update

app/not-found.tsx

@@ -0,0 +1,22 @@
+import Link from "next/link";
+
+export default function NotFound() {
+  return (
+    <div className="flex items-center justify-center h-screen bg-gray-100 dark:bg-gray-800">
+      <div className="text-center p-10 bg-white dark:bg-gray-700 rounded shadow-md">
+        <h1 className="text-6xl font-bold text-gray-800 dark:text-white">
+          404
+        </h1>
+        <p className="mt-4 text-xl text-gray-600 dark:text-gray-300">
+          Oops! The page you're looking for doesn't exist.
+        </p>
+        <Link
+          href="/"
+          className="mt-6 inline-block text-blue-500 hover:underline"
+        >
+          Go Back Home
+        </Link>
+      </div>
+    </div>
+  );
+}