Flutter webでfooterを実装する方法

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(),
    );
  }
}

class MyHomePage extends StatelessWidget {
  const MyHomePage({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('CustomScrollView'),
      ),
      body: CustomScrollView( // ⇦ ここ
        slivers: [
          SliverToBoxAdapter(
            child: Column(
              children: [
                Container(
                  height: 200,
                  color: Colors.blue,
                ),
                Container(height: 100, color: Colors.cyan)
              ],
            ),
          ),
          SliverFillRemaining( // ⇦ ここ
            hasScrollBody: false, // ⇦ ここ
            child: Column(
              children: [
                const Spacer(), // ⇦ ここ
                Container(
                  width: double.infinity,
                  child: const Center(child: Text("This is Footer")),
                  decoration: BoxDecoration(
                    border: Border.all(color: Colors.black26, width: 1),
                  ),
                )
              ],
            ),
          )
        ],
      ),
    );
  }
}