Card(
color: Colors.grey[900],
shape: RoundedRectangleBorder(
side: BorderSide(color: Colors.white70, width: 1),
borderRadius: BorderRadius.circular(10),
),
margin: EdgeInsets.all(20.0),
child: Container(
child: Column(
children: <Widget>[
ListTile(
title: Text(
'example',
style: TextStyle(fontSize: 18, color: Colors.white),
),
),
],
),
),
),