cardWidget.dart

...
  
_buildTitle() => Row(
        mainAxisAlignment: MainAxisAlignment.start,
        children: <Widget>[
          Row(
            mainAxisAlignment: MainAxisAlignment.start,
            children: <Widget>[
              Text(
                'D E B I T',
                style: TextStyle(
                    color: Colors.white,
                    fontSize: 11,
                    fontWeight: FontWeight.w200),
              ),
            ],
          ),
          customYMargin(35),
          Row(
            mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[
              Text(
                '$amount',
                style: TextStyle(
                    color: Colors.white,
                    fontSize: 27,
                    fontFamily: 'Roboto',
                    fontWeight: FontWeight.w400),
              ),
            ],
          ),
          customYMargin(40),
        ],
      );

...