docs-v2/assets/styles/sidebar-open.scss

// Default state of having the sidebar open.

.sidebar {
  transition: all .2s;
  .search-and-nav-toggle,
  #nav-tree {
    opacity: 1;
    transition: all .3s;
    transition-delay: .1s;
  }
}

#search-btn {
  opacity: 0;
}