save before flutter upgrade

lib/pages/page_not_found.dart

@@ -0,0 +1,19 @@
+import 'package:flutter/material.dart';
+import 'package:google_fonts/google_fonts.dart';
+
+class PageNotFoundPage extends StatelessWidget {
+  const PageNotFoundPage({Key? key}) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      body: Center(
+        child: Text(
+          '404 - Page not found',
+          style: GoogleFonts.montserratAlternates(
+              fontSize: 20, fontWeight: FontWeight.bold),
+        ),
+      ),
+    );
+  }
+}