WordPress · westonruter · May 20, 2026 · May 21, 2026 · May 21, 2026
diff --git a/src/wp-admin/css/view-transitions.css b/src/wp-admin/css/view-transitions.css
@@ -3,7 +3,40 @@
 		navigation: auto;
 	}
 
+	/*
+	 * Give each top-level menu item its own view transition name — its id,
+	 * such as "menu-posts" — so each one is captured as an independent group
+	 * and animates from its old position and size to its new ones across a
+	 * navigation. This produces the accordion effect: the previously open
+	 * section collapses as the newly current one expands, instead of the
+	 * whole menu simply cross-fading. attr() falls back to "none" for any
+	 * item whose id is missing or is not a valid custom identifier. The
+	 * shared wp-menu-top class lets the image-pair rule below address every
+	 * menu-top group at once.
+	 */
 	#adminmenu > .menu-top {
 		view-transition-name: attr(id type(<custom-ident>), none);
+		view-transition-class: wp-menu-top;
+	}
+
+	/*
+	 * Name the collapse button too, so it slides into place with the menu
+	 * items instead of cross-fading as part of the page root.
+	 */
+	#collapse-menu {
+		view-transition-name: collapse-menu;
+	}
+
+	/*
+	 * Clip each menu-top's snapshot to its animating group box. By default a
+	 * captured snapshot keeps its full intrinsic height, so the new (expanded)
+	 * submenu paints at full height from the first frame and overlaps the
+	 * items below while they are still sliding down. Clipping the image pair
+	 * to the group — whose height animates from the link row to the full
+	 * expanded height — makes the submenu wipe open, and closed in reverse,
+	 * in step with those items.
+	 */
+	::view-transition-image-pair(.wp-menu-top) {
+		overflow: clip;
 	}
 }
diff --git a/src/wp-includes/default-filters.php b/src/wp-includes/default-filters.php
@@ -603,6 +603,7 @@
 add_action( 'admin_enqueue_scripts', 'wp_common_block_scripts_and_styles' );
 add_action( 'admin_enqueue_scripts', 'wp_enqueue_command_palette_assets' );
 add_action( 'admin_enqueue_scripts', 'wp_enqueue_view_transitions_admin_css' );
+add_action( 'admin_head', 'wp_print_view_transitions_render_blocking_link' );
 add_action( 'enqueue_block_assets', 'wp_enqueue_classic_theme_styles' );
 add_action( 'enqueue_block_assets', 'wp_enqueue_registered_block_scripts_and_styles' );
 add_action( 'enqueue_block_assets', 'enqueue_block_styles_assets', 30 );

diff --git a/src/wp-includes/view-transitions.php b/src/wp-includes/view-transitions.php
@@ -26,5 +26,26 @@ function wp_enqueue_view_transitions_admin_css(): void {
 function wp_get_view_transitions_admin_css(): string {
 	$affix = SCRIPT_DEBUG ? '' : '.min';
 	$path  = ABSPATH . "wp-admin/css/view-transitions{$affix}.css";
-	return file_get_contents( $path );
+	return (string) file_get_contents( $path );
+}
+
+/**
+ * Prints a render-blocking expectation so View Transitions capture a fully parsed admin page.
+ *
+ * A cross-document view transition snapshots the incoming page at its first render, which can
+ * happen before the `<body>` has finished parsing. The snapshot would then capture a partially
+ * built page — for example an incomplete admin menu — and the transition animates to or from
+ * the wrong state.
+ *
+ * The `expect` link blocks the first render until an element near the end of the body is
+ * parsed, so the snapshot is always taken of a complete page. The media query limits the
+ * (small) first-render delay to when view transitions actually run, matching the
+ * `@view-transition` rule in view-transitions.css.
+ *
+ * @since 7.0.1
+ *
+ * @link https://html.spec.whatwg.org/multipage/links.html#link-type-expect
+ */
+function wp_print_view_transitions_render_blocking_link(): void {
+	echo '<link rel="expect" href="#wpfooter" blocking="render" media="(prefers-reduced-motion: no-preference)">' . "\n";
 }