diff --git a/app/admin/test/page.tsx b/app/admin/test/page.tsx
new file mode 100644
index 0000000..fc7aed4
--- /dev/null
+++ b/app/admin/test/page.tsx
@@ -0,0 +1,19 @@
+'use client';
+import { useState } from 'react';
+
+export default function Test() {
+  console.log('[TEST] mounted');
+  const [n, setN] = useState(0);
+  return (
+    <div style={{ padding: 40, fontSize: 24 }}>
+      <h1>Hydration test</h1>
+      <p>Count: {n}</p>
+      <button
+        onClick={() => { console.log('[TEST] click'); setN(n + 1); }}
+        style={{ padding: '10px 20px', background: '#007', color: '#fff', cursor: 'pointer' }}
+      >
+        Click me
+      </button>
+    </div>
+  );
+}