Контейнерная граница осталась
Container(
decoration: BoxDecoration(
border: Border(
left: BorderSide(color: mainColor, width: 3),
),
),
),
loonix
Container(
decoration: BoxDecoration(
border: Border(
left: BorderSide(color: mainColor, width: 3),
),
),
),Container(
child: Text(
'This is a Container',
textScaleFactor: 2,
style: TextStyle(color: Colors.black),
),
decoration: BoxDecoration(
borderRadius: BorderRadius.circular(10),
color: Colors.white,
border: Border(
left: BorderSide(
color: Colors.green,
width: 3,
),
),
),
height: 50,
),