Flutter - Buttons, Containers

// Container with BorderRadius circular and border, and antoher container inside

Container(
  width: 60,
  height: 60,
  decoration: BoxDecoration(
    borderRadius: BorderRadius.circular(30.0),
    border: Border.all(color: Colors.blueAccent, width: 4),
    color: kLightGrey,
  ),
  child: Center(
    child: Container(
      width: 20,
      height: 20,
      decoration: BoxDecoration(
        borderRadius: BorderRadius.circular(30.0),
        color: kGrey,
      ),
    ),
  ),
)