function render(BuildContext context) {
    return Container(
        // mb10
        margin: EdgeInsets.only(bottom: 10),
        // grd b/w top t b
        decoration: BoxDecoration(
            gradient: LinearGradient(
                colors: [Colors.black, Colors.white],
                begin: Alignment.topCenter,
                end: Alignment.bottomCenter,
            ),
        ),
        child: Text('Hello World'),
    );
}