cardWidget.dart

...
  
_buildExpiry() =>
      Row(mainAxisAlignment: MainAxisAlignment.spaceBetween, children: <Widget>[
        Column(crossAxisAlignment: CrossAxisAlignment.end, children: <Widget>[
          Text(
            'EXPIRES',
            style: TextStyle(
                fontSize: 12, color: Colors.white, fontWeight: FontWeight.w200),
          ),
          yMargin5,
          Text(
            '$expiry',
            style: TextStyle(
                color: Colors.white,
                fontFamily: 'OCRAEXT',
                fontSize: 14.4,
                fontWeight: FontWeight.w600),
          ),
        ])
      ]);

...