diff --git a/website/js/notification-manager.js b/website/js/notification-manager.js
index 8ac61c715..739417f77 100644
--- a/website/js/notification-manager.js
+++ b/website/js/notification-manager.js
@@ -139,7 +139,7 @@ class NotificationManager {
         toast.style.transform = 'translateY(-20px)';
 
         // Respect reduced motion preference
-        const reduceMotion = window.matchMedia && window.matchMedia('(prefers-reduced-motion: reduce)').matches;
+        const reduceMotion = window.matchMedia?.('(prefers-reduced-motion: reduce)')?.matches;
         if (reduceMotion) {
             toast.style.transition = 'none';
         }
diff --git a/website/test/setup.js b/website/test/setup.js
index fb5ba73be..15d1e1d19 100644
--- a/website/test/setup.js
+++ b/website/test/setup.js
@@ -33,12 +33,21 @@ if (typeof navigator !== 'undefined') {
   });
 }
 
-// Optional: matchMedia stub
+// Enhanced matchMedia mock for proper test environment support
+// Only override if matchMedia is not already available (e.g., in certain test environments)
 if (!window.matchMedia) {
-  window.matchMedia = vi.fn().mockReturnValue({
-    matches: false,
-    addEventListener: vi.fn(),
-    removeEventListener: vi.fn()
+  Object.defineProperty(window, 'matchMedia', {
+    writable: true,
+    value: vi.fn().mockImplementation(query => ({
+      matches: false,
+      media: query,
+      onchange: null,
+      addEventListener: vi.fn(),
+      removeEventListener: vi.fn(),
+      addListener: vi.fn(), // Deprecated since Chrome 64, Firefox 65, Safari 14; use addEventListener instead. Included for legacy code compatibility.
+      removeListener: vi.fn(), // Deprecated since Chrome 64, Firefox 65, Safari 14; use removeEventListener instead. Included for legacy code compatibility.
+      dispatchEvent: vi.fn()
+    }))
   });
 }
 
@@ -58,4 +67,4 @@ afterEach(() => {
   vi.restoreAllMocks();
   vi.clearAllMocks();
   document.body.innerHTML = '';
-});
\ No newline at end of file
+});