chat_room.dart

class ChatRoom extends StatelessWidget   {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: Color(0xFFECE5DD),
      appBar: AppBar(...), // Title text, action buttons on the right
      body: Column(
        children: <Widget>[
          Expanded(
            child: ListView(...), // chat threads
          ),
          Row(...), // input field + send button
        ],
      
      // ...