void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
        useMaterial3: true,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key, required this.title});

  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: CustomScrollView(
        slivers: [
          const SliverAppBar(
            backgroundColor: Colors.red,
            expandedHeight: 300.0,
            pinned: true,
            flexibleSpace: FlexibleSpaceBar(
              background: FlutterLogo(),
              centerTitle: true,
            ),
          ),
          SliverList(
            delegate: SliverChildBuilderDelegate(
              childCount: 100,
              (context, index) => const SizedBox(
                height: 100,
                child: Center(
                  child: Text('something here'),
                ),
              ),
            ),
          ),
        ],
      ),
    );
  }
}