Created Counter.dart

lib/widgets/counter.dart

@@ -0,0 +1,34 @@
+import 'package:flutter/material.dart';
+
+const Color darkBlue = Color.fromARGB(255, 18, 32, 47);
+
+void main() {
+  runApp(MyApp());
+}
+
+class MyApp extends StatelessWidget {
+  @override
+  Widget build(BuildContext context) {
+    return MaterialApp(
+      theme: ThemeData.dark().copyWith(
+        scaffoldBackgroundColor: darkBlue,
+      ),
+      debugShowCheckedModeBanner: false,
+      home: Scaffold(
+        body: Center(
+          child: MyWidget(),
+        ),
+      ),
+    );
+  }
+}
+
+class MyWidget extends StatelessWidget {
+  @override
+  Widget build(BuildContext context) {
+    return Text(
+      'Hello, World!',
+      style: Theme.of(context).textTheme.headline4,
+    );
+  }
+}