First swing.

src/router/pages/NotFoundPage.tsx

@@ -0,0 +1,30 @@
+import { Link } from 'react-router';
+import { AlertCircle, Home } from 'lucide-react';
+import { Card, CardHeader, CardTitle, CardDescription, CardContent } from '../../components/ui/card';
+import { Button } from '../../components/ui/button';
+
+export function NotFoundPage() {
+  return (
+    <div className="flex items-center justify-center min-h-[600px]">
+      <Card className="w-full max-w-md">
+        <CardHeader className="text-center">
+          <div className="flex justify-center mb-4">
+            <AlertCircle className="h-16 w-16 text-destructive" />
+          </div>
+          <CardTitle className="text-2xl">Page Not Found</CardTitle>
+          <CardDescription>
+            The page you're looking for doesn't exist or has been moved.
+          </CardDescription>
+        </CardHeader>
+        <CardContent className="flex justify-center">
+          <Link to="/">
+            <Button>
+              <Home className="mr-2 h-4 w-4" />
+              Go to Home
+            </Button>
+          </Link>
+        </CardContent>
+      </Card>
+    </div>
+  );
+}