index.dart

import 'package:flutter/material.dart';

final 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: Container(
            child: MyWidget(),
            height: 300,
            )
        ),
      ),
    );
  }
}

class MyWidget extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Column(
      children: [
        Container(
          child: Text("hello"), 
          height: 250, 
          decoration: BoxDecoration(
            border: Border.all(
              color: Colors.green,
              width: 3,
            ),
          ),
        ),
        Expanded(child: Text(
          "world1\nworld2\nworld3\nworld4\nworld5\nworld6\nworld7\nworld8\nworld9",
          overflow: TextOverflow.ellipsis,
maxLines: 6,
        ))
      ]
    );
  }
}