diff --git a/tests/unit/manifest-platform-matches.test.ts b/tests/unit/manifest-platform-matches.test.ts
new file mode 100644
index 0000000..c2d0672
--- /dev/null
+++ b/tests/unit/manifest-platform-matches.test.ts
@@ -0,0 +1,36 @@
+import { describe, expect, it } from 'vitest';
+import { readFileSync } from 'node:fs';
+import { resolve } from 'node:path';
+
+interface ManifestContentScript {
+  matches?: string[];
+}
+
+interface ManifestWebAccessibleResource {
+  matches?: string[];
+}
+
+interface ExtensionManifest {
+  host_permissions?: string[];
+  content_scripts?: ManifestContentScript[];
+  web_accessible_resources?: ManifestWebAccessibleResource[];
+}
+
+function loadManifest(): ExtensionManifest {
+  return JSON.parse(readFileSync(resolve(process.cwd(), 'manifest.json'), 'utf-8')) as ExtensionManifest;
+}
+
+describe('manifest platform matches', () => {
+  it('injects 123Pan UI only on yun.123pan.cn', () => {
+    const manifest = loadManifest();
+    const contentScriptMatches = manifest.content_scripts?.flatMap((script) => script.matches ?? []) ?? [];
+    const webAccessibleMatches = manifest.web_accessible_resources?.flatMap((resource) => resource.matches ?? []) ?? [];
+
+    expect(manifest.host_permissions).toContain('https://yun.123pan.cn/*');
+    expect(manifest.host_permissions).not.toContain('https://www.123pan.com/*');
+    expect(contentScriptMatches).toContain('https://yun.123pan.cn/*');
+    expect(contentScriptMatches).not.toContain('https://www.123pan.com/*');
+    expect(webAccessibleMatches).toContain('https://yun.123pan.cn/*');
+    expect(webAccessibleMatches).not.toContain('https://www.123pan.com/*');
+  });
+});