app_notificaciones_ador/lib/widgets/background_widget.dart

import 'package:flutter/material.dart';

class BackgroundWidget extends StatelessWidget {
  final Widget child;

  const BackgroundWidget({required this.child, Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Stack(
      children: [
        Positioned.fill(
          child: Image.asset(
            'assets/logo-fondo-verde.png',
            fit: BoxFit.cover,
          ),
        ),
        child,
      ],
    );
  }
}