[dir="rtl"] .links.inline > *:not(:last-child) {
-      padding-left: 1em;
-}
+.links.inline > *:not(:last-child) {
+      padding-inline-end: 1em;
+    }
 
 @media (min-width: 43.75rem) {
 
-[dir="ltr"] .node--type-book .links.inline {
-    text-align: right;
-  }
-
-[dir="rtl"] .node--type-book .links.inline {
-    text-align: left;
-  }
+.node--type-book .links.inline {
+    text-align: end;
+}
   }
diff --git a/core/themes/olivero/css/components/maintenance-page.css b/core/themes/olivero/css/components/maintenance-page.css
index fa385f38fd5..5c9e213aef4 100644
--- a/core/themes/olivero/css/components/maintenance-page.css
+++ b/core/themes/olivero/css/components/maintenance-page.css
@@ -37,8 +37,7 @@
 
 .maintenance-page-icon {
   display: block;
-  margin-top: var(--sp3);
-  margin-bottom: var(--sp3);
+  margin-block: var(--sp3);
 }
 
 .maintenance-page-icon path {
diff --git a/core/themes/olivero/css/components/messages.css b/core/themes/olivero/css/components/messages.css
index e5b24f83bd7..b362509d1e7 100644
--- a/core/themes/olivero/css/components/messages.css
+++ b/core/themes/olivero/css/components/messages.css
@@ -27,50 +27,19 @@
   --messages-icon-size: 2rem;
 }
 
-[dir="ltr"] .messages-list {
-  padding-left: 0;
-}
-
-[dir="rtl"] .messages-list {
-  padding-right: 0;
-}
-
-[dir="ltr"] .messages-list {
-  padding-right: 0;
-}
-
-[dir="rtl"] .messages-list {
-  padding-left: 0;
-}
-
 .messages-list {
-  margin-top: var(--sp1);
-  margin-bottom: var(--sp1);
-  padding-top: 0;
-  padding-bottom: 0;
+  margin-block: var(--sp1);
+  padding-block: 0;
+  padding-inline-start: 0;
+  padding-inline-end: 0;
   list-style: none;
 }
 
-[dir="ltr"] .messages {
-  padding-left: var(--sp1-5);
-}
-
-[dir="rtl"] .messages {
-  padding-right: var(--sp1-5);
-}
-
-[dir="ltr"] .messages {
-  padding-right: var(--sp1-5);
-}
-
-[dir="rtl"] .messages {
-  padding-left: var(--sp1-5);
-}
-
 .messages {
   min-height: calc(var(--messages-icon-size) + 2 * var(--sp1));
-  padding-top: var(--sp1);
-  padding-bottom: var(--sp1);
+  padding-block: var(--sp1);
+  padding-inline-start: var(--sp1-5);
+  padding-inline-end: var(--sp1-5);
   color: var(--color--white);
   outline: solid 1px transparent;
   background-color: var(--color--gray-5);
@@ -86,119 +55,56 @@
     background-image: none;
   }
 
-[dir="ltr"] .messages__list {
-  margin-left: 0;
-}
-
-[dir="rtl"] .messages__list {
-  margin-right: 0;
-}
-
-[dir="ltr"] .messages__list {
-  margin-right: 0;
-}
-
-[dir="rtl"] .messages__list {
-  margin-left: 0;
-}
-
-[dir="ltr"] .messages__list {
-  padding-left: 0;
-}
-
-[dir="rtl"] .messages__list {
-  padding-right: 0;
-}
-
-[dir="ltr"] .messages__list {
-  padding-right: 0;
-}
-
-[dir="rtl"] .messages__list {
-  padding-left: 0;
-}
-
 .messages__list {
-  margin-top: 0;
-  margin-bottom: 0;
-  padding-top: 0;
-  padding-bottom: 0;
+  margin-block: 0;
+  margin-inline-start: 0;
+  margin-inline-end: 0;
+  padding-block: 0;
+  padding-inline-start: 0;
+  padding-inline-end: 0;
   list-style: none;
 }
 
 .messages:not(.hidden) ~ .messages {
-  margin-top: var(--sp1);
+  margin-block-start: var(--sp1);
 }
 
 .messages__item + .messages__item {
-  margin-top: var(--sp0-5);
+  margin-block-start: var(--sp0-5);
 }
 
 .messages__container {
   display: flex;
 }
 
-[dir="ltr"] .messages__header {
-  margin-right: var(--sp1);
-}
-
-[dir="rtl"] .messages__header {
-  margin-left: var(--sp1);
-}
-
 .messages__header {
   flex-shrink: 0;
+  margin-inline-end: var(--sp1);
 }
 
-[dir="ltr"] .messages__header.no-icon {
-    margin-right: 0;
-}
-
-[dir="rtl"] .messages__header.no-icon {
-    margin-left: 0;
-}
+.messages__header.no-icon {
+    margin-inline-end: 0;
+  }
 
 .messages__content {
   overflow: auto; /* Ensure large code blocks can be scrolled to. */
   flex: 1;
-  padding-top: 0.1875rem;
-}
-
-[dir="ltr"] .messages__button {
-  margin-left: var(--sp1);
-}
-
-[dir="rtl"] .messages__button {
-  margin-right: var(--sp1);
+  padding-block-start: 0.1875rem;
 }
 
 .messages__button {
   flex-shrink: 0;
-  padding-top: 0.1875rem;
-}
-
-[dir="ltr"] .messages__close {
-  padding-left: 0;
-}
-
-[dir="rtl"] .messages__close {
-  padding-right: 0;
-}
-
-[dir="ltr"] .messages__close {
-  padding-right: 0;
-}
-
-[dir="rtl"] .messages__close {
-  padding-left: 0;
+  margin-inline-start: var(--sp1);
+  padding-block-start: 0.1875rem;
 }
 
 .messages__close {
   position: relative;
   width: 1.5625rem;
   height: 1.5625rem;
-  padding-top: 0;
-  padding-bottom: 0;
+  padding-block: 0;
+  padding-inline-start: 0;
+  padding-inline-end: 0;
   cursor: pointer;
   vertical-align: top;
   border: 0;
@@ -265,14 +171,7 @@
   margin: 0;
 }
 
-[dir="ltr"] .js-form-managed-file .messages {
-  border-left: solid 0.375rem var(--color--red);
-}
-
-[dir="rtl"] .js-form-managed-file .messages {
-  border-right: solid 0.375rem var(--color--red);
-}
-
 .js-form-managed-file .messages {
-  margin-bottom: var(--sp1);
+  margin-block-end: var(--sp1);
+  border-inline-start: solid 0.375rem var(--color--red);
 }
diff --git a/core/themes/olivero/css/components/navigation/menu-sidebar.css b/core/themes/olivero/css/components/navigation/menu-sidebar.css
index 6611024408b..313169b65c2 100644
--- a/core/themes/olivero/css/components/navigation/menu-sidebar.css
+++ b/core/themes/olivero/css/components/navigation/menu-sidebar.css
@@ -35,48 +35,26 @@
     margin: 0;
   }
 
-[dir="ltr"] .menu--sidebar .menu__link {
-    padding-left: 0;
-}
-
-[dir="rtl"] .menu--sidebar .menu__link {
-    padding-right: 0;
-}
-
-[dir="ltr"] .menu--sidebar .menu__link {
-    padding-right: 0;
-}
-
-[dir="rtl"] .menu--sidebar .menu__link {
-    padding-left: 0;
-}
-
 .menu--sidebar .menu__link {
     position: relative;
     display: block;
-    padding-top: var(--sp0-75);
-    padding-bottom: var(--sp0-75);
+    padding-block: var(--sp0-75);
+    padding-inline-start: 0;
+    padding-inline-end: 0;
     font-family: var(--font-serif);
     font-size: 1.125rem;
 
     /* Bottom divider line. */
   }
 
-[dir="ltr"] .menu--sidebar .menu__link:after {
-      left: 0;
-}
-
-[dir="rtl"] .menu--sidebar .menu__link:after {
-      right: 0;
-}
-
 .menu--sidebar .menu__link:after {
       position: absolute;
-      bottom: 0;
+      inset-block-end: 0;
+      inset-inline-start: 0;
       width: var(--sp4);
       height: 0;
       content: "";
-      border-top: solid 2px var(--color--gray-95);
+      border-block-start: solid 2px var(--color--gray-95);
     }
 
 .menu--sidebar .menu__link--link {
diff --git a/core/themes/olivero/css/components/navigation/nav-button-mobile.css b/core/themes/olivero/css/components/navigation/nav-button-mobile.css
index 9171144c077..cb6a70c5ef6 100644
--- a/core/themes/olivero/css/components/navigation/nav-button-mobile.css
+++ b/core/themes/olivero/css/components/navigation/nav-button-mobile.css
@@ -23,38 +23,6 @@
 
 /* Width of the entire grid maxes out. */
 
-[dir="ltr"] .mobile-nav-button {
-  margin-left: auto;
-}
-
-[dir="rtl"] .mobile-nav-button {
-  margin-right: auto;
-}
-
-[dir="ltr"] .mobile-nav-button {
-  margin-right: -0.375rem;
-}
-
-[dir="rtl"] .mobile-nav-button {
-  margin-left: -0.375rem;
-}
-
-[dir="ltr"] .mobile-nav-button {
-  padding-left: 0.375rem;
-}
-
-[dir="rtl"] .mobile-nav-button {
-  padding-right: 0.375rem;
-}
-
-[dir="ltr"] .mobile-nav-button {
-  padding-right: 0.375rem;
-}
-
-[dir="rtl"] .mobile-nav-button {
-  padding-left: 0.375rem;
-}
-
 .mobile-nav-button {
   position: relative;
   z-index: 505; /* Appear above mobile nav. */
@@ -63,8 +31,11 @@
   align-self: center;
   width: var(--sp2);
   height: var(--sp2);
-  padding-top: 0;
-  padding-bottom: 0;
+  margin-inline-start: auto;
+  margin-inline-end: -0.375rem;
+  padding-block: 0;
+  padding-inline-start: 0.375rem;
+  padding-inline-end: 0.375rem;
   cursor: pointer;
   border: none;
   background: transparent;
@@ -82,17 +53,10 @@
 
 @media (min-width: 31.25rem) {
 
-[dir="ltr"] .mobile-nav-button {
-    padding-left: var(--sp);
-  }
-
-[dir="rtl"] .mobile-nav-button {
-    padding-right: var(--sp);
-  }
-
 .mobile-nav-button {
     display: inline-flex;
     width: auto;
+    padding-inline-start: var(--sp);
 }
   }
 
@@ -110,20 +74,13 @@
 
 @media (min-width: 31.25rem) {
 
-[dir="ltr"] .mobile-nav-button__label {
-    margin-right: 0.75rem;
-  }
-
-[dir="rtl"] .mobile-nav-button__label {
-    margin-left: 0.75rem;
-  }
-
 .mobile-nav-button__label {
     position: static;
     overflow: visible;
     clip: auto;
     width: auto;
     height: auto;
+    margin-inline-end: 0.75rem;
     letter-spacing: 0.05em;
     font-size: 0.875rem;
     font-weight: 600;
@@ -138,17 +95,10 @@
   border-top: solid 3px var(--color--primary-50);
 }
 
-[dir="ltr"] .mobile-nav-button__icon:before {
-    left: 0;
-}
-
-[dir="rtl"] .mobile-nav-button__icon:before {
-    right: 0;
-}
-
 .mobile-nav-button__icon:before {
     position: absolute;
-    top: -0.6875rem;
+    inset-block-start: -0.6875rem;
+    inset-inline-start: 0;
     width: 100%;
     height: 0;
     content: "";
@@ -156,18 +106,10 @@
     border-top: solid 3px var(--color--primary-50);
   }
 
-[dir="ltr"] .mobile-nav-button__icon:after {
-    left: 0;
-}
-
-[dir="rtl"] .mobile-nav-button__icon:after {
-    right: 0;
-}
-
 .mobile-nav-button__icon:after {
     position: absolute;
-    top: auto;
-    bottom: -0.5rem;
+    inset-block: auto -0.5rem;
+    inset-inline-start: 0;
     width: 100%;
     height: 0;
     content: "";
@@ -180,11 +122,11 @@
 }
 
 .mobile-nav-button[aria-expanded="true"] .mobile-nav-button__icon:before {
-    top: 0;
+    inset-block-start: 0;
     transform: rotate(-45deg);
   }
 
 .mobile-nav-button[aria-expanded="true"] .mobile-nav-button__icon:after {
-    top: 0;
+    inset-block-start: 0;
     transform: rotate(45deg);
   }
diff --git a/core/themes/olivero/css/components/navigation/nav-primary-button.css b/core/themes/olivero/css/components/navigation/nav-primary-button.css
index c62a138b447..462752f685a 100644
--- a/core/themes/olivero/css/components/navigation/nav-primary-button.css
+++ b/core/themes/olivero/css/components/navigation/nav-primary-button.css
@@ -23,30 +23,15 @@
 
 /* Width of the entire grid maxes out. */
 
-[dir="ltr"] .primary-nav__button-toggle {
-  padding-left: 0;
-}
-
-[dir="rtl"] .primary-nav__button-toggle {
-  padding-right: 0;
-}
-
-[dir="ltr"] .primary-nav__button-toggle {
-  padding-right: 0;
-}
-
-[dir="rtl"] .primary-nav__button-toggle {
-  padding-left: 0;
-}
-
 .primary-nav__button-toggle {
   position: relative;
   overflow: hidden;
   width: var(--sp2);
   height: var(--sp2);
-  margin-top: var(--sp0-5); /* Visually align button with menu link text. */
-  padding-top: 0;
-  padding-bottom: 0;
+  margin-block-start: var(--sp0-5); /* Visually align button with menu link text. */
+  padding-block: 0;
+  padding-inline-start: 0;
+  padding-inline-end: 0;
   cursor: pointer;
   text-indent: -62.4375rem;
   border: 0;
@@ -105,18 +90,13 @@
   }
 
 @media (min-width: 75rem) {
-    [dir="ltr"] body:not(.is-always-mobile-nav) .primary-nav__button-toggle {
-      margin-right: calc(-1 * var(--sp2));
-  }
-    [dir="rtl"] body:not(.is-always-mobile-nav) .primary-nav__button-toggle {
-      margin-left: calc(-1 * var(--sp2));
-  }
     body:not(.is-always-mobile-nav) .primary-nav__button-toggle {
       flex-shrink: 0;
       align-self: stretch;
       width: calc(var(--sp2) + 0.5rem);
       height: auto;
-      margin-top: 0;
+      margin-block-start: 0;
+      margin-inline-end: calc(-1 * var(--sp2));
     }
 
       body:not(.is-always-mobile-nav) .primary-nav__button-toggle:focus {
@@ -137,15 +117,8 @@
         opacity: 0.8;
       }
 
-      [dir="ltr"] body:not(.is-always-mobile-nav) .primary-nav__button-toggle .icon--menu-toggle {
-        left: 0.1875rem;
-  }
-
-      [dir="rtl"] body:not(.is-always-mobile-nav) .primary-nav__button-toggle .icon--menu-toggle {
-        right: 0.1875rem;
-  }
-
       body:not(.is-always-mobile-nav) .primary-nav__button-toggle .icon--menu-toggle {
+        inset-inline-start: 0.1875rem;
         width: 1.125rem;
         transform: translateY(-50%);
         border-radius: 0.25rem;
diff --git a/core/themes/olivero/css/components/navigation/nav-primary-no-js.css b/core/themes/olivero/css/components/navigation/nav-primary-no-js.css
index 7ad38c9cd32..f4a108bc031 100644
--- a/core/themes/olivero/css/components/navigation/nav-primary-no-js.css
+++ b/core/themes/olivero/css/components/navigation/nav-primary-no-js.css
@@ -51,38 +51,6 @@
       display: none;
     }
 
-    html[dir="ltr"]:not(.js) .header-nav {
-      margin-left: var(--sp2);
-  }
-
-    html[dir="rtl"]:not(.js) .header-nav {
-      margin-right: var(--sp2);
-  }
-
-    html[dir="ltr"]:not(.js) .header-nav {
-      margin-right: var(--sp2);
-  }
-
-    html[dir="rtl"]:not(.js) .header-nav {
-      margin-left: var(--sp2);
-  }
-
-    html[dir="ltr"]:not(.js) .header-nav {
-      padding-left: var(--sp2);
-  }
-
-    html[dir="rtl"]:not(.js) .header-nav {
-      padding-right: var(--sp2);
-  }
-
-    html[dir="ltr"]:not(.js) .header-nav {
-      padding-right: var(--sp2);
-  }
-
-    html[dir="rtl"]:not(.js) .header-nav {
-      padding-left: var(--sp2);
-  }
-
     html:not(.js) .header-nav {
       border: solid 1px var(--color--gray-95) !important;
     }
@@ -93,21 +61,19 @@
       flex-basis: 100%;
       width: 100%;
       max-width: none;
-      margin-top: var(--sp2);
-      margin-bottom: 0;
-      padding-top: var(--sp2);
-      padding-bottom: 0;
+      margin-block: var(--sp2) 0;
+      margin-inline-start: var(--sp2);
+      margin-inline-end: var(--sp2);
+      padding-block: var(--sp2) 0;
+      padding-inline-start: var(--sp2);
+      padding-inline-end: var(--sp2);
       transform: none;
       box-shadow: 0 0 36px var(--color--gray-90);
     }
 
-    html[dir="ltr"]:not(.js) .primary-nav__menu--level-2 {
-      border-left: 0;
-  }
-
-    html[dir="rtl"]:not(.js) .primary-nav__menu--level-2 {
-      border-right: 0;
-  }
+    html:not(.js) .primary-nav__menu--level-2 {
+      border-inline-start: 0;
+    }
 
     html:not(.js) .primary-nav__button-toggle {
       display: none;
@@ -140,38 +106,6 @@
         display: none;
       }
 
-      html[dir="ltr"]:not(.js) body.is-always-mobile-nav .header-nav {
-        margin-left: var(--sp2);
-  }
-
-      html[dir="rtl"]:not(.js) body.is-always-mobile-nav .header-nav {
-        margin-right: var(--sp2);
-  }
-
-      html[dir="ltr"]:not(.js) body.is-always-mobile-nav .header-nav {
-        margin-right: var(--sp2);
-  }
-
-      html[dir="rtl"]:not(.js) body.is-always-mobile-nav .header-nav {
-        margin-left: var(--sp2);
-  }
-
-      html[dir="ltr"]:not(.js) body.is-always-mobile-nav .header-nav {
-        padding-left: var(--sp2);
-  }
-
-      html[dir="rtl"]:not(.js) body.is-always-mobile-nav .header-nav {
-        padding-right: var(--sp2);
-  }
-
-      html[dir="ltr"]:not(.js) body.is-always-mobile-nav .header-nav {
-        padding-right: var(--sp2);
-  }
-
-      html[dir="rtl"]:not(.js) body.is-always-mobile-nav .header-nav {
-        padding-left: var(--sp2);
-  }
-
       html:not(.js) body.is-always-mobile-nav .header-nav {
         border: solid 1px var(--color--gray-95) !important;
       }
@@ -182,21 +116,19 @@
         flex-basis: 100%;
         width: 100%;
         max-width: none;
-        margin-top: var(--sp2);
-        margin-bottom: 0;
-        padding-top: var(--sp2);
-        padding-bottom: 0;
+        margin-block: var(--sp2) 0;
+        margin-inline-start: var(--sp2);
+        margin-inline-end: var(--sp2);
+        padding-block: var(--sp2) 0;
+        padding-inline-start: var(--sp2);
+        padding-inline-end: var(--sp2);
         transform: none;
         box-shadow: 0 0 36px var(--color--gray-90);
       }
 
-      html[dir="ltr"]:not(.js) body.is-always-mobile-nav .primary-nav__menu--level-2 {
-        border-left: 0;
-  }
-
-      html[dir="rtl"]:not(.js) body.is-always-mobile-nav .primary-nav__menu--level-2 {
-        border-right: 0;
-  }
+      html:not(.js) body.is-always-mobile-nav .primary-nav__menu--level-2 {
+        border-inline-start: 0;
+      }
 
       html:not(.js) body.is-always-mobile-nav .primary-nav__button-toggle {
         display: none;
diff --git a/core/themes/olivero/css/components/navigation/nav-primary-wide.css b/core/themes/olivero/css/components/navigation/nav-primary-wide.css
index 11bc11bbf26..e9ecca5ef0a 100644
--- a/core/themes/olivero/css/components/navigation/nav-primary-wide.css
+++ b/core/themes/olivero/css/components/navigation/nav-primary-wide.css
@@ -59,14 +59,9 @@
           border: solid 2px var(--color--primary-50);
           border-radius: 0.25rem;
         }
-      [dir="ltr"] body:not(.is-always-mobile-nav) .primary-nav__menu-link--button.primary-nav__menu-link--has-children {
-        padding-right: 0.5625rem;
-    }
-      [dir="rtl"] body:not(.is-always-mobile-nav) .primary-nav__menu-link--button.primary-nav__menu-link--has-children {
-        padding-left: 0.5625rem;
-    }
       body:not(.is-always-mobile-nav) .primary-nav__menu-link--button.primary-nav__menu-link--has-children {
         overflow: visible; /* Necessary to view icon in IE11 */
+        padding-inline-end: 0.5625rem;
       }
 
         body:not(.is-always-mobile-nav) .primary-nav__menu-link--button.primary-nav__menu-link--has-children:focus:before {
@@ -79,18 +74,13 @@
         }
 
         /* Chevron icon for desktop navigation. */
-        [dir="ltr"] body:not(.is-always-mobile-nav) .primary-nav__menu-link--button.primary-nav__menu-link--has-children:after {
-          left: calc(100% - 0.1875rem);
-    }
-        [dir="rtl"] body:not(.is-always-mobile-nav) .primary-nav__menu-link--button.primary-nav__menu-link--has-children:after {
-          right: calc(100% - 0.1875rem);
-    }
         body:not(.is-always-mobile-nav) .primary-nav__menu-link--button.primary-nav__menu-link--has-children:after {
           position: absolute;
-          top: 50%;
+          inset-block-start: 50%;
+          inset-inline-start: calc(100% - 0.1875rem);
           width: 0.5rem;
           height: 0.5rem;
-          margin-top: -2px;
+          margin-block-start: -2px;
           transform: translateY(-50%) rotate(45deg);
           /* Intentionally not using CSS logical properties. */
           border-top: 0;
@@ -102,25 +92,10 @@
           opacity: 1;
         }
 
-    [dir="ltr"] body:not(.is-always-mobile-nav) .primary-nav__menu-link-inner {
-      padding-left: 0;
-    }
-
-    [dir="rtl"] body:not(.is-always-mobile-nav) .primary-nav__menu-link-inner {
-      padding-right: 0;
-    }
-
-    [dir="ltr"] body:not(.is-always-mobile-nav) .primary-nav__menu-link-inner {
-      padding-right: 0;
-    }
-
-    [dir="rtl"] body:not(.is-always-mobile-nav) .primary-nav__menu-link-inner {
-      padding-left: 0;
-    }
-
     body:not(.is-always-mobile-nav) .primary-nav__menu-link-inner {
-      padding-top: var(--sp2);
-      padding-bottom: var(--sp2);
+      padding-block: var(--sp2);
+      padding-inline-start: 0;
+      padding-inline-end: 0;
     }
 
       body:not(.is-always-mobile-nav) .primary-nav__menu-link-inner:after {
@@ -128,33 +103,10 @@
         border-top-width: var(--sp0-5);
       }
 
-    [dir="ltr"] body:not(.is-always-mobile-nav) .primary-nav__menu--level-1 {
-      margin-right: var(--sp);
-    }
-
-    [dir="rtl"] body:not(.is-always-mobile-nav) .primary-nav__menu--level-1 {
-      margin-left: var(--sp);
-    }
-
     body:not(.is-always-mobile-nav) .primary-nav__menu--level-1 {
       display: flex;
       align-items: stretch;
-    }
-
-    [dir="ltr"] body:not(.is-always-mobile-nav) .primary-nav__menu-item--level-1 {
-      margin-left: 0;
-    }
-
-    [dir="rtl"] body:not(.is-always-mobile-nav) .primary-nav__menu-item--level-1 {
-      margin-right: 0;
-    }
-
-    [dir="ltr"] body:not(.is-always-mobile-nav) .primary-nav__menu-item--level-1 {
-      margin-right: 0;
-    }
-
-    [dir="rtl"] body:not(.is-always-mobile-nav) .primary-nav__menu-item--level-1 {
-      margin-left: 0;
+      margin-inline-end: var(--sp);
     }
 
     body:not(.is-always-mobile-nav) .primary-nav__menu-item--level-1 {
@@ -163,41 +115,14 @@
       align-items: center;
       width: max-content;
       max-width: 12.5rem;
-      margin-top: 0;
-      margin-bottom: 0;
+      margin-block: 0;
+      margin-inline-start: 0;
+      margin-inline-end: 0;
     }
 
-      [dir="ltr"] body:not(.is-always-mobile-nav) .primary-nav__menu-item--level-1:not(:last-child) {
-        margin-right: var(--sp2);
-    }
-
-      [dir="rtl"] body:not(.is-always-mobile-nav) .primary-nav__menu-item--level-1:not(:last-child) {
-        margin-left: var(--sp2);
-    }
-
-    [dir="ltr"] body:not(.is-always-mobile-nav) .primary-nav__menu--level-2 {
-      margin-left: 0;
-    }
-
-    [dir="rtl"] body:not(.is-always-mobile-nav) .primary-nav__menu--level-2 {
-      margin-right: 0;
-    }
-
-    [dir="ltr"] body:not(.is-always-mobile-nav) .primary-nav__menu--level-2 {
-      padding-left: var(--sp2);
-    }
-
-    [dir="rtl"] body:not(.is-always-mobile-nav) .primary-nav__menu--level-2 {
-      padding-right: var(--sp2);
-    }
-
-    [dir="ltr"] body:not(.is-always-mobile-nav) .primary-nav__menu--level-2 {
-      padding-right: var(--sp2);
-    }
-
-    [dir="rtl"] body:not(.is-always-mobile-nav) .primary-nav__menu--level-2 {
-      padding-left: var(--sp2);
-    }
+      body:not(.is-always-mobile-nav) .primary-nav__menu-item--level-1:not(:last-child) {
+        margin-inline-end: var(--sp2);
+      }
 
     body:not(.is-always-mobile-nav) .primary-nav__menu--level-2 {
       position: absolute;
@@ -210,9 +135,11 @@
       /* Ensure that long level-2 menus will never overflow viewport (focused
        * elements should always be in viewport per accessibility guidelines). */
       max-height: calc(100vh - var(--site-header-height-wide) - var(--drupal-displace-offset-top, 0px) - var(--drupal-displace-offset-bottom, 0px) - var(--sp));
-      margin-top: 0;
-      padding-top: calc(3 * var(--sp));
-      padding-bottom: calc(3 * var(--sp));
+      margin-block-start: 0;
+      margin-inline-start: 0;
+      padding-block: calc(3 * var(--sp));
+      padding-inline-start: var(--sp2);
+      padding-inline-end: var(--sp2);
       transition: none;
       transform: translate(-50%, -1.25rem);
       opacity: 0;
@@ -228,7 +155,7 @@
 
       body:not(.is-always-mobile-nav) .primary-nav__menu--level-2.is-active-menu-parent {
         visibility: visible;
-        margin-top: 0;
+        margin-block-start: 0;
         transform: translate(-50%, 0);
         opacity: 1;
       }
@@ -244,25 +171,10 @@
         transform: none;
       }
 
-      [dir="ltr"] body:not(.is-always-mobile-nav) .primary-nav__menu-link--level-2 .primary-nav__menu-link-inner {
-        padding-left: 0;
-    }
-
-      [dir="rtl"] body:not(.is-always-mobile-nav) .primary-nav__menu-link--level-2 .primary-nav__menu-link-inner {
-        padding-right: 0;
-    }
-
-      [dir="ltr"] body:not(.is-always-mobile-nav) .primary-nav__menu-link--level-2 .primary-nav__menu-link-inner {
-        padding-right: 0;
-    }
-
-      [dir="rtl"] body:not(.is-always-mobile-nav) .primary-nav__menu-link--level-2 .primary-nav__menu-link-inner {
-        padding-left: 0;
-    }
-
       body:not(.is-always-mobile-nav) .primary-nav__menu-link--level-2 .primary-nav__menu-link-inner {
-        padding-top: var(--sp0-5);
-        padding-bottom: var(--sp0-5);
+        padding-block: var(--sp0-5);
+        padding-inline-start: 0;
+        padding-inline-end: 0;
       }
 
         body:not(.is-always-mobile-nav) .primary-nav__menu-link--level-2 .primary-nav__menu-link-inner:after {
diff --git a/core/themes/olivero/css/components/navigation/nav-primary.css b/core/themes/olivero/css/components/navigation/nav-primary.css
index 1b5b88b2dfc..9dbaf9f4f1b 100644
--- a/core/themes/olivero/css/components/navigation/nav-primary.css
+++ b/core/themes/olivero/css/components/navigation/nav-primary.css
@@ -29,11 +29,11 @@
 }
 
 .primary-nav__menu-item {
-  margin-bottom: var(--sp0-5);
+  margin-block-end: var(--sp0-5);
 }
 
 .primary-nav__menu-item:last-child {
-    margin-bottom: 0;
+    margin-block-end: 0;
   }
 
 .primary-nav__menu-item.primary-nav__menu-item--has-children {
@@ -66,89 +66,36 @@
     outline-offset: 2px;
   }
 
-[dir="ltr"] .primary-nav__menu-link--nolink {
-  padding-left: 0;
-}
-
-[dir="rtl"] .primary-nav__menu-link--nolink {
-  padding-right: 0;
-}
-
-[dir="ltr"] .primary-nav__menu-link--nolink {
-  padding-right: 0;
-}
-
-[dir="rtl"] .primary-nav__menu-link--nolink {
-  padding-left: 0;
-}
-
 .primary-nav__menu-link--nolink {
-  padding-top: var(--sp0-5);
-  padding-bottom: var(--sp0-5);
+  padding-block: var(--sp0-5);
+  padding-inline-start: 0;
+  padding-inline-end: 0;
   color: var(--color-text-neutral-soft);
   font-weight: normal;
 }
 
-[dir="ltr"] .primary-nav__menu-link--button {
-  padding-left: 0;
-}
-
-[dir="rtl"] .primary-nav__menu-link--button {
-  padding-right: 0;
-}
-
-[dir="ltr"] .primary-nav__menu-link--button {
-  padding-right: 0;
-}
-
-[dir="rtl"] .primary-nav__menu-link--button {
-  padding-left: 0;
-}
-
-[dir="ltr"] .primary-nav__menu-link--button {
-  text-align: left;
-}
-
-[dir="rtl"] .primary-nav__menu-link--button {
-  text-align: right;
-}
-
 .primary-nav__menu-link--button {
   position: relative;
-  padding-top: 0;
-  padding-bottom: 0;
+  padding-block: 0;
+  padding-inline-start: 0;
+  padding-inline-end: 0;
   cursor: pointer;
+  text-align: start;
   border: 0;
   background: transparent;
 
   /* Plus icon for mobile navigation. */
 }
 
-[dir="ltr"] .primary-nav__menu-link--button.primary-nav__menu-link--has-children {
-    padding-right: var(--sp3);
-}
-
-[dir="rtl"] .primary-nav__menu-link--button.primary-nav__menu-link--has-children {
-    padding-left: var(--sp3);
-}
-
-.primary-nav__menu-link--button.primary-nav__menu-link--has-children { /* Ensure text does not overlap icon. */
+.primary-nav__menu-link--button.primary-nav__menu-link--has-children {
+    padding-inline-end: var(--sp3); /* Ensure text does not overlap icon. */
   }
 
-[dir="ltr"] .primary-nav__menu-link--button.primary-nav__menu-link--has-children:before,[dir="ltr"] 
-    .primary-nav__menu-link--button.primary-nav__menu-link--has-children:after {
-      right: 0.5625rem;
-}
-
-[dir="rtl"] .primary-nav__menu-link--button.primary-nav__menu-link--has-children:before,[dir="rtl"] 
-    .primary-nav__menu-link--button.primary-nav__menu-link--has-children:after {
-      left: 0.5625rem;
-}
-
 .primary-nav__menu-link--button.primary-nav__menu-link--has-children:before,
     .primary-nav__menu-link--button.primary-nav__menu-link--has-children:after {
       position: absolute;
-      top: calc(var(--sp0-5) + 1.0625rem); /* Visually align button with menu link text. */
+      inset-inline-end: 0.5625rem;
+      inset-block-start: calc(var(--sp0-5) + 1.0625rem); /* Visually align button with menu link text. */
       width: 1.125rem;
       height: 0;
       content: "";
@@ -165,41 +112,19 @@
       opacity: 0;
     }
 
-[dir="ltr"] .primary-nav__menu-link-inner {
-  padding-left: 0;
-}
-
-[dir="rtl"] .primary-nav__menu-link-inner {
-  padding-right: 0;
-}
-
-[dir="ltr"] .primary-nav__menu-link-inner {
-  padding-right: 0;
-}
-
-[dir="rtl"] .primary-nav__menu-link-inner {
-  padding-left: 0;
-}
-
 .primary-nav__menu-link-inner {
   position: relative;
   display: inline-flex;
   align-items: center;
-  padding-top: var(--sp0-5);
-  padding-bottom: var(--sp0-5);
-}
-
-[dir="ltr"] .primary-nav__menu-link-inner:after {
-    left: 0;
-}
-
-[dir="rtl"] .primary-nav__menu-link-inner:after {
-    right: 0;
+  padding-block: var(--sp0-5);
+  padding-inline-start: 0;
+  padding-inline-end: 0;
 }
 
 .primary-nav__menu-link-inner:after {
     position: absolute;
-    bottom: 0;
+    inset-block-end: 0;
+    inset-inline-start: 0;
     width: 100%;
     height: 0;
     content: "";
@@ -218,43 +143,13 @@
   Top level specific styles.
 */
 
-[dir="ltr"] .primary-nav__menu--level-1 {
-  margin-left: 0;
-}
-
-[dir="rtl"] .primary-nav__menu--level-1 {
-  margin-right: 0;
-}
-
-[dir="ltr"] .primary-nav__menu--level-1 {
-  margin-right: 0;
-}
-
-[dir="rtl"] .primary-nav__menu--level-1 {
-  margin-left: 0;
-}
-
-[dir="ltr"] .primary-nav__menu--level-1 {
-  padding-left: 0;
-}
-
-[dir="rtl"] .primary-nav__menu--level-1 {
-  padding-right: 0;
-}
-
-[dir="ltr"] .primary-nav__menu--level-1 {
-  padding-right: 0;
-}
-
-[dir="rtl"] .primary-nav__menu--level-1 {
-  padding-left: 0;
-}
-
 .primary-nav__menu--level-1 {
-  margin-top: 0;
-  margin-bottom: 0;
-  padding-top: 0;
-  padding-bottom: 0;
+  margin-block: 0;
+  margin-inline-start: 0;
+  margin-inline-end: 0;
+  padding-block: 0;
+  padding-inline-start: 0;
+  padding-inline-end: 0;
 }
 
 .primary-nav__menu-link--level-1 {
@@ -267,65 +162,32 @@
   Secondary menu specific styles.
 */
 
-[dir="ltr"] .primary-nav__menu--level-2 {
-  margin-left: calc(-1 * var(--sp));
-}
-
-[dir="rtl"] .primary-nav__menu--level-2 {
-  margin-right: calc(-1 * var(--sp));
-}
-
-[dir="ltr"] .primary-nav__menu--level-2 {
-  padding-left: var(--sp2-5);
-}
-
-[dir="rtl"] .primary-nav__menu--level-2 {
-  padding-right: var(--sp2-5);
-}
-
-[dir="ltr"] .primary-nav__menu--level-2 {
-  border-left: solid var(--sp) var(--color--primary-50);
-}
-
-[dir="rtl"] .primary-nav__menu--level-2 {
-  border-right: solid var(--sp) var(--color--primary-50);
-}
-
 .primary-nav__menu--level-2 {
   visibility: hidden;
   overflow: hidden;
   flex-basis: 100%;
   max-height: 0;
-  margin-top: 0;
-  margin-bottom: 0;
+  margin-block: 0;
+  margin-inline-start: calc(-1 * var(--sp));
+  padding-inline-start: var(--sp2-5);
   transition: opacity 0.2s, visibility 0.2s, max-height 0.2s;
   opacity: 0;
+  border-inline-start: solid var(--sp) var(--color--primary-50);
 }
 
 .primary-nav__menu--level-2.is-active-menu-parent {
     visibility: visible;
     max-height: none;
-    margin-top: var(--sp1-5);
+    margin-block-start: var(--sp1-5);
     opacity: 1;
   }
 
 @media (min-width: 43.75rem) {
 
-[dir="ltr"] .primary-nav__menu--level-2 {
-    margin-left: calc(-1 * var(--sp3));
-  }
-
-[dir="rtl"] .primary-nav__menu--level-2 {
-    margin-right: calc(-1 * var(--sp3));
-  }
-
-[dir="ltr"] .primary-nav__menu--level-2 {
-    padding-left: var(--sp3);
-  }
-
-[dir="rtl"] .primary-nav__menu--level-2 {
-    padding-right: var(--sp3);
-  }
+.primary-nav__menu--level-2 {
+    margin-inline-start: calc(-1 * var(--sp3));
+    padding-inline-start: var(--sp3);
+}
   }
 
 /*
diff --git a/core/themes/olivero/css/components/navigation/nav-secondary.css b/core/themes/olivero/css/components/navigation/nav-secondary.css
index 89f88a19241..6d8da2f31d6 100644
--- a/core/themes/olivero/css/components/navigation/nav-secondary.css
+++ b/core/themes/olivero/css/components/navigation/nav-secondary.css
@@ -29,45 +29,15 @@
   font-weight: 600;
 }
 
-[dir="ltr"] .secondary-nav__menu {
-  margin-left: 0;
-}
-
-[dir="rtl"] .secondary-nav__menu {
-  margin-right: 0;
-}
-
-[dir="ltr"] .secondary-nav__menu {
-  margin-right: 0;
-}
-
-[dir="rtl"] .secondary-nav__menu {
-  margin-left: 0;
-}
-
-[dir="ltr"] .secondary-nav__menu {
-  padding-left: 0;
-}
-
-[dir="rtl"] .secondary-nav__menu {
-  padding-right: 0;
-}
-
-[dir="ltr"] .secondary-nav__menu {
-  padding-right: 0;
-}
-
-[dir="rtl"] .secondary-nav__menu {
-  padding-left: 0;
-}
-
 .secondary-nav__menu {
   display: flex;
   align-items: center;
-  margin-top: 0;
-  margin-bottom: 0;
-  padding-top: 0;
-  padding-bottom: 0;
+  margin-block: 0;
+  margin-inline-start: 0;
+  margin-inline-end: 0;
+  padding-block: 0;
+  padding-inline-start: 0;
+  padding-inline-end: 0;
   list-style: none;
 }
 
@@ -82,13 +52,9 @@
   max-width: 12.5rem;
 }
 
-[dir="ltr"] .secondary-nav__menu-item:not(:last-child) {
-    margin-right: var(--sp1-5);
-}
-
-[dir="rtl"] .secondary-nav__menu-item:not(:last-child) {
-    margin-left: var(--sp1-5);
-}
+.secondary-nav__menu-item:not(:last-child) {
+    margin-inline-end: var(--sp1-5);
+  }
 
 .secondary-nav__menu-link {
   position: relative;
@@ -119,34 +85,17 @@
     }
 
 @media (min-width: 75rem) {
-    [dir="ltr"] body:not(.is-always-mobile-nav) .secondary-nav {
-      margin-left: var(--sp);
-  }
-    [dir="rtl"] body:not(.is-always-mobile-nav) .secondary-nav {
-      margin-right: var(--sp);
-  }
-    [dir="ltr"] body:not(.is-always-mobile-nav) .secondary-nav {
-      padding-left: var(--sp2);
-  }
-    [dir="rtl"] body:not(.is-always-mobile-nav) .secondary-nav {
-      padding-right: var(--sp2);
-  }
     body:not(.is-always-mobile-nav) .secondary-nav {
       position: relative;
       display: flex;
+      margin-inline-start: var(--sp);
+      padding-inline-start: var(--sp2);
     }
 
-      [dir="ltr"] body:not(.is-always-mobile-nav) .secondary-nav:before {
-        left: 0;
-  }
-
-      [dir="rtl"] body:not(.is-always-mobile-nav) .secondary-nav:before {
-        right: 0;
-  }
-
       body:not(.is-always-mobile-nav) .secondary-nav:before {
         position: absolute;
-        top: 50%;
+        inset-block-start: 50%;
+        inset-inline-start: 0;
         width: 2px;
         height: var(--sp2);
         content: "";
@@ -154,13 +103,9 @@
         background-color: var(--color--gray-90);
       }
 
-    [dir="ltr"] body:not(.is-always-mobile-nav) .secondary-nav__menu-item:not(:last-child) {
-      margin-right: var(--sp2);
-  }
-
-    [dir="rtl"] body:not(.is-always-mobile-nav) .secondary-nav__menu-item:not(:last-child) {
-      margin-left: var(--sp2);
-  }
+    body:not(.is-always-mobile-nav) .secondary-nav__menu-item:not(:last-child) {
+      margin-inline-end: var(--sp2);
+    }
       body:not(.is-always-mobile-nav) .secondary-nav__menu-link:focus {
         position: relative;
         outline: 0;
diff --git a/core/themes/olivero/css/components/navigation/wide-nav-expand.css b/core/themes/olivero/css/components/navigation/wide-nav-expand.css
index 00003e20bfb..1aa3fbda04d 100644
--- a/core/themes/olivero/css/components/navigation/wide-nav-expand.css
+++ b/core/themes/olivero/css/components/navigation/wide-nav-expand.css
@@ -81,52 +81,30 @@ body.is-always-mobile-nav .wide-nav-expand {
     border-top: solid 3px currentColor;
   }
 
-[dir="ltr"] .wide-nav-expand__icon > span:nth-child(1) {
-      left: 0;
-}
-
-[dir="rtl"] .wide-nav-expand__icon > span:nth-child(1) {
-      right: 0;
-}
-
 .wide-nav-expand__icon > span:nth-child(1) {
       position: absolute;
-      top: 0;
+      inset-block-start: 0;
+      inset-inline-start: 0;
       width: 100%;
       height: 0;
       transition: transform 0.2s;
       background-color: currentColor;
     }
 
-[dir="ltr"] .wide-nav-expand__icon > span:nth-child(2) {
-      left: 0;
-}
-
-[dir="rtl"] .wide-nav-expand__icon > span:nth-child(2) {
-      right: 0;
-}
-
 .wide-nav-expand__icon > span:nth-child(2) {
       position: absolute;
-      top: 0.5625rem;
+      inset-block-start: 0.5625rem;
+      inset-inline-start: 0;
       width: 100%;
       height: 0;
       transition: opacity 0.2s;
       background-color: currentColor;
     }
 
-[dir="ltr"] .wide-nav-expand__icon > span:nth-child(3) {
-      left: 0;
-}
-
-[dir="rtl"] .wide-nav-expand__icon > span:nth-child(3) {
-      right: 0;
-}
-
 .wide-nav-expand__icon > span:nth-child(3) {
       position: absolute;
-      top: auto;
-      bottom: 0;
+      inset-block: auto 0;
+      inset-inline-start: 0;
       width: 100%;
       height: 0;
       transition: transform 0.2s;
@@ -138,7 +116,7 @@ body.is-always-mobile-nav .wide-nav-expand {
 }
 
 [aria-expanded="true"] .wide-nav-expand__icon > span:nth-child(1) {
-    top: 0.5625rem;
+    inset-block-start: 0.5625rem;
     transform: rotate(-45deg);
   }
 
@@ -147,6 +125,6 @@ body.is-always-mobile-nav .wide-nav-expand {
   }
 
 [aria-expanded="true"] .wide-nav-expand__icon > span:nth-child(3) {
-    top: 0.5625rem;
+    inset-block-start: 0.5625rem;
     transform: rotate(45deg);
   }
diff --git a/core/themes/olivero/css/components/node-preview-container.css b/core/themes/olivero/css/components/node-preview-container.css
index ccc947bc036..38961fef704 100644
--- a/core/themes/olivero/css/components/node-preview-container.css
+++ b/core/themes/olivero/css/components/node-preview-container.css
@@ -23,25 +23,10 @@
 
 /* Width of the entire grid maxes out. */
 
-[dir="ltr"] .node-preview-container {
-  padding-left: var(--sp0-5);
-}
-
-[dir="rtl"] .node-preview-container {
-  padding-right: var(--sp0-5);
-}
-
-[dir="ltr"] .node-preview-container {
-  padding-right: var(--sp0-5);
-}
-
-[dir="rtl"] .node-preview-container {
-  padding-left: var(--sp0-5);
-}
-
 .node-preview-container {
-  padding-top: 0;
-  padding-bottom: 0;
+  padding-block: 0;
+  padding-inline-start: var(--sp0-5);
+  padding-inline-end: var(--sp0-5);
   background: var(--color--white);
   box-shadow: -36px 1px 36px rgba(0, 0, 0, 0.08); /* LTR */
 }
@@ -60,23 +45,8 @@ body.toolbar-vertical.toolbar-tray-open .node-preview-container {
   align-items: center;
 }
 
-[dir="ltr"] .node-preview-backlink {
-  margin-left: 0;
-}
-
-[dir="rtl"] .node-preview-backlink {
-  margin-right: 0;
-}
-
-[dir="ltr"] .node-preview-backlink {
-  margin-right: auto;
-}
-
-[dir="rtl"] .node-preview-backlink {
-  margin-left: auto;
-}
-
 .node-preview-backlink {
-  margin-top: var(--sp0-5);
-  margin-bottom: var(--sp0-5);
+  margin-block: var(--sp0-5);
+  margin-inline-start: 0;
+  margin-inline-end: auto;
 }
diff --git a/core/themes/olivero/css/components/node-teaser.css b/core/themes/olivero/css/components/node-teaser.css
index 52b69e3e3a3..e2bd5e64ed6 100644
--- a/core/themes/olivero/css/components/node-teaser.css
+++ b/core/themes/olivero/css/components/node-teaser.css
@@ -25,12 +25,12 @@
 
 .node--view-mode-teaser {
   position: relative; /* Anchor after pseudo-element. */
-  margin-bottom: var(--sp1-5);
+  margin-block-end: var(--sp1-5);
 }
 
 .node--view-mode-teaser:after {
     position: absolute;
-    bottom: 0;
+    inset-block-end: 0;
     width: var(--sp3);
     height: 0;
     content: "";
@@ -39,7 +39,7 @@
   }
 
 .node--view-mode-teaser .node__meta {
-    margin-bottom: var(--sp);
+    margin-block-end: var(--sp);
   }
 
 .node--view-mode-teaser .node__meta a {
@@ -61,18 +61,11 @@
   }
     }
 
-[dir="ltr"] .node--view-mode-teaser .primary-image {
-    margin-right: var(--sp1);
-}
-
-[dir="rtl"] .node--view-mode-teaser .primary-image {
-    margin-left: var(--sp1);
-}
-
 .node--view-mode-teaser .primary-image {
     flex-shrink: 0;
     margin: 0;
-    margin-bottom: var(--sp1);
+    margin-block-end: var(--sp1);
+    margin-inline-end: var(--sp1);
 
     /* Ensure title does not wrap under image until necessary. */
   }
@@ -109,24 +102,17 @@
 
 @media (min-width: 62.5rem) {
 
-[dir="ltr"] .node--view-mode-teaser .primary-image {
-      left: calc(-1 * ((var(--grid-col-width) + var(--grid-gap))));
-  }
-
-[dir="rtl"] .node--view-mode-teaser .primary-image {
-      right: calc(-1 * ((var(--grid-col-width) + var(--grid-gap))));
-  }
-
 .node--view-mode-teaser .primary-image {
       position: absolute;
-      top: 0;
+      inset-block-start: 0;
+      inset-inline-start: calc(-1 * ((var(--grid-col-width) + var(--grid-gap))));
       margin: 0;
   }
     }
 
 .node--view-mode-teaser .node__title {
     margin: 0;
-    margin-bottom: var(--sp1);
+    margin-block-end: var(--sp1);
     color: var(--color-text-neutral-loud);
     font-size: 1.5rem;
     line-height: var(--line-height-base);
@@ -140,60 +126,31 @@
   }
     }
 
-[dir="ltr"] .node--view-mode-teaser .field--tag-ref {
-    margin-left: 0;
-}
-
-[dir="rtl"] .node--view-mode-teaser .field--tag-ref {
-    margin-right: 0;
-}
-
-[dir="ltr"] .node--view-mode-teaser .field--tag-ref {
-    margin-right: 0;
-}
-
-[dir="rtl"] .node--view-mode-teaser .field--tag-ref {
-    margin-left: 0;
-}
-
-[dir="ltr"] .node--view-mode-teaser .field--tag-ref {
-    padding-left: 0;
-}
-
-[dir="rtl"] .node--view-mode-teaser .field--tag-ref {
-    padding-right: 0;
-}
-
-[dir="ltr"] .node--view-mode-teaser .field--tag-ref {
-    padding-right: 0;
-}
-
-[dir="rtl"] .node--view-mode-teaser .field--tag-ref {
-    padding-left: 0;
-}
-
 .node--view-mode-teaser .field--tag-ref {
-    margin-top: var(--sp1);
-    margin-bottom: 0;
-    padding-top: 0;
-    padding-bottom: 0;
+    margin-block-start: var(--sp1);
+    margin-block-end: 0;
+    margin-inline-start: 0;
+    margin-inline-end: 0;
+    padding-block: 0;
+    padding-inline-start: 0;
+    padding-inline-end: 0;
     background-color: transparent;
   }
 
 @media (min-width: 62.5rem) {
 
 .node--view-mode-teaser .field--tag-ref {
-      margin-top: var(--sp2);
+      margin-block-start: var(--sp2);
   }
     }
 
 @media (min-width: 62.5rem) {
 
 .node--view-mode-teaser {
-    margin-bottom: var(--sp3);
+    margin-block-end: var(--sp3);
 }
   }
 
 .views-row:last-child .node--view-mode-teaser {
-  margin-bottom: 0;
+  margin-block-end: 0;
 }
diff --git a/core/themes/olivero/css/components/node.css b/core/themes/olivero/css/components/node.css
index 93acf6b3937..ce6a64e2184 100644
--- a/core/themes/olivero/css/components/node.css
+++ b/core/themes/olivero/css/components/node.css
@@ -26,7 +26,7 @@
 .node__meta {
   display: flex;
   align-items: center;
-  margin-bottom: var(--sp1);
+  margin-block-end: var(--sp1);
   color: var(--color-text-neutral-soft);
   font-size: 0.875rem;
   line-height: var(--sp);
@@ -39,27 +39,20 @@
 @media (min-width: 31.25rem) {
 
 .node__meta {
-    margin-bottom: var(--sp2);
+    margin-block-end: var(--sp2);
 }
   }
 
-[dir="ltr"] .node__author-image img {
-  margin-right: var(--sp0-5);
-}
-
-[dir="rtl"] .node__author-image img {
-  margin-left: var(--sp0-5);
-}
-
 .node__author-image img {
   width: var(--sp2-5);
   height: var(--sp2-5);
+  margin-inline-end: var(--sp0-5);
   object-fit: cover;
   border-radius: 50%;
 }
 
 .node__title a {
-    padding-bottom: 0.1875rem;
+    padding-block-end: 0.1875rem;
     transition: background-size 0.2s, color 0.2s;
     text-decoration: none;
     color: var(--color-text-neutral-loud);
@@ -80,13 +73,13 @@
 }
 
 .node__content {
-  padding-bottom: var(--sp1-5);
+  padding-block-end: var(--sp1-5);
 }
 
 @media (min-width: 62.5rem) {
 
 .node__content {
-    padding-bottom: var(--sp3);
+    padding-block-end: var(--sp3);
 }
   }
 
diff --git a/core/themes/olivero/css/components/pager.css b/core/themes/olivero/css/components/pager.css
index ba92996478f..b0d26ab46c2 100644
--- a/core/themes/olivero/css/components/pager.css
+++ b/core/themes/olivero/css/components/pager.css
@@ -23,38 +23,15 @@
 
 /* Width of the entire grid maxes out. */
 
-[dir="ltr"] .pager__items {
-  margin-left: 0;
-}
-
-[dir="rtl"] .pager__items {
-  margin-right: 0;
-}
-
-[dir="ltr"] .pager__items {
-  padding-left: 0;
-}
-
-[dir="rtl"] .pager__items {
-  padding-right: 0;
-}
-
-[dir="ltr"] .pager__items {
-  padding-right: 0;
-}
-
-[dir="rtl"] .pager__items {
-  padding-left: 0;
-}
-
 .pager__items {
   display: flex;
   flex-wrap: wrap;
   align-items: flex-end;
-  margin-top: 0;
-  margin-bottom: 0;
-  padding-top: 0;
-  padding-bottom: 0;
+  margin-block: 0;
+  margin-inline-start: 0;
+  padding-block: 0;
+  padding-inline-start: 0;
+  padding-inline-end: 0;
   list-style: none;
   font-weight: bold;
 }
diff --git a/core/themes/olivero/css/components/powered-by-block.css b/core/themes/olivero/css/components/powered-by-block.css
index d480cc3cba0..90e3c450418 100644
--- a/core/themes/olivero/css/components/powered-by-block.css
+++ b/core/themes/olivero/css/components/powered-by-block.css
@@ -38,17 +38,10 @@
       text-decoration: none;
     }
 
-[dir="ltr"] .block-system-powered-by-block .drupal-logo {
-    margin-left: calc(var(--sp) / 4);
-}
-
-[dir="rtl"] .block-system-powered-by-block .drupal-logo {
-    margin-right: calc(var(--sp) / 4);
-}
-
 .block-system-powered-by-block .drupal-logo {
     display: inline-block;
-    margin-top: calc(-1 * var(--sp) / 4);
+    margin-block-start: calc(-1 * var(--sp) / 4);
+    margin-inline-start: calc(var(--sp) / 4);
   }
 
 .block-system-powered-by-block svg {
diff --git a/core/themes/olivero/css/components/progress.css b/core/themes/olivero/css/components/progress.css
index 3719bf22ba2..3c1b43f5234 100644
--- a/core/themes/olivero/css/components/progress.css
+++ b/core/themes/olivero/css/components/progress.css
@@ -35,10 +35,6 @@
   background-color: var(--color--primary-40);
 }
 
-[dir="ltr"] .progress__percentage {
-  margin-left: 1rem;
-}
-
-[dir="rtl"] .progress__percentage {
-  margin-right: 1rem;
+.progress__percentage {
+  margin-inline-start: 1rem;
 }
diff --git a/core/themes/olivero/css/components/search-results.css b/core/themes/olivero/css/components/search-results.css
index 553922c9cd9..6927cf61cd1 100644
--- a/core/themes/olivero/css/components/search-results.css
+++ b/core/themes/olivero/css/components/search-results.css
@@ -23,62 +23,32 @@
 
 /* Width of the entire grid maxes out. */
 
-[dir="ltr"] .search-results {
-  padding-left: 0;
-}
-
-[dir="rtl"] .search-results {
-  padding-right: 0;
-}
-
-[dir="ltr"] .search-results {
-  padding-right: 0;
-}
-
-[dir="rtl"] .search-results {
-  padding-left: 0;
-}
-
 .search-results {
-  margin-bottom: var(--sp2);
-  padding-top: 0;
-  padding-bottom: 0;
+  margin-block-end: var(--sp2);
+  padding-block: 0;
+  padding-inline-start: 0;
+  padding-inline-end: 0;
   list-style: none;
 }
 
 @media (min-width: 43.75rem) {
 
 .search-results {
-    margin-bottom: var(--sp3);
+    margin-block-end: var(--sp3);
 }
   }
 
-[dir="ltr"] .search-result__title {
-  margin-left: 0;
-}
-
-[dir="rtl"] .search-result__title {
-  margin-right: 0;
-}
-
-[dir="ltr"] .search-result__title {
-  margin-right: 0;
-}
-
-[dir="rtl"] .search-result__title {
-  margin-left: 0;
-}
-
 .search-result__title {
-  margin-top: 0;
-  margin-bottom: 0;
+  margin-block: 0;
+  margin-inline-start: 0;
+  margin-inline-end: 0;
   color: var(--color-text-neutral-loud);
   font-size: 1.25rem;
   line-height: var(--line-height-base);
 }
 
 .search-result__title a {
-    padding-bottom: 0.1875rem;
+    padding-block-end: 0.1875rem;
     transition: background-size 0.2s, color 0.2s;
     text-decoration: none;
     background-color: transparent;
@@ -95,7 +65,7 @@
 @media (min-width: 62.5rem) {
 
 .search-result__title {
-    margin-bottom: var(--sp1);
+    margin-block-end: var(--sp1);
     font-size: 1.875rem;
     line-height: var(--sp3);
 }
@@ -106,20 +76,20 @@
 }
 
 .search-result__snippet {
-  padding-bottom: calc(var(--sp1-5) - 2px);
+  padding-block-end: calc(var(--sp1-5) - 2px);
 }
 
 @media (min-width: 62.5rem) {
 
 .search-result__snippet {
-    padding-bottom: var(--sp3);
+    padding-block-end: var(--sp3);
 }
   }
 
 .search-result__meta {
   display: flex;
   align-items: center;
-  margin-bottom: var(--sp1);
+  margin-block-end: var(--sp1);
   color: var(--color-text-neutral-soft);
   font-size: 0.875rem;
   line-height: var(--sp);
@@ -132,12 +102,12 @@
 
 .search-results__item {
   position: relative; /* Anchor after pseudo-element. */
-  margin-bottom: var(--sp1-5);
+  margin-block-end: var(--sp1-5);
 }
 
 .search-results__item:after {
     position: absolute;
-    bottom: 0;
+    inset-block-end: 0;
     width: var(--sp3);
     height: 0;
     content: "";
@@ -146,12 +116,12 @@
   }
 
 .search-results__item:last-child {
-    margin-bottom: 0;
+    margin-block-end: 0;
   }
 
 @media (min-width: 62.5rem) {
 
 .search-results__item {
-    margin-bottom: var(--sp3);
+    margin-block-end: var(--sp3);
 }
   }
diff --git a/core/themes/olivero/css/components/site-header.css b/core/themes/olivero/css/components/site-header.css
index aa79fa0e6eb..b240a0adb23 100644
--- a/core/themes/olivero/css/components/site-header.css
+++ b/core/themes/olivero/css/components/site-header.css
@@ -37,7 +37,7 @@
 .site-header {
     /* Necessary to keep the content from jumping up when header transitions to fixed. */
     min-height: var(--site-header-height-wide);
-    border-bottom: solid 1px transparent; /* Will show in Windows high contrast mode. */
+    border-block-end: solid 1px transparent; /* Will show in Windows high contrast mode. */
 }
   }
 
@@ -66,7 +66,7 @@
     body:not(.is-always-mobile-nav) .site-header__fixable.is-fixed {
       position: fixed;
       z-index: 102; /* Appear above body content that is position: relative */
-      top: calc(var(--drupal-displace-offset-top, 0px) - var(--sp4));
+      inset-block-start: calc(var(--drupal-displace-offset-top, 0px) - var(--sp4));
       max-width: var(--max-bg-color);
     }
 }
diff --git a/core/themes/olivero/css/components/skip-link.css b/core/themes/olivero/css/components/skip-link.css
index d8970830188..23a52b2087d 100644
--- a/core/themes/olivero/css/components/skip-link.css
+++ b/core/themes/olivero/css/components/skip-link.css
@@ -25,28 +25,13 @@
 
 /* Width of the entire grid maxes out. */
 
-[dir="ltr"] .skip-link {
-  padding-left: var(--sp);
-}
-
-[dir="rtl"] .skip-link {
-  padding-right: var(--sp);
-}
-
-[dir="ltr"] .skip-link {
-  padding-right: var(--sp);
-}
-
-[dir="rtl"] .skip-link {
-  padding-left: var(--sp);
-}
-
 .skip-link {
   display: block;
   width: 100%;
   max-width: var(--max-bg-color);
-  padding-top: var(--sp0-5);
-  padding-bottom: var(--sp0-5);
+  padding-block: var(--sp0-5);
+  padding-inline-start: var(--sp);
+  padding-inline-end: var(--sp);
   text-decoration: none;
   color: var(--color--white);
   outline: 0;
diff --git a/core/themes/olivero/css/components/table.css b/core/themes/olivero/css/components/table.css
index 31e06ae21de..9dbf7460412 100644
--- a/core/themes/olivero/css/components/table.css
+++ b/core/themes/olivero/css/components/table.css
@@ -27,8 +27,8 @@
 .text-content table,
 .views-table,
 .draggable-table {
-  margin-top: var(--sp2);
-  margin-bottom: var(--sp2);
+  margin-block-start: var(--sp2);
+  margin-block-end: var(--sp2);
   border-spacing: 0;
   color: var(--color-text-neutral-medium);
   border: 0;
@@ -38,16 +38,9 @@
   line-height: var(--sp1-5);
 }
 
-[dir="ltr"] :is(.forum table,.text-content table,.views-table,.draggable-table) caption {
-    text-align: left;
-}
-
-[dir="rtl"] :is(.forum table,.text-content table,.views-table,.draggable-table) caption {
-    text-align: right;
-}
-
 :is(.forum table,.text-content table,.views-table,.draggable-table) caption {
-    margin-bottom: var(--sp1);
+    margin-block-end: var(--sp1);
+    text-align: start;
     color: var(--color-text-neutral-medium);
     font-family: var(--font-serif);
     font-size: 0.875rem;
@@ -56,62 +49,25 @@
   }
 
 :is(.forum table,.text-content table,.views-table,.draggable-table) tr:last-child td {
-        border-bottom: 0;
+        border-block-end: 0;
       }
 
-[dir="ltr"] :is(.forum table,.text-content table,.views-table,.draggable-table) td,[dir="ltr"] :is(.forum table,.text-content table,.views-table,.draggable-table) th {
-    padding-left: 0;
-}
-
-[dir="rtl"] :is(.forum table,.text-content table,.views-table,.draggable-table) td,[dir="rtl"] :is(.forum table,.text-content table,.views-table,.draggable-table) th {
-    padding-right: 0;
-}
-
-[dir="ltr"] :is(.forum table,.text-content table,.views-table,.draggable-table) td,[dir="ltr"] :is(.forum table,.text-content table,.views-table,.draggable-table) th {
-    padding-right: var(--sp1);
-}
-
-[dir="rtl"] :is(.forum table,.text-content table,.views-table,.draggable-table) td,[dir="rtl"] :is(.forum table,.text-content table,.views-table,.draggable-table) th {
-    padding-left: var(--sp1);
-}
-
 :is(.forum table,.text-content table,.views-table,.draggable-table) td,
   :is(.forum table,.text-content table,.views-table,.draggable-table) th {
-    padding-top: var(--sp1);
-    padding-bottom: var(--sp1);
+    padding-block: var(--sp1);
+    padding-inline-start: 0;
+    padding-inline-end: var(--sp1);
     vertical-align: top;
   }
 
-[dir="ltr"] :is(.forum table,.text-content table,.views-table,.draggable-table) th {
-    margin-left: 0;
-}
-
-[dir="rtl"] :is(.forum table,.text-content table,.views-table,.draggable-table) th {
-    margin-right: 0;
-}
-
-[dir="ltr"] :is(.forum table,.text-content table,.views-table,.draggable-table) th {
-    margin-right: 0;
-}
-
-[dir="rtl"] :is(.forum table,.text-content table,.views-table,.draggable-table) th {
-    margin-left: 0;
-}
-
-[dir="ltr"] :is(.forum table,.text-content table,.views-table,.draggable-table) th {
-    text-align: left;
-}
-
-[dir="rtl"] :is(.forum table,.text-content table,.views-table,.draggable-table) th {
-    text-align: right;
-}
-
 :is(.forum table,.text-content table,.views-table,.draggable-table) th {
-    margin-top: 0;
-    margin-bottom: 0;
+    margin-block: 0;
+    margin-inline-start: 0;
+    margin-inline-end: 0;
+    text-align: start;
     letter-spacing: 0.02em;
     color: var(--color-text-neutral-loud);
-    border-bottom: 2px solid var(--color--primary-50);
+    border-block-end: 2px solid var(--color--primary-50);
     font-family: var(--font-sans);
     font-size: 0.875rem;
     line-height: var(--sp);
@@ -119,7 +75,7 @@
 
 :is(.forum table,.text-content table,.views-table,.draggable-table) td {
     white-space: normal;
-    border-bottom: 2px solid var(--color--gray-65);
+    border-block-end: 2px solid var(--color--gray-65);
   }
 
 :is(.forum table,.text-content table,.views-table,.draggable-table) th.checkbox,
@@ -142,7 +98,7 @@
 .sticky-header {
   z-index: 0;
   margin: 0;
-  border-bottom: 0.25rem solid var(--color--primary-50);
+  border-block-end: 0.25rem solid var(--color--primary-50);
 }
 
 /* Properly align VBO checkboxes. */
diff --git a/core/themes/olivero/css/components/tabledrag.css b/core/themes/olivero/css/components/tabledrag.css
index c41780a7368..363cbfe05a9 100644
--- a/core/themes/olivero/css/components/tabledrag.css
+++ b/core/themes/olivero/css/components/tabledrag.css
@@ -45,12 +45,8 @@ a.tabledrag-handle,
   height: 2.25rem;
 }
 
-[dir="ltr"] .draggable a.tabledrag-handle {
-  margin-left: 0;
-}
-
-[dir="rtl"] .draggable a.tabledrag-handle {
-  margin-right: 0;
+.draggable a.tabledrag-handle {
+  margin-inline-start: 0;
 }
 
 a.tabledrag-handle .handle {
@@ -65,25 +61,10 @@ a.tabledrag-handle .handle {
   background-position: 50% 5px;
 }
 
-[dir="ltr"] .touchevents .draggable td {
-  padding-left: 0;
-}
-
-[dir="rtl"] .touchevents .draggable td {
-  padding-right: 0;
-}
-
-[dir="ltr"] .touchevents .draggable td {
-  padding-right: var(--sp0-5);
-}
-
-[dir="rtl"] .touchevents .draggable td {
-  padding-left: var(--sp0-5);
-}
-
 .touchevents .draggable td {
-  padding-top: var(--sp0-5);
-  padding-bottom: var(--sp0-5);
+  padding-block: var(--sp0-5);
+  padding-inline-start: 0;
+  padding-inline-end: var(--sp0-5);
 }
 
 .touchevents .draggable .menu-item__link {
diff --git a/core/themes/olivero/css/components/tabs.css b/core/themes/olivero/css/components/tabs.css
index ae09700fcf4..9a7427d9e5e 100644
--- a/core/themes/olivero/css/components/tabs.css
+++ b/core/themes/olivero/css/components/tabs.css
@@ -20,14 +20,6 @@
 
 /* Breakpoint where tabs switch between vertical and horizontal layouts. */
 
-[dir="ltr"] .tabs {
-  margin-left: 0;
-}
-
-[dir="rtl"] .tabs {
-  margin-right: 0;
-}
-
 .tabs {
   --tabs-height: var(--sp3);
   --tabs-padding-inline: var(--sp1-5);
@@ -46,7 +38,8 @@
   display: flex;
   flex-direction: column;
   width: 100%;
-  margin: 0; /* Override [dir] attribute in base <ul> in compiled CSS. */
+  margin: 0;
+  margin-inline-start: 0; /* Override [dir] attribute in base <ul> in compiled CSS. */
   padding: 0;
   list-style: none;
 }
@@ -62,7 +55,7 @@
 .tabs__tab {
   display: none;
   margin: 0;
-  margin-bottom: calc(-1 * var(--tabs-border-width));
+  margin-block-end: calc(-1 * var(--tabs-border-width));
 }
 
 .tabs__tab.is-active {
@@ -71,17 +64,10 @@
 
 @media (min-width: 43.75rem) {
 
-[dir="ltr"] .tabs__tab {
-    margin-left: calc(-1 * var(--tabs-border-width));
-  }
-
-[dir="rtl"] .tabs__tab {
-    margin-right: calc(-1 * var(--tabs-border-width));
-  }
-
 .tabs__tab {
     display: flex;
-    margin-bottom: 0;
+    margin-block-end: 0;
+    margin-inline-start: calc(-1 * var(--tabs-border-width));
 }
   }
 
@@ -115,10 +101,8 @@ html:not(.js) .tabs__tab {
   flex-grow: 1;
   align-items: center;
   height: var(--tabs-height);
-  padding-top: 0;
-  padding-bottom: 0;
-  padding-left: var(--tabs-padding-inline);
-  padding-right: var(--tabs-padding-inline);
+  padding-block: 0;
+  padding-inline: var(--tabs-padding-inline);
   transition: background-color var(--tabs-transition-duration);
   text-decoration: none;
   letter-spacing: var(--tabs-letter-spacing);
@@ -150,45 +134,23 @@ html:not(.js) .tabs__tab {
      */
   }
 
-[dir="ltr"] .tabs__link.is-active:after {
-      left: calc(-1 * var(--tabs-border-width));
-}
-
-[dir="rtl"] .tabs__link.is-active:after {
-      right: calc(-1 * var(--tabs-border-width));
-}
-
-[dir="ltr"] .tabs__link.is-active:after {
-      border-left: var(--tabs-active-border-size) solid var(--tabs-highlight-color);
-}
-
-[dir="rtl"] .tabs__link.is-active:after {
-      border-right: var(--tabs-active-border-size) solid var(--tabs-highlight-color);
-}
-
 .tabs__link.is-active:after {
       position: absolute;
-      top: calc(-1 * var(--tabs-border-width));
+      inset-block-start: calc(-1 * var(--tabs-border-width));
+      inset-inline-start: calc(-1 * var(--tabs-border-width));
       height: calc(100% + var(--tabs-border-width) * 2);
       content: "";
+      border-inline-start: var(--tabs-active-border-size) solid var(--tabs-highlight-color);
     }
 
 @media (min-width: 43.75rem) {
 
-[dir="ltr"] .tabs__link.is-active:after {
-        border-left: 0;
-  }
-
-[dir="rtl"] .tabs__link.is-active:after {
-        border-right: 0;
-  }
-
 .tabs__link.is-active:after {
-        top: auto;
-        bottom: calc(-1 * var(--tabs-border-width));
+        inset-block: auto calc(-1 * var(--tabs-border-width));
         width: calc(100% + 2 * var(--tabs-border-width));
         height: 0;
-        border-top: var(--tabs-active-border-size) solid var(--tabs-highlight-color);
+        border-block-start: var(--tabs-active-border-size) solid var(--tabs-highlight-color);
+        border-inline-start: 0;
     }
       }
 
@@ -204,23 +166,13 @@ html:not(.js) .tabs__tab {
 
 /* Button that opens and closes primary tabs at narrow viewports. */
 
-[dir="ltr"] .tabs__trigger {
-  margin-left: calc(-1 * var(--tabs-border-width));
-  margin-right: 0;
-}
-
-[dir="rtl"] .tabs__trigger {
-  margin-right: calc(-1 * var(--tabs-border-width));
-  margin-left: 0;
-}
-
 .tabs__trigger {
   display: flex;
   align-items: center;
   justify-content: center;
   width: var(--tabs-height);
-  margin-top: 0;
-  margin-bottom: 0;
+  margin-block: 0;
+  margin-inline: calc(-1 * var(--tabs-border-width)) 0;
   cursor: pointer;
   border: solid var(--tabs-border-width) var(--tabs-border-color);
   background-color: var(--tabs-background-color);
@@ -254,36 +206,29 @@ html:not(.js) .tabs__trigger {
   display: block;
   width: var(--sp);
   height: 0.625rem;
-  margin-top: calc(-2 * var(--tabs-border-width));
-}
-
-[dir="ltr"] .tabs__trigger-icon > span {
-    left: 0;
-}
-
-[dir="rtl"] .tabs__trigger-icon > span {
-    right: 0;
+  margin-block-start: calc(-2 * var(--tabs-border-width));
 }
 
 .tabs__trigger-icon > span {
     position: absolute;
+    inset-inline-start: 0;
     display: block;
     width: 100%;
     transition: transform var(--tabs-transition-duration), opacity var(--tabs-transition-duration), top var(--tabs-transition-duration);
-    border-top: solid 2px var(--tabs-highlight-color);
+    border-block-start: solid 2px var(--tabs-highlight-color);
   }
 
 .tabs__trigger-icon > span:nth-child(1) {
-      top: 0;
+      inset-block-start: 0;
     }
 
 .tabs__trigger[aria-expanded="true"] :is(.tabs__trigger-icon > span:nth-child(1)) {
-        top: calc(50% + 1px);
+        inset-block-start: calc(50% + 1px);
         transform: rotate(45deg);
     }
 
 .tabs__trigger-icon > span:nth-child(2) {
-      top: calc(50% + 1px);
+      inset-block-start: calc(50% + 1px);
     }
 
 .tabs__trigger[aria-expanded="true"] :is(.tabs__trigger-icon > span:nth-child(2)) {
@@ -291,10 +236,10 @@ html:not(.js) .tabs__trigger {
     }
 
 .tabs__trigger-icon > span:nth-child(3) {
-      top: calc(100% + 2px);
+      inset-block-start: calc(100% + 2px);
     }
 
 .tabs__trigger[aria-expanded="true"] :is(.tabs__trigger-icon > span:nth-child(3)) {
-        top: calc(50% + 1px);
+        inset-block-start: calc(50% + 1px);
         transform: rotate(-45deg);
     }
diff --git a/core/themes/olivero/css/components/tags.css b/core/themes/olivero/css/components/tags.css
index 83b1694b418..2e3f52ee9e6 100644
--- a/core/themes/olivero/css/components/tags.css
+++ b/core/themes/olivero/css/components/tags.css
@@ -28,16 +28,9 @@
   font-family: var(--font-sans);
 }
 
-[dir="ltr"] .field--tags__label {
-  margin-right: calc(var(--sp1-5) - (var(--sp0-5) / 2));
-}
-
-[dir="rtl"] .field--tags__label {
-  margin-left: calc(var(--sp1-5) - (var(--sp0-5) / 2));
-}
-
 .field--tags__label {
   margin: 0;
+  margin-inline-end: calc(var(--sp1-5) - (var(--sp0-5) / 2));
   letter-spacing: 0.02em;
   color: var(--color-text-neutral-soft);
   font-size: var(--font-size-s);
@@ -56,89 +49,29 @@
 }
   }
 
-[dir="ltr"] .field--label-inline .field--tags__label {
-  padding-left: 0;
-}
-
-[dir="rtl"] .field--label-inline .field--tags__label {
-  padding-right: 0;
-}
-
-[dir="ltr"] .field--label-inline .field--tags__label {
-  padding-right: 0;
-}
-
-[dir="rtl"] .field--label-inline .field--tags__label {
-  padding-left: 0;
-}
-
 .field--label-inline .field--tags__label {
-  padding-top: 0;
-  padding-bottom: 0;
-}
-
-[dir="ltr"] .field--tags__items {
-  margin-left: calc((var(--sp0-5) / 2) * -1);
-}
-
-[dir="rtl"] .field--tags__items {
-  margin-right: calc((var(--sp0-5) / 2) * -1);
-}
-
-[dir="ltr"] .field--tags__items {
-  margin-right: calc((var(--sp0-5) / 2) * -1);
-}
-
-[dir="rtl"] .field--tags__items {
-  margin-left: calc((var(--sp0-5) / 2) * -1);
-}
-
-[dir="ltr"] .field--tags__items {
-  padding-left: 0;
-}
-
-[dir="rtl"] .field--tags__items {
-  padding-right: 0;
-}
-
-[dir="ltr"] .field--tags__items {
-  padding-right: 0;
-}
-
-[dir="rtl"] .field--tags__items {
-  padding-left: 0;
+  padding-block: 0;
+  padding-inline-start: 0;
+  padding-inline-end: 0;
 }
 
 .field--tags__items {
   display: flex;
   flex-wrap: wrap;
-  margin-top: calc((var(--sp0-5) / 2) * -1);
-  margin-bottom: calc((var(--sp0-5) / 2) * -1);
-  padding-top: 0;
-  padding-bottom: 0;
+  margin-block: calc((var(--sp0-5) / 2) * -1);
+  margin-inline-start: calc((var(--sp0-5) / 2) * -1);
+  margin-inline-end: calc((var(--sp0-5) / 2) * -1);
+  padding-block: 0;
+  padding-inline-start: 0;
+  padding-inline-end: 0;
   list-style: none;
 }
 
-[dir="ltr"] .field--tags__item {
-  margin-left: calc(var(--sp0-5) / 2);
-}
-
-[dir="rtl"] .field--tags__item {
-  margin-right: calc(var(--sp0-5) / 2);
-}
-
-[dir="ltr"] .field--tags__item {
-  margin-right: calc(var(--sp0-5) / 2);
-}
-
-[dir="rtl"] .field--tags__item {
-  margin-left: calc(var(--sp0-5) / 2);
-}
-
 .field--tags__item {
   display: flex;
-  margin-top: calc(var(--sp0-5) / 2);
-  margin-bottom: calc(var(--sp0-5) / 2);
+  margin-block: calc(var(--sp0-5) / 2);
+  margin-inline-start: calc(var(--sp0-5) / 2);
+  margin-inline-end: calc(var(--sp0-5) / 2);
 }
 
 .field--tags__item:nth-last-child(n+2):after {
@@ -159,26 +92,11 @@
   line-height: 1.5;
 }
 
-[dir="ltr"] .node--view-mode-full .field--tags {
-    padding-left: var(--sp2);
-}
-
-[dir="rtl"] .node--view-mode-full .field--tags {
-    padding-right: var(--sp2);
-}
-
-[dir="ltr"] .node--view-mode-full .field--tags {
-    padding-right: var(--sp2);
-}
-
-[dir="rtl"] .node--view-mode-full .field--tags {
-    padding-left: var(--sp2);
-}
-
 .node--view-mode-full .field--tags {
-    margin-top: var(--sp4);
-    margin-bottom: var(--sp4);
-    padding-top: var(--sp1-5);
-    padding-bottom: var(--sp1-5);
+    margin-block-start: var(--sp4);
+    margin-block-end: var(--sp4);
+    padding-block: var(--sp1-5);
+    padding-inline-start: var(--sp2);
+    padding-inline-end: var(--sp2);
     background-color: var(--color--gray-100);
   }
diff --git a/core/themes/olivero/css/components/text-content.css b/core/themes/olivero/css/components/text-content.css
index 8485936113e..225793ff118 100644
--- a/core/themes/olivero/css/components/text-content.css
+++ b/core/themes/olivero/css/components/text-content.css
@@ -65,23 +65,23 @@
     }
 
 .text-content p, .cke_editable p {
-    margin-top: var(--sp);
-    margin-bottom: var(--sp);
+    margin-block-start: var(--sp);
+    margin-block-end: var(--sp);
   }
 
 .text-content p:first-child, .cke_editable p:first-child {
-      margin-top: 0;
+      margin-block-start: 0;
     }
 
 .text-content p:last-child, .cke_editable p:last-child {
-      margin-bottom: 0;
+      margin-block-end: 0;
     }
 
 @media (min-width: 43.75rem) {
 
 .text-content p, .cke_editable p {
-      margin-top: var(--sp2);
-      margin-bottom: var(--sp2);
+      margin-block-start: var(--sp2);
+      margin-block-end: var(--sp2);
   }
     }
 
@@ -89,101 +89,43 @@
     background-color: var(--color--gray-100);
   }
 
-[dir="ltr"] .text-content pre code,[dir="ltr"]  .cke_editable pre code {
-    padding-left: var(--sp);
-}
-
-[dir="rtl"] .text-content pre code,[dir="rtl"]  .cke_editable pre code {
-    padding-right: var(--sp);
-}
-
-[dir="ltr"] .text-content pre code,[dir="ltr"]  .cke_editable pre code {
-    padding-right: var(--sp);
-}
-
-[dir="rtl"] .text-content pre code,[dir="rtl"]  .cke_editable pre code {
-    padding-left: var(--sp);
-}
-
 .text-content pre code, .cke_editable pre code {
     display: block;
     overflow: auto;
-    padding-top: var(--sp);
-    padding-bottom: var(--sp);
+    padding-block: var(--sp);
+    padding-inline-start: var(--sp);
+    padding-inline-end: var(--sp);
     color: var(--color-text-neutral-soft);
   }
 
-[dir="ltr"] .text-content blockquote,[dir="ltr"]  .cke_editable blockquote {
-    margin-left: 0;
-}
-
-[dir="rtl"] .text-content blockquote,[dir="rtl"]  .cke_editable blockquote {
-    margin-right: 0;
-}
-
-[dir="ltr"] .text-content blockquote,[dir="ltr"]  .cke_editable blockquote {
-    margin-right: 0;
-}
-
-[dir="rtl"] .text-content blockquote,[dir="rtl"]  .cke_editable blockquote {
-    margin-left: 0;
-}
-
-[dir="ltr"] .text-content blockquote,[dir="ltr"]  .cke_editable blockquote {
-    padding-left: var(--sp2);
-}
-
-[dir="rtl"] .text-content blockquote,[dir="rtl"]  .cke_editable blockquote {
-    padding-right: var(--sp2);
-}
-
 .text-content blockquote, .cke_editable blockquote {
     position: relative;
-    margin-top: var(--sp2);
-    margin-bottom: var(--sp2);
+    margin-block: var(--sp2);
+    margin-inline-start: 0;
+    margin-inline-end: 0;
+    padding-inline-start: var(--sp2);
     letter-spacing: -0.01em;
     font-family: var(--font-serif);
     font-size: 1.3125rem;
     line-height: var(--sp2);
   }
 
-[dir="ltr"] .text-content blockquote:before,[dir="ltr"]  .cke_editable blockquote:before {
-      left: 0;
-}
-
-[dir="rtl"] .text-content blockquote:before,[dir="rtl"]  .cke_editable blockquote:before {
-      right: 0;
-}
-
 .text-content blockquote:before, .cke_editable blockquote:before {
       position: absolute;
-      top: 0;
+      inset-block-start: 0;
+      inset-inline-start: 0;
       content: "\201C";
       color: var(--color--primary-60);
       font-size: 3.375rem;
     }
 
-[dir="ltr"] .text-content blockquote:after,[dir="ltr"]  .cke_editable blockquote:after {
-      left: 0;
-}
-
-[dir="rtl"] .text-content blockquote:after,[dir="rtl"]  .cke_editable blockquote:after {
-      right: 0;
-}
-
-[dir="ltr"] .text-content blockquote:after,[dir="ltr"]  .cke_editable blockquote:after {
-      margin-left: 0.25rem;
-}
-
-[dir="rtl"] .text-content blockquote:after,[dir="rtl"]  .cke_editable blockquote:after {
-      margin-right: 0.25rem;
-}
-
 .text-content blockquote:after, .cke_editable blockquote:after {
       position: absolute;
-      bottom: 0;
+      inset-block-end: 0;
+      inset-inline-start: 0;
       width: var(--sp0-5);
       height: calc(100% - 1.875rem);
+      margin-inline-start: 0.25rem;
       content: "";
       background: var(--color--gray-100);
     }
diff --git a/core/themes/olivero/css/components/vertical-tabs.css b/core/themes/olivero/css/components/vertical-tabs.css
index dbf7407866e..56116a605d6 100644
--- a/core/themes/olivero/css/components/vertical-tabs.css
+++ b/core/themes/olivero/css/components/vertical-tabs.css
@@ -35,26 +35,12 @@
 }
   }
 
-[dir="ltr"] .vertical-tabs__menu {
-  margin-left: 0;
-}
-
-[dir="rtl"] .vertical-tabs__menu {
-  margin-right: 0;
-}
-
-[dir="ltr"] .vertical-tabs__menu {
-  margin-right: 0;
-}
-
-[dir="rtl"] .vertical-tabs__menu {
-  margin-left: 0;
-}
-
 .vertical-tabs__menu {
   position: relative;
   align-self: flex-start;
   margin: 0;
+  margin-inline-start: 0;
+  margin-inline-end: 0;
   list-style: none;
   border-width: var(--vertical-tabs-menu-border-width);
   border-style: solid;
@@ -70,14 +56,14 @@
   }
 
 .vertical-tabs__panes {
-  margin-top: calc(var(--vertical-tabs-menu-border-width) * -1);
+  margin-block-start: calc(var(--vertical-tabs-menu-border-width) * -1);
 }
 
 @media (min-width: 62.5rem) {
 
 .vertical-tabs__panes {
     width: calc(100% - var(--vertical-tabs-menu-width));
-    margin-top: 0;
+    margin-block-start: 0;
 }
   }
 
@@ -99,29 +85,14 @@
 }
 
 .vertical-tabs__menu-item:nth-child(n+2) {
-  border-top: var(--vertical-tabs-menu-border-width) solid var(--color--gray-95);
-}
-
-[dir="ltr"] .vertical-tabs__menu-item a {
-  padding-left: var(--sp0-75);
-}
-
-[dir="rtl"] .vertical-tabs__menu-item a {
-  padding-right: var(--sp0-75);
-}
-
-[dir="ltr"] .vertical-tabs__menu-item a {
-  padding-right: var(--sp0-75);
-}
-
-[dir="rtl"] .vertical-tabs__menu-item a {
-  padding-left: var(--sp0-75);
+  border-block-start: var(--vertical-tabs-menu-border-width) solid var(--color--gray-95);
 }
 
 .vertical-tabs__menu-item a {
   display: block;
-  padding-top: var(--sp0-5);
-  padding-bottom: var(--sp0-5);
+  padding-block: var(--sp0-5);
+  padding-inline-start: var(--sp0-75);
+  padding-inline-end: var(--sp0-75);
   text-decoration: none;
   color: var(--color-text-primary-loud);
   background-color: var(--color--gray-95);
@@ -139,21 +110,10 @@
 
 @media (min-width: 62.5rem) {
 
-[dir="ltr"] .vertical-tabs__menu-item.is-selected {
-    margin-right: calc(var(--vertical-tabs-menu-border-width) * -1);
-  }
-
-[dir="rtl"] .vertical-tabs__menu-item.is-selected {
-    margin-left: calc(var(--vertical-tabs-menu-border-width) * -1);
-  }
-
-[dir="ltr"] .vertical-tabs__menu-item.is-selected {
-    padding-right: var(--vertical-tabs-menu-border-width);
-  }
-
-[dir="rtl"] .vertical-tabs__menu-item.is-selected {
-    padding-left: var(--vertical-tabs-menu-border-width);
-  }
+.vertical-tabs__menu-item.is-selected {
+    margin-inline-end: calc(var(--vertical-tabs-menu-border-width) * -1);
+    padding-inline-end: var(--vertical-tabs-menu-border-width);
+}
   }
 
 .vertical-tabs__menu-item.is-selected a {
diff --git a/core/themes/olivero/css/components/wide-image.css b/core/themes/olivero/css/components/wide-image.css
index f13c1b94ce9..d745c4889e7 100644
--- a/core/themes/olivero/css/components/wide-image.css
+++ b/core/themes/olivero/css/components/wide-image.css
@@ -23,56 +23,27 @@
 
 /* Width of the entire grid maxes out. */
 
-[dir="ltr"] .wide-image {
-  margin-left: 0;
-}
-
-[dir="rtl"] .wide-image {
-  margin-right: 0;
-}
-
-[dir="ltr"] .wide-image {
-  margin-right: 0;
-}
-
-[dir="rtl"] .wide-image {
-  margin-left: 0;
-}
-
 .wide-image {
-  margin-top: var(--sp0-5);
-  margin-bottom: var(--sp2);
+  margin-block-start: var(--sp0-5);
+  margin-block-end: var(--sp2);
+  margin-inline-start: 0;
+  margin-inline-end: 0;
 }
 
 @media (min-width: 43.75rem) {
 
-[dir="ltr"] .wide-image {
-    margin-left: calc(-1 * ((var(--grid-col-width) + var(--grid-gap))));
-  }
-
-[dir="rtl"] .wide-image {
-    margin-right: calc(-1 * ((var(--grid-col-width) + var(--grid-gap))));
-  }
-
 .wide-image {
     width: calc(var(--grid-col-count) * var(--grid-col-width) + var(--grid-gap-count) * var(--grid-gap));
-    margin-top: var(--sp2);
-    margin-bottom: var(--sp4);
+    margin-block: var(--sp2) var(--sp4);
+    margin-inline-start: calc(-1 * ((var(--grid-col-width) + var(--grid-gap))));
 }
   }
 
 @media (min-width: 62.5rem) {
 
-[dir="ltr"] .wide-image {
-    margin-left: calc(-1 * (var(--grid-col-width) + var(--grid-gap)));
-  }
-
-[dir="rtl"] .wide-image {
-    margin-right: calc(-1 * (var(--grid-col-width) + var(--grid-gap)));
-  }
-
 .wide-image {
     width: calc(12 * var(--grid-col-width) + 11 * var(--grid-gap));
+    margin-inline-start: calc(-1 * (var(--grid-col-width) + var(--grid-gap)));
 }
   }
 
@@ -94,22 +65,8 @@
 
 /* Ensure that image doesn't overlap layout builder sections when editing layouts. */
 
-[dir="ltr"] .layout-builder .wide-image {
-  margin-left: 0;
-}
-
-[dir="rtl"] .layout-builder .wide-image {
-  margin-right: 0;
-}
-
-[dir="ltr"] .layout-builder .wide-image {
-  margin-right: 0;
-}
-
-[dir="rtl"] .layout-builder .wide-image {
-  margin-left: 0;
-}
-
 .layout-builder .wide-image {
   max-width: 100%;
+  margin-inline-start: 0;
+  margin-inline-end: 0;
 }
diff --git a/core/themes/olivero/css/layout/layout-builder-fourcol-section.css b/core/themes/olivero/css/layout/layout-builder-fourcol-section.css
index 008fea1358c..916ce5ab723 100644
--- a/core/themes/olivero/css/layout/layout-builder-fourcol-section.css
+++ b/core/themes/olivero/css/layout/layout-builder-fourcol-section.css
@@ -30,7 +30,7 @@
 
 .layout--fourcol-section > .layout__region {
     flex: 1 0 100%;
-    margin-bottom: var(--grid-gap);
+    margin-block-end: var(--grid-gap);
   }
 
 @media (min-width: 43.75rem) {
@@ -39,7 +39,7 @@
       flex-basis: calc(50% - (var(--grid-gap) * 0.5));
       flex-grow: 0;
       flex-shrink: 0;
-      margin-bottom: 0;
+      margin-block-end: 0;
   }
     }
 
@@ -48,28 +48,18 @@
 @media (min-width: 43.75rem) {
     .layout--fourcol-section > .layout__region--first,
     .layout--fourcol-section > .layout__region--second {
-      margin-bottom: var(--grid-gap);
+      margin-block-end: var(--grid-gap);
     }
 
-    [dir="ltr"] .layout--fourcol-section > .layout__region--first,[dir="ltr"] 
+    .layout--fourcol-section > .layout__region--first,
     .layout--fourcol-section > .layout__region--third {
-      margin-right: calc(var(--grid-gap) * 0.5);
-  }
+      margin-inline-end: calc(var(--grid-gap) * 0.5);
+    }
 
-    [dir="rtl"] .layout--fourcol-section > .layout__region--first,[dir="rtl"] 
-    .layout--fourcol-section > .layout__region--third {
-      margin-left: calc(var(--grid-gap) * 0.5);
-  }
-
-    [dir="ltr"] .layout--fourcol-section > .layout__region--second,[dir="ltr"] 
+    .layout--fourcol-section > .layout__region--second,
     .layout--fourcol-section > .layout__region--fourth {
-      margin-left: calc(var(--grid-gap) * 0.5);
-  }
-
-    [dir="rtl"] .layout--fourcol-section > .layout__region--second,[dir="rtl"] 
-    .layout--fourcol-section > .layout__region--fourth {
-      margin-right: calc(var(--grid-gap) * 0.5);
-  }
+      margin-inline-start: calc(var(--grid-gap) * 0.5);
+    }
   }
 
 /* Four column layout. */
@@ -81,28 +71,19 @@
 
     .layout--fourcol-section > .layout__region--first,
     .layout--fourcol-section > .layout__region--second {
-      margin-bottom: 0;
+      margin-block-end: 0;
     }
 
-    [dir="ltr"] .layout--fourcol-section > .layout__region--first {
-      margin-right: calc(var(--grid-gap) * 0.5);
-  }
-
-    [dir="rtl"] .layout--fourcol-section > .layout__region--first {
-      margin-left: calc(var(--grid-gap) * 0.5);
-  }
+    .layout--fourcol-section > .layout__region--first {
+      margin-inline-end: calc(var(--grid-gap) * 0.5);
+    }
 
     .layout--fourcol-section > .layout__region--second,
     .layout--fourcol-section > .layout__region--third {
-      margin-left: calc(var(--grid-gap) * 0.5);
-      margin-right: calc(var(--grid-gap) * 0.5);
+      margin-inline: calc(var(--grid-gap) * 0.5);
     }
 
-    [dir="ltr"] .layout--fourcol-section > .layout__region--fourth {
-      margin-left: calc(var(--grid-gap) * 0.5);
-  }
-
-    [dir="rtl"] .layout--fourcol-section > .layout__region--fourth {
-      margin-right: calc(var(--grid-gap) * 0.5);
-  }
+    .layout--fourcol-section > .layout__region--fourth {
+      margin-inline-start: calc(var(--grid-gap) * 0.5);
+    }
   }
diff --git a/core/themes/olivero/css/layout/layout-builder-threecol-section.css b/core/themes/olivero/css/layout/layout-builder-threecol-section.css
index c8a3b229ba2..2c2c955bfac 100644
--- a/core/themes/olivero/css/layout/layout-builder-threecol-section.css
+++ b/core/themes/olivero/css/layout/layout-builder-threecol-section.css
@@ -30,7 +30,7 @@
 
 .layout--threecol-section > .layout__region {
     flex: 1 0 100%;
-    margin-bottom: var(--grid-gap);
+    margin-block-end: var(--grid-gap);
   }
 
 @media (min-width: 62.5rem) {
@@ -38,30 +38,22 @@
 .layout--threecol-section > .layout__region {
       flex-grow: 0;
       flex-shrink: 0;
-      margin-bottom: 0;
+      margin-block-end: 0;
   }
     }
 
 @media (min-width: 62.5rem) {
-    [dir="ltr"] .layout--threecol-section > .layout__region--first {
-      margin-right: calc(var(--grid-gap) * 0.5);
-  }
-    [dir="rtl"] .layout--threecol-section > .layout__region--first {
-      margin-left: calc(var(--grid-gap) * 0.5);
-  }
-
-    .layout--threecol-section > .layout__region--second {
-      margin-left: calc(var(--grid-gap) * 0.5);
-      margin-right: calc(var(--grid-gap) * 0.5);
+    .layout--threecol-section > .layout__region--first {
+      margin-inline-end: calc(var(--grid-gap) * 0.5);
     }
 
-    [dir="ltr"] .layout--threecol-section > .layout__region--third {
-      margin-left: calc(var(--grid-gap) * 0.5);
-  }
+    .layout--threecol-section > .layout__region--second {
+      margin-inline: calc(var(--grid-gap) * 0.5);
+    }
 
-    [dir="rtl"] .layout--threecol-section > .layout__region--third {
-      margin-right: calc(var(--grid-gap) * 0.5);
-  }
+    .layout--threecol-section > .layout__region--third {
+      margin-inline-start: calc(var(--grid-gap) * 0.5);
+    }
     .layout--threecol-section--25-50-25 > .layout__region--first,
     .layout--threecol-section--25-50-25 > .layout__region--third {
       flex-basis: calc(25% - (var(--grid-gap) * 0.5));
diff --git a/core/themes/olivero/css/layout/layout-builder-twocol-section.css b/core/themes/olivero/css/layout/layout-builder-twocol-section.css
index efebd154175..c930143aee7 100644
--- a/core/themes/olivero/css/layout/layout-builder-twocol-section.css
+++ b/core/themes/olivero/css/layout/layout-builder-twocol-section.css
@@ -30,7 +30,7 @@
 
 .layout--twocol-section > .layout__region {
     flex: 1 0 100%;
-    margin-bottom: var(--grid-gap);
+    margin-block-end: var(--grid-gap);
   }
 
 @media (min-width: 43.75rem) {
@@ -38,114 +38,54 @@
 .layout--twocol-section > .layout__region {
       flex-grow: 0;
       flex-shrink: 0;
-      margin-bottom: 0;
+      margin-block-end: 0;
   }
     }
 
 @media (min-width: 43.75rem) {
-    [dir="ltr"] .layout--twocol-section--50-50 > .layout__region--first {
-      margin-right: calc(var(--grid-gap) * 0.5);
-  }
-    [dir="rtl"] .layout--twocol-section--50-50 > .layout__region--first {
-      margin-left: calc(var(--grid-gap) * 0.5);
-  }
     .layout--twocol-section--50-50 > .layout__region--first {
       flex-basis: calc(50% - (var(--grid-gap) * 0.5));
+      margin-inline-end: calc(var(--grid-gap) * 0.5);
     }
 
-    [dir="ltr"] .layout--twocol-section--50-50 > .layout__region--second {
-      margin-left: calc(var(--grid-gap) * 0.5);
-  }
-
-    [dir="rtl"] .layout--twocol-section--50-50 > .layout__region--second {
-      margin-right: calc(var(--grid-gap) * 0.5);
-  }
-
     .layout--twocol-section--50-50 > .layout__region--second {
       flex-basis: calc(50% - (var(--grid-gap) * 0.5));
+      margin-inline-start: calc(var(--grid-gap) * 0.5);
     }
-    [dir="ltr"] .layout--twocol-section--33-67 > .layout__region--first {
-      margin-right: calc(var(--grid-gap) * 0.3333);
-  }
-    [dir="rtl"] .layout--twocol-section--33-67 > .layout__region--first {
-      margin-left: calc(var(--grid-gap) * 0.3333);
-  }
     .layout--twocol-section--33-67 > .layout__region--first {
       flex-basis: calc(33.33% - (var(--grid-gap) * 0.3333));
+      margin-inline-end: calc(var(--grid-gap) * 0.3333);
     }
 
-    [dir="ltr"] .layout--twocol-section--33-67 > .layout__region--second {
-      margin-left: calc(var(--grid-gap) * 0.6666);
-  }
-
-    [dir="rtl"] .layout--twocol-section--33-67 > .layout__region--second {
-      margin-right: calc(var(--grid-gap) * 0.6666);
-  }
-
     .layout--twocol-section--33-67 > .layout__region--second {
       flex-basis: calc(66.66% - (var(--grid-gap) * 0.6666));
+      margin-inline-start: calc(var(--grid-gap) * 0.6666);
     }
-    [dir="ltr"] .layout--twocol-section--67-33 > .layout__region--first {
-      margin-right: calc(var(--grid-gap) * 0.6666);
-  }
-    [dir="rtl"] .layout--twocol-section--67-33 > .layout__region--first {
-      margin-left: calc(var(--grid-gap) * 0.6666);
-  }
     .layout--twocol-section--67-33 > .layout__region--first {
       flex-basis: calc(66.66% - (var(--grid-gap) * 0.6666));
+      margin-inline-end: calc(var(--grid-gap) * 0.6666);
     }
 
-    [dir="ltr"] .layout--twocol-section--67-33 > .layout__region--second {
-      margin-left: calc(var(--grid-gap) * 0.3333);
-  }
-
-    [dir="rtl"] .layout--twocol-section--67-33 > .layout__region--second {
-      margin-right: calc(var(--grid-gap) * 0.3333);
-  }
-
     .layout--twocol-section--67-33 > .layout__region--second {
       flex-basis: calc(33.33% - (var(--grid-gap) * 0.3333));
+      margin-inline-start: calc(var(--grid-gap) * 0.3333);
     }
-    [dir="ltr"] .layout--twocol-section--25-75 > .layout__region--first {
-      margin-right: calc(var(--grid-gap) * 0.25);
-  }
-    [dir="rtl"] .layout--twocol-section--25-75 > .layout__region--first {
-      margin-left: calc(var(--grid-gap) * 0.25);
-  }
     .layout--twocol-section--25-75 > .layout__region--first {
       flex-basis: calc(25% - (var(--grid-gap) * 0.25));
+      margin-inline-end: calc(var(--grid-gap) * 0.25);
     }
 
-    [dir="ltr"] .layout--twocol-section--25-75 > .layout__region--second {
-      margin-left: calc(var(--grid-gap) * 0.75);
-  }
-
-    [dir="rtl"] .layout--twocol-section--25-75 > .layout__region--second {
-      margin-right: calc(var(--grid-gap) * 0.75);
-  }
-
     .layout--twocol-section--25-75 > .layout__region--second {
       flex-basis: calc(75% - (var(--grid-gap) * 0.75));
+      margin-inline-start: calc(var(--grid-gap) * 0.75);
     }
-    [dir="ltr"] .layout--twocol-section--75-25 > .layout__region--first {
-      margin-right: calc(var(--grid-gap) * 0.75);
-  }
-    [dir="rtl"] .layout--twocol-section--75-25 > .layout__region--first {
-      margin-left: calc(var(--grid-gap) * 0.75);
-  }
     .layout--twocol-section--75-25 > .layout__region--first {
       flex-basis: calc(75% - (var(--grid-gap) * 0.75));
+      margin-inline-end: calc(var(--grid-gap) * 0.75);
     }
 
-    [dir="ltr"] .layout--twocol-section--75-25 > .layout__region--second {
-      margin-left: calc(var(--grid-gap) * 0.25);
-  }
-
-    [dir="rtl"] .layout--twocol-section--75-25 > .layout__region--second {
-      margin-right: calc(var(--grid-gap) * 0.25);
-  }
-
     .layout--twocol-section--75-25 > .layout__region--second {
       flex-basis: calc(25% - (var(--grid-gap) * 0.25));
+      margin-inline-start: calc(var(--grid-gap) * 0.25);
     }
 }
diff --git a/core/themes/olivero/css/layout/layout-content-narrow.css b/core/themes/olivero/css/layout/layout-content-narrow.css
index 68f0dadeb37..7e147bcb1fa 100644
--- a/core/themes/olivero/css/layout/layout-content-narrow.css
+++ b/core/themes/olivero/css/layout/layout-content-narrow.css
@@ -89,76 +89,42 @@
 
 @media (min-width: 43.75rem) {
 
-[dir="ltr"] .layout--content-narrow.text-content blockquote:before,[dir="ltr"]  .layout--pass--content-narrow > *.text-content blockquote:before,[dir="ltr"]  .layout--content-narrow .text-content blockquote:before,[dir="ltr"]  .layout--pass--content-narrow > * .text-content blockquote:before {
-          left: calc(-1 * (var(--grid-col-width) + var(--grid-gap)));
-  }
-
-[dir="rtl"] .layout--content-narrow.text-content blockquote:before,[dir="rtl"]  .layout--pass--content-narrow > *.text-content blockquote:before,[dir="rtl"]  .layout--content-narrow .text-content blockquote:before,[dir="rtl"]  .layout--pass--content-narrow > * .text-content blockquote:before {
-          right: calc(-1 * (var(--grid-col-width) + var(--grid-gap)));
-  }
-        }
-
-@media (min-width: 43.75rem) {
-
-[dir="ltr"] .layout--content-narrow.text-content blockquote:after,[dir="ltr"]  .layout--pass--content-narrow > *.text-content blockquote:after,[dir="ltr"]  .layout--content-narrow .text-content blockquote:after,[dir="ltr"]  .layout--pass--content-narrow > * .text-content blockquote:after {
-          left: calc(-1 * (var(--grid-col-width) + var(--grid-gap)));
-  }
-
-[dir="rtl"] .layout--content-narrow.text-content blockquote:after,[dir="rtl"]  .layout--pass--content-narrow > *.text-content blockquote:after,[dir="rtl"]  .layout--content-narrow .text-content blockquote:after,[dir="rtl"]  .layout--pass--content-narrow > * .text-content blockquote:after {
-          right: calc(-1 * (var(--grid-col-width) + var(--grid-gap)));
-  }
-
-[dir="ltr"] .layout--content-narrow.text-content blockquote:after,[dir="ltr"]  .layout--pass--content-narrow > *.text-content blockquote:after,[dir="ltr"]  .layout--content-narrow .text-content blockquote:after,[dir="ltr"]  .layout--pass--content-narrow > * .text-content blockquote:after {
-          margin-left: 2px;
-  }
-
-[dir="rtl"] .layout--content-narrow.text-content blockquote:after,[dir="rtl"]  .layout--pass--content-narrow > *.text-content blockquote:after,[dir="rtl"]  .layout--content-narrow .text-content blockquote:after,[dir="rtl"]  .layout--pass--content-narrow > * .text-content blockquote:after {
-          margin-right: 2px;
-  }
-
-.layout--content-narrow.text-content blockquote:after, .layout--pass--content-narrow > *.text-content blockquote:after, .layout--content-narrow .text-content blockquote:after, .layout--pass--content-narrow > * .text-content blockquote:after {
-          width: var(--sp);
-          height: calc(100% - 2.8125rem);
+.layout--content-narrow.text-content blockquote:before, .layout--pass--content-narrow > *.text-content blockquote:before, .layout--content-narrow .text-content blockquote:before, .layout--pass--content-narrow > * .text-content blockquote:before {
+          inset-inline-start: calc(-1 * (var(--grid-col-width) + var(--grid-gap)));
       }
         }
 
 @media (min-width: 43.75rem) {
 
-[dir="ltr"] .layout--content-narrow.text-content blockquote,[dir="ltr"]  .layout--pass--content-narrow > *.text-content blockquote,[dir="ltr"]  .layout--content-narrow .text-content blockquote,[dir="ltr"]  .layout--pass--content-narrow > * .text-content blockquote {
-        padding-left: 0;
-  }
+.layout--content-narrow.text-content blockquote:after, .layout--pass--content-narrow > *.text-content blockquote:after, .layout--content-narrow .text-content blockquote:after, .layout--pass--content-narrow > * .text-content blockquote:after {
+          inset-inline-start: calc(-1 * (var(--grid-col-width) + var(--grid-gap)));
+          width: var(--sp);
+          height: calc(100% - 2.8125rem);
+          margin-inline-start: 2px;
+      }
+        }
 
-[dir="rtl"] .layout--content-narrow.text-content blockquote,[dir="rtl"]  .layout--pass--content-narrow > *.text-content blockquote,[dir="rtl"]  .layout--content-narrow .text-content blockquote,[dir="rtl"]  .layout--pass--content-narrow > * .text-content blockquote {
-        padding-right: 0;
-  }
+@media (min-width: 43.75rem) {
 
 .layout--content-narrow.text-content blockquote, .layout--pass--content-narrow > *.text-content blockquote, .layout--content-narrow .text-content blockquote, .layout--pass--content-narrow > * .text-content blockquote {
         width: calc(10 * var(--grid-col-width) + 9 * var(--grid-gap));
-        margin-top: var(--sp3);
-        margin-bottom: var(--sp3);
+        margin-block: var(--sp3);
+        padding-inline-start: 0;
     }
       }
 
 @media (min-width: 43.75rem) {
 
 .layout--content-narrow.text-content pre, .layout--pass--content-narrow > *.text-content pre, .layout--content-narrow .text-content pre, .layout--pass--content-narrow > * .text-content pre {
-        margin-top: var(--sp3);
-        margin-bottom: var(--sp3);
+        margin-block: var(--sp3);
     }
       }
 
 @media (min-width: 62.5rem) {
 
-[dir="ltr"] .layout--content-narrow.text-content pre,[dir="ltr"]  .layout--pass--content-narrow > *.text-content pre,[dir="ltr"]  .layout--content-narrow .text-content pre,[dir="ltr"]  .layout--pass--content-narrow > * .text-content pre {
-        margin-left: calc(-1 * (var(--grid-col-width) + var(--grid-gap)));
-  }
-
-[dir="rtl"] .layout--content-narrow.text-content pre,[dir="rtl"]  .layout--pass--content-narrow > *.text-content pre,[dir="rtl"]  .layout--content-narrow .text-content pre,[dir="rtl"]  .layout--pass--content-narrow > * .text-content pre {
-        margin-right: calc(-1 * (var(--grid-col-width) + var(--grid-gap)));
-  }
-
 .layout--content-narrow.text-content pre, .layout--pass--content-narrow > *.text-content pre, .layout--content-narrow .text-content pre, .layout--pass--content-narrow > * .text-content pre {
         width: calc(12 * var(--grid-col-width) + 11 * var(--grid-gap));
+        margin-inline-start: calc(-1 * (var(--grid-col-width) + var(--grid-gap)));
     }
       }
 
diff --git a/core/themes/olivero/css/layout/layout-discovery-section-layout.css b/core/themes/olivero/css/layout/layout-discovery-section-layout.css
index 43450fbfd48..28ae2d71399 100644
--- a/core/themes/olivero/css/layout/layout-discovery-section-layout.css
+++ b/core/themes/olivero/css/layout/layout-discovery-section-layout.css
@@ -24,19 +24,19 @@
 /* Width of the entire grid maxes out. */
 
 .layout {
-  margin-bottom: var(--sp);
+  margin-block-end: var(--sp);
 }
 
 @media (min-width: 43.75rem) {
 
 .layout {
-    margin-bottom: var(--sp2);
+    margin-block-end: var(--sp2);
 }
   }
 
 @media (min-width: 62.5rem) {
 
 .layout {
-    margin-bottom: var(--sp3);
+    margin-block-end: var(--sp3);
 }
   }
diff --git a/core/themes/olivero/css/layout/layout-footer.css b/core/themes/olivero/css/layout/layout-footer.css
index 4cc41086ad3..67e2da8ef91 100644
--- a/core/themes/olivero/css/layout/layout-footer.css
+++ b/core/themes/olivero/css/layout/layout-footer.css
@@ -34,36 +34,30 @@
 }
 
 .site-footer__inner {
-  padding-top: var(--sp2);
-  padding-bottom: var(--sp2);
+  padding-block: var(--sp2);
 }
 
 @media (min-width: 75rem) {
 
 .site-footer__inner {
-    padding-top: var(--sp4);
-    padding-bottom: calc(13 * var(--sp));
+    padding-block: var(--sp4) calc(13 * var(--sp));
 }
   }
 
 .region--footer_top__inner > *, .region--footer_bottom__inner > * {
-    margin-bottom: var(--sp2);
+    margin-block-end: var(--sp2);
   }
 
 @media (min-width: 43.75rem) {
 
 .region--footer_top__inner > *, .region--footer_bottom__inner > * {
       flex: 1;
-      margin-bottom: 0;
+      margin-block-end: 0;
   }
 
-      [dir="ltr"] .region--footer_top__inner > *:not(:last-child),[dir="ltr"]  .region--footer_bottom__inner > *:not(:last-child) {
-        margin-right: var(--sp2);
-  }
-
-      [dir="rtl"] .region--footer_top__inner > *:not(:last-child),[dir="rtl"]  .region--footer_bottom__inner > *:not(:last-child) {
-        margin-left: var(--sp2);
-  }
+      .region--footer_top__inner > *:not(:last-child), .region--footer_bottom__inner > *:not(:last-child) {
+        margin-inline-end: var(--sp2);
+      }
     }
 
 @media (min-width: 43.75rem) {
diff --git a/core/themes/olivero/css/layout/layout-views-grid.css b/core/themes/olivero/css/layout/layout-views-grid.css
index a5805240553..2b20fe359cc 100644
--- a/core/themes/olivero/css/layout/layout-views-grid.css
+++ b/core/themes/olivero/css/layout/layout-views-grid.css
@@ -47,14 +47,14 @@
 }
 
 .views-view-grid--vertical {
-  margin-bottom: calc(-1 * var(--views-grid--layout-gap)); /* Offset the bottom row's padding. */
+  margin-block-end: calc(-1 * var(--views-grid--layout-gap)); /* Offset the bottom row's padding. */
   column-width: var(--views-grid-item--min-width);
   column-count: var(--views-grid--column-count);
   column-gap: var(--views-grid--layout-gap);
 }
 
 .views-view-grid--vertical .views-view-grid__item > * {
-      padding-bottom: var(--views-grid--layout-gap);
+      padding-block-end: var(--views-grid--layout-gap);
       page-break-inside: avoid;
       break-inside: avoid;
     }
diff --git a/core/themes/olivero/css/layout/layout.css b/core/themes/olivero/css/layout/layout.css
index 58ce897d3f8..a38c4d12aff 100644
--- a/core/themes/olivero/css/layout/layout.css
+++ b/core/themes/olivero/css/layout/layout.css
@@ -26,8 +26,7 @@
 .container {
   width: 100%;
   max-width: var(--max-width);
-  padding-left: var(--container-padding);
-  padding-right: var(--container-padding);
+  padding-inline: var(--container-padding);
 
   /* This fixes an issue where if the toolbar is open in vertical mode, and
    * the mobile navigation is open, the "close" button gets pushed outside of
@@ -66,26 +65,19 @@ body.is-fixed .container {
 
 @media (min-width: 75rem) {
 
-[dir="ltr"] .main-content {
-    margin-right: auto;
-  }
-
-[dir="rtl"] .main-content {
-    margin-left: auto;
-  }
-
 .main-content {
     width: calc(100% - var(--content-left));
+    margin-inline-end: auto;
 }
   }
 
 .main-content__container {
-  padding-top: var(--sp3);
+  padding-block-start: var(--sp3);
 }
 
 @media (min-width: 43.75rem) {
 
 .main-content__container {
-    padding-top: var(--sp5);
+    padding-block-start: var(--sp5);
 }
   }
diff --git a/core/themes/olivero/css/layout/region-content-below.css b/core/themes/olivero/css/layout/region-content-below.css
index 67dfb3e3782..de5c9a6fe18 100644
--- a/core/themes/olivero/css/layout/region-content-below.css
+++ b/core/themes/olivero/css/layout/region-content-below.css
@@ -30,29 +30,17 @@
     flex-wrap: wrap;
 }
 
-    [dir="ltr"] .region--content-below > * {
-      margin-right: var(--grid-gap);
-}
-
-    [dir="rtl"] .region--content-below > * {
-      margin-left: var(--grid-gap);
-}
-
     .region--content-below > * {
       flex-basis: calc(50% - (var(--grid-gap) / 2));
       flex-grow: 1;
       flex-shrink: 0;
+      margin-inline-end: var(--grid-gap);
     }
 
-      [dir="ltr"] .region--content-below > *:nth-child(2n),[dir="ltr"] 
+      .region--content-below > *:nth-child(2n),
       .region--content-below > *:last-child {
-        margin-right: 0;
-}
-
-      [dir="rtl"] .region--content-below > *:nth-child(2n),[dir="rtl"] 
-      .region--content-below > *:last-child {
-        margin-left: 0;
-}
+        margin-inline-end: 0;
+      }
   }
 
 @media (min-width: 43.75rem) {
@@ -60,23 +48,13 @@
       flex-basis: calc(33.33% - (var(--grid-gap) * 0.667));
     }
 
-      [dir="ltr"] .region--content-below > *:nth-child(2n),[dir="ltr"] 
+      .region--content-below > *:nth-child(2n),
       .region--content-below > *:last-child {
-        margin-right: var(--grid-gap);
-}
+        margin-inline-end: var(--grid-gap);
+      }
 
-      [dir="rtl"] .region--content-below > *:nth-child(2n),[dir="rtl"] 
+      .region--content-below > *:nth-child(3n),
       .region--content-below > *:last-child {
-        margin-left: var(--grid-gap);
-}
-
-      [dir="ltr"] .region--content-below > *:nth-child(3n),[dir="ltr"] 
-      .region--content-below > *:last-child {
-        margin-right: 0;
-}
-
-      [dir="rtl"] .region--content-below > *:nth-child(3n),[dir="rtl"] 
-      .region--content-below > *:last-child {
-        margin-left: 0;
-}
+        margin-inline-end: 0;
+      }
   }
diff --git a/core/themes/olivero/css/layout/region-content.css b/core/themes/olivero/css/layout/region-content.css
index 6765571f63a..1fd9391f106 100644
--- a/core/themes/olivero/css/layout/region-content.css
+++ b/core/themes/olivero/css/layout/region-content.css
@@ -24,19 +24,19 @@
 /* Width of the entire grid maxes out. */
 
 .region--content {
-  margin-bottom: var(--sp);
+  margin-block-end: var(--sp);
 }
 
 @media (min-width: 43.75rem) {
 
 .region--content {
-    margin-bottom: var(--sp2);
+    margin-block-end: var(--sp2);
 }
   }
 
 @media (min-width: 62.5rem) {
 
 .region--content {
-    margin-bottom: var(--sp3);
+    margin-block-end: var(--sp3);
 }
   }
diff --git a/core/themes/olivero/css/layout/region-hero.css b/core/themes/olivero/css/layout/region-hero.css
index 86b1c6866de..45812544c09 100644
--- a/core/themes/olivero/css/layout/region-hero.css
+++ b/core/themes/olivero/css/layout/region-hero.css
@@ -24,5 +24,5 @@
 /* Width of the entire grid maxes out. */
 
 .region--hero > *:last-child {
-    margin-bottom: 0;
+    margin-block-end: 0;
   }
diff --git a/core/themes/olivero/css/layout/region-secondary-menu.css b/core/themes/olivero/css/layout/region-secondary-menu.css
index 1a89f5a8d30..8d0219f3c98 100644
--- a/core/themes/olivero/css/layout/region-secondary-menu.css
+++ b/core/themes/olivero/css/layout/region-secondary-menu.css
@@ -25,12 +25,12 @@
 
 .region--secondary-menu {
   display: flex;
-  margin-top: var(--sp2);
-  margin-bottom: var(--sp2);
+  margin-block-start: var(--sp2);
+  margin-block-end: var(--sp2);
 }
 
 .region--secondary-menu > * {
-    margin-bottom: 0;
+    margin-block-end: 0;
   }
 
 @media (min-width: 75rem) {
diff --git a/core/themes/olivero/css/layout/region.css b/core/themes/olivero/css/layout/region.css
index 55138d93f17..1d06929baf4 100644
--- a/core/themes/olivero/css/layout/region.css
+++ b/core/themes/olivero/css/layout/region.css
@@ -24,19 +24,19 @@
 /* Width of the entire grid maxes out. */
 
 .region > * {
-  margin-bottom: var(--sp);
+  margin-block-end: var(--sp);
 }
 
 @media (min-width: 43.75rem) {
 
 .region > * {
-    margin-bottom: var(--sp2);
+    margin-block-end: var(--sp2);
 }
   }
 
 @media (min-width: 62.5rem) {
 
 .region > * {
-    margin-bottom: var(--sp3);
+    margin-block-end: var(--sp3);
 }
   }
diff --git a/core/themes/olivero/css/layout/social-bar.css b/core/themes/olivero/css/layout/social-bar.css
index 71687b4ec71..a908d6d3a9e 100644
--- a/core/themes/olivero/css/layout/social-bar.css
+++ b/core/themes/olivero/css/layout/social-bar.css
@@ -33,70 +33,33 @@
 }
   }
 
-[dir="ltr"] .social-bar__inner {
-  padding-left: var(--sp);
-}
-
-[dir="rtl"] .social-bar__inner {
-  padding-right: var(--sp);
-}
-
-[dir="ltr"] .social-bar__inner {
-  padding-right: var(--sp);
-}
-
-[dir="rtl"] .social-bar__inner {
-  padding-left: var(--sp);
-}
-
 .social-bar__inner {
   position: relative;
-  padding-top: var(--sp0-5);
-  padding-bottom: var(--sp0-5);
+  padding-block: var(--sp0-5);
+  padding-inline-start: var(--sp);
+  padding-inline-end: var(--sp);
 }
 
 @media (min-width: 75rem) {
 
-[dir="ltr"] .social-bar__inner {
-    padding-left: 0;
-}
-
-[dir="rtl"] .social-bar__inner {
-    padding-right: 0;
-}
-
-[dir="ltr"] .social-bar__inner {
-    padding-right: 0;
-}
-
-[dir="rtl"] .social-bar__inner {
-    padding-left: 0;
-}
-
 .social-bar__inner {
     position: relative;
     width: var(--content-left);
-    padding-top: calc(5 * var(--sp));
-    padding-bottom: calc(5 * var(--sp));
-}
-
-    [dir="ltr"] .social-bar__inner.is-fixed {
-      left: 0;
-}
-
-    [dir="rtl"] .social-bar__inner.is-fixed {
-      right: 0;
+    padding-block: calc(5 * var(--sp));
+    padding-inline-start: 0;
+    padding-inline-end: 0;
 }
 
     .social-bar__inner.is-fixed {
       position: fixed;
-      top: var(--sp6);
+      inset-block-start: var(--sp6);
+      inset-inline-start: 0;
       height: calc(100vh - 6 * var(--sp));
     }
   }
 
 .rotate > * {
-    margin-bottom: var(--sp2);
+    margin-block-end: var(--sp2);
   }
 
 @media (min-width: 75rem) {
@@ -104,56 +67,32 @@
 .rotate > * {
       display: flex;
       align-items: center;
-      margin-bottom: 0;
+      margin-block-end: 0;
   }
 
-      [dir="ltr"] .rotate > *:not(:first-child) {
-        margin-right: var(--sp2);
-}
-
-      [dir="rtl"] .rotate > *:not(:first-child) {
-        margin-left: var(--sp2);
-}
+      .rotate > *:not(:first-child) {
+        margin-inline-end: var(--sp2);
+      }
     }
 
 @media (min-width: 75rem) {
 
-[dir="ltr"] .rotate .contextual {
-      left: 100%;
-      right: auto;
-}
-
-[dir="rtl"] .rotate .contextual {
-      right: 100%;
-      left: auto;
-}
-
 .rotate .contextual {
+      inset-inline: 100% auto;
       transform: rotate(90deg); /* LTR */
       transform-origin: top left; /* LTR */
   }
 
-      [dir="ltr"] .rotate .contextual .trigger {
-        float: left;
-}
-
-      [dir="rtl"] .rotate .contextual .trigger {
-        float: right;
-}
+      .rotate .contextual .trigger {
+        float: inline-start;
+      }
     }
 
 @media (min-width: 75rem) {
 
-[dir="ltr"] .rotate {
-    left: 50%;
-}
-
-[dir="rtl"] .rotate {
-    right: 50%;
-}
-
 .rotate {
     position: absolute;
+    inset-inline-start: 50%;
     display: flex;
     flex-direction: row-reverse;
     width: 100vh;
diff --git a/core/themes/olivero/css/layout/views.css b/core/themes/olivero/css/layout/views.css
index 135d635753d..5dd4c186722 100644
--- a/core/themes/olivero/css/layout/views.css
+++ b/core/themes/olivero/css/layout/views.css
@@ -24,16 +24,16 @@
 /* Width of the entire grid maxes out. */
 
 .view > * {
-    margin-bottom: var(--sp2);
+    margin-block-end: var(--sp2);
   }
 
 .view > *:last-child {
-      margin-bottom: 0;
+      margin-block-end: 0;
     }
 
 @media (min-width: 43.75rem) {
 
 .view > * {
-      margin-bottom: var(--sp3);
+      margin-block-end: var(--sp3);
   }
     }
diff --git a/core/themes/olivero/css/theme/filter.theme.css b/core/themes/olivero/css/theme/filter.theme.css
index c7987c77565..132478f0ab9 100644
--- a/core/themes/olivero/css/theme/filter.theme.css
+++ b/core/themes/olivero/css/theme/filter.theme.css
@@ -28,7 +28,7 @@
  */
 
 .text-full > .form-item {
-  margin-bottom: 0;
+  margin-block-end: 0;
 }
 
 .form-element--editor-format {
@@ -36,25 +36,16 @@
 }
 
 .filter-wrapper {
-  margin-top: var(--sp1);
-  margin-bottom: var(--sp0-5);
+  margin-block: var(--sp1) var(--sp0-5);
 }
 
 .filter-wrapper .form-item {
   margin: 0;
 }
 
-[dir="ltr"] .filter-help {
-  float: right;
-}
-
-[dir="rtl"] .filter-help {
-  float: left;
-}
-
 .filter-help {
-  padding-top: var(--sp0-5);
-  padding-bottom: var(--sp0-5);
+  float: inline-end;
+  padding-block: var(--sp0-5);
   font-size: var(--font-size-xxs);
 }
 
@@ -65,8 +56,7 @@
  */
 
 .compose-tips__item {
-  margin-top: var(--sp1-5);
-  margin-bottom: var(--sp1-5);
+  margin-block: var(--sp1-5);
 }
 
 /**
@@ -74,14 +64,13 @@
  */
 
 .filter-guidelines__item {
-  margin-top: var(--sp1);
+  margin-block-start: var(--sp1);
   font-size: var(--font-size-s);
   line-height: var(--line-height-s);
 }
 
 .filter-guidelines p {
-  margin-top: var(--sp0-25);
-  margin-bottom: 0;
+  margin-block: var(--sp0-25) 0;
 }
 
 /**
@@ -92,16 +81,14 @@
  */
 
 .filter-tips--long {
-  margin-bottom: var(--sp1-5);
+  margin-block-end: var(--sp1-5);
 }
 
 .filter-tips__item,
 .filter-tips--long p {
-  margin-top: var(--sp0-75);
-  margin-bottom: var(--sp0-75);
+  margin-block: var(--sp0-75);
 }
 
 .filter-tips__item--short {
-  margin-top: var(--sp0-25);
-  margin-bottom: 0;
+  margin-block: var(--sp0-25) 0;
 }
diff --git a/core/yarn.lock b/core/yarn.lock
index ed0d03c15fe..06b94528b5d 100644
--- a/core/yarn.lock
+++ b/core/yarn.lock
@@ -1376,15 +1376,10 @@ camelcase@^6.0.0, camelcase@^6.2.0:
   resolved "https://registry.yarnpkg.com/camelcase/-/camelcase-6.3.0.tgz#5685b95eb209ac9c0c177467778c9c84df58ba9a"
   integrity sha512-Gmy6FhYlCY7uOElZUSbxo2UCDH8owEk996gkbrpsgGtrJLM3J7jGxl9Ic7Qwwj4ivOE5AWZWRMecDdF7hqGjFA==
 
-caniuse-lite@^1.0.30001370:
-  version "1.0.30001390"
-  resolved "https://registry.yarnpkg.com/caniuse-lite/-/caniuse-lite-1.0.30001390.tgz#158a43011e7068ef7fc73590e9fd91a7cece5e7f"
-  integrity sha512-sS4CaUM+/+vqQUlCvCJ2WtDlV81aWtHhqeEVkLokVJJa3ViN4zDxAGfq9R8i1m90uGHxo99cy10Od+lvn3hf0g==
-
-caniuse-lite@^1.0.30001394:
-  version "1.0.30001397"
-  resolved "https://registry.yarnpkg.com/caniuse-lite/-/caniuse-lite-1.0.30001397.tgz#010d9d56e3b8abcd8df261d0a94b22426271a15f"
-  integrity sha512-SW9N2TbCdLf0eiNDRrrQXx2sOkaakNZbCjgNpPyMJJbiOrU5QzMIrXOVMRM1myBXTD5iTkdrtU/EguCrBocHlA==
+caniuse-lite@^1.0.30001370, caniuse-lite@^1.0.30001394:
+  version "1.0.30001412"
+  resolved "https://registry.npmjs.org/caniuse-lite/-/caniuse-lite-1.0.30001412.tgz"
+  integrity sha512-+TeEIee1gS5bYOiuf+PS/kp2mrXic37Hl66VY6EAfxasIk5fELTktK2oOezYed12H8w7jt3s512PpulQidPjwA==
 
 chai-nightwatch@0.5.3:
   version "0.5.3"