diff --git a/apps/web/src/pages/LoginPage.stories.js b/apps/web/src/pages/LoginPage.stories.js
index c875193..c5630ec 100644
--- a/apps/web/src/pages/LoginPage.stories.js
+++ b/apps/web/src/pages/LoginPage.stories.js
@@ -1,5 +1,22 @@
 import LoginPage from './LoginPage.vue';
+import { expect, userEvent, within } from '@storybook/test';
 
 export default { title: 'Pages/LoginPage', component: LoginPage };
 export const Empty = {};
 export const Loading = { parameters: { docs: { description: { story: 'Submit state is exercised through the live form.' } } } };
+
+export const ErrorFocus = {
+  play: async ({ canvasElement }) => {
+    const originalFetch = window.fetch;
+    window.fetch = async () => new Response(JSON.stringify({ error: { message: 'Invalid credentials.' } }), { status: 401, headers: { 'content-type': 'application/json' } });
+    try {
+      const canvas = within(canvasElement);
+      await userEvent.type(canvas.getByLabelText('Email'), 'seller@example.com');
+      await userEvent.type(canvas.getByLabelText('Password'), 'wrong-password');
+      await userEvent.click(canvas.getByRole('button', { name: 'Sign in' }));
+      await expect(canvas.getByRole('alert')).toHaveFocus();
+    } finally {
+      window.fetch = originalFetch;
+    }
+  },
+};
diff --git a/docs/IMPLEMENTATION-STATUS.md b/docs/IMPLEMENTATION-STATUS.md
index 997f9f6..da5667a 100644
--- a/docs/IMPLEMENTATION-STATUS.md
+++ b/docs/IMPLEMENTATION-STATUS.md
@@ -275,6 +275,7 @@ Remaining roadmap areas are approved external provider credentials/adapters, bro
 - Admin listing status cards now expose a programmatic product heading and status announcement for each listing.
 - Saved-view rows now expose an accessible view name, and the image-limit setting includes range guidance tied to its input.
 - Login errors now move focus to the announced error message so failed authentication is immediately available to keyboard and assistive-technology users.
+- Login error focus behavior now has Storybook interaction coverage using a deterministic failed-authentication response.
 
 ## Local Commands