main.dart

import 'package:flutter_web/material.dart';
import 'package:flutter_web_test/flutter_web_test.dart';
import 'package:flutter_web_ui/ui.dart' as ui;

class MyWidget extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Transform.translate(
      offset: Offset(100, 0),
      child: Transform.rotate(
        angle: 1,
        child: BlueBox(),
      ),
    );
  }
}

class BlueBox extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Container(
      width: 50,
      height: 50,
      decoration: BoxDecoration(
        color: Colors.blue,
        border: Border.all(),
      ),
    );
  }
}

test.dart

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Directionality(
      textDirection: TextDirection.ltr,
      child: Container(
        color: Color(0xffeeeeee),
        child: Center(
          child: Container(
            child: MyWidget(),
            color: Color(0xffcccccc),
          ),
        ),
      ),
    );
  }
}

Future<void> main() async {
  await ui.webOnlyInitializePlatform();
  
  runApp(MyApp()); 
}