diff --git a/templates/user/heatmap.tmpl b/templates/user/heatmap.tmpl
index b604b929a3..6186edd4dd 100644
--- a/templates/user/heatmap.tmpl
+++ b/templates/user/heatmap.tmpl
@@ -1,4 +1,5 @@
 {{if .HeatmapData}}
+<div class="activity-heatmap-container">
 	<div id="user-heatmap" class="is-loading"
 		data-heatmap-data="{{JsonUtils.EncodeToString .HeatmapData}}"
 		data-locale-total-contributions="{{ctx.Locale.Tr "heatmap.number_of_contributions_in_the_last_12_months" (ctx.Locale.PrettyNumber .HeatmapTotalContributions)}}"
@@ -6,5 +7,6 @@
 		data-locale-more="{{ctx.Locale.Tr "heatmap.more"}}"
 		data-locale-less="{{ctx.Locale.Tr "heatmap.less"}}"
 	></div>
-	<div class="divider"></div>
+</div>
+<div class="divider"></div>
 {{end}}
diff --git a/web_src/css/features/heatmap.css b/web_src/css/features/heatmap.css
index c064590c46..e40adf1fe4 100644
--- a/web_src/css/features/heatmap.css
+++ b/web_src/css/features/heatmap.css
@@ -4,23 +4,44 @@
   position: relative;
 }
 
-/* before the Vue component is mounted, show a loading indicator with dummy size */
-/* the ratio is guesswork, see https://github.com/razorness/vue3-calendar-heatmap/issues/26 */
-#user-heatmap.is-loading {
-  aspect-ratio: 5.415; /* the size is about 790 x 145 */
+.activity-heatmap-container {
+  container-type: inline-size;
 }
-.user.profile #user-heatmap.is-loading {
-  aspect-ratio: 5.645; /* the size is about 953 x 169 */
+
+@container (width > 0) {
+  #user-heatmap {
+    /* Set element to fixed height so that it does not resize after load. The calculation is complex
+       because the element does not scale with a fixed aspect ratio. */
+    height: calc((100cqw / 5) - (100cqw / 25) + 20px);
+  }
+}
+
+/* Fallback height adjustment above for browsers that don't support container queries */
+@supports not (container-type: inline-size) {
+  /* Before the Vue component is mounted, show a loading indicator with dummy size */
+  /* The ratio is guesswork for legacy browsers, new browsers use the "@container" approach above  */
+  #user-heatmap.is-loading {
+    aspect-ratio: 5.4823972051; /* the size is about 816 x 148.84 */
+  }
+  .user.profile #user-heatmap.is-loading {
+    aspect-ratio: 5.6290608387; /* the size is about 953 x 169.3 */
+  }
 }
 
 #user-heatmap text {
   fill: currentcolor !important;
 }
 
+/* root legend */
+#user-heatmap .vch__container > .vch__legend {
+  display: flex;
+  font-size: 11px;
+  justify-content: space-between;
+}
+
 /* for the "Less" and "More" legend */
 #user-heatmap .vch__legend .vch__legend {
   display: flex;
-  font-size: 11px;
   align-items: center;
   justify-content: right;
 }
@@ -34,25 +55,3 @@
 #user-heatmap .vch__day__square:hover {
   outline: 1.5px solid var(--color-text);
 }
-
-/* move the "? contributions in the last ? months" text from top to bottom */
-#user-heatmap .total-contributions {
-  font-size: 11px;
-  position: absolute;
-  bottom: 0;
-  left: 25px;
-}
-
-@media (max-width: 1200px) {
-  #user-heatmap .total-contributions {
-    left: 21px;
-  }
-}
-
-@media (max-width: 1000px) {
-  #user-heatmap .total-contributions {
-    font-size: 10px;
-    left: 17px;
-    bottom: -4px;
-  }
-}
diff --git a/web_src/js/components/ActivityHeatmap.vue b/web_src/js/components/ActivityHeatmap.vue
index 296cb61cff..d805817630 100644
--- a/web_src/js/components/ActivityHeatmap.vue
+++ b/web_src/js/components/ActivityHeatmap.vue
@@ -53,9 +53,6 @@ function handleDayClick(e: Event & {date: Date}) {
 }
 </script>
 <template>
-  <div class="total-contributions">
-    {{ locale.textTotalContributions }}
-  </div>
   <calendar-heatmap
     :locale="locale.heatMapLocale"
     :no-data-text="locale.noDataText"
@@ -65,5 +62,7 @@ function handleDayClick(e: Event & {date: Date}) {
     :range-color="colorRange"
     @day-click="handleDayClick($event)"
     :tippy-props="{theme: 'tooltip'}"
-  />
+  >
+    <template #vch__legend-left>{{ locale.textTotalContributions }}</template>
+  </calendar-heatmap>
 </template>