diff --git a/tests/Browser/NavigationTest.php b/tests/Browser/NavigationTest.php
index 0684af4e..5b03570d 100644
--- a/tests/Browser/NavigationTest.php
+++ b/tests/Browser/NavigationTest.php
@@ -306,6 +306,13 @@ function navigationExtrasProbe(): mixed
                     <button type="button" id="open-hiding-rail" x-data x-on:click="$store.rail.show()">Open navigation</button>
                 </div>
 
+                <div id="adaptive-hiding-rail" style="display: flex">
+                    <x-navigation-rail mode="adaptive" hide-when-collapsed>
+                        <x-navigation-rail-item label="Canvas" icon="brush" link="#a" no-wire-navigate active />
+                        <x-navigation-rail-item label="Layers" icon="layers" link="#b" no-wire-navigate />
+                    </x-navigation-rail>
+                </div>
+
                 <div style="height: 250vh"></div>
 
                 <x-toast />
@@ -337,8 +344,8 @@ it('hides the bar on a scroll down and never while a pinned snackbar is on scree
     $page->script('window.scrollTo(0, 0)');
     $page->assertScript("{$hidden} === false");
 
-    $page->script("materialToast('Pinned', { sticky: true })")
-        ->assertScript("document.querySelector('[data-md-toast-snackbar]')?.textContent.includes('Pinned')");
+    $page->script("materialToast('Pinned', { sticky: true })");
+    $page->assertScript("document.querySelector('[data-md-toast-snackbar]')?.textContent.includes('Pinned')");
 
     $page->script('window.scrollTo(0, 400)');
     $page->assertScript("{$hidden} === false")
@@ -369,3 +376,36 @@ it('takes a rail out of the layout entirely when it hides collapsed, and back ov
         ->assertScript("getComputedStyle(document.querySelector('#hiding-rail [data-md-navigation-rail-panel]')).display === 'flex'")
         ->assertNoJavaScriptErrors();
 });
+
+it('takes an adaptive rail out of the layout across the expanded class when it hides collapsed, standing again from large', function () {
+    $page = navigationExtrasProbe();
+    $rail = "document.querySelector('#adaptive-hiding-rail [data-md-navigation-rail]')";
+    $railWidth = "Math.round({$rail}.getBoundingClientRect().width)";
+
+    // `medium` (600-839): the window collapses the rail, not the visitor, so M3's "collapsed rail
+    // may never hide" holds even with hide-when-collapsed set — it stays at its collapsed width.
+    $page->resize(839, 900)
+        ->assertScript("{$railWidth} === 96")
+        ->assertScript("! {$rail}.hasAttribute('data-md-open')")
+        ->assertScript("document.documentElement.hasAttribute('data-rail-auto')")
+        ->assertNoJavaScriptErrors();
+
+    // `expanded` (840-1199): nothing chosen yet, so the rail is away rather than shown collapsed.
+    $page->resize(840, 900)
+        ->assertScript("{$railWidth} === 0")
+        ->assertScript("! {$rail}.hasAttribute('data-md-open')")
+        ->assertScript("document.documentElement.hasAttribute('data-rail-auto')")
+        ->assertNoJavaScriptErrors();
+
+    $page->resize(1199, 900)
+        ->assertScript("{$railWidth} === 0")
+        ->assertScript("document.documentElement.hasAttribute('data-rail-auto')");
+
+    // `large` (1200+): M3 starts an adaptive rail expanded by default, so it stands in the layout
+    // again rather than staying away.
+    $page->resize(1200, 900)
+        ->assertScript("{$railWidth} === 256")
+        ->assertScript("! {$rail}.hasAttribute('data-md-open')")
+        ->assertScript("document.documentElement.hasAttribute('data-rail-auto')")
+        ->assertNoJavaScriptErrors();
+});