Flutter: neu

main.dart

return Container(
  decoration: BoxDecoration(
      borderRadius: BorderRadius.circular(bevel),
      color: Colors.grey.shade200,
      boxShadow: [
        BoxShadow(
          blurRadius: bevel,
          offset: -blurOffset,
          color: Colors.white,
        ),
        BoxShadow(
          blurRadius: bevel,
          offset: blurOffset,
          color: Colors.grey.shade400
        )
      ]),
  child: child,
);