Custom Element: Repeater Control Field CSS Output

Tested On Bricks 1.6.2

Repeater first item( index0 ) not outputting CSS Value( nth-child(1) ) in backend and frontend. Second item( index1 ) outputting CSS Value( nth-child(2) ) to the first repeater element. I think the repeater index start from 0, CSS pseudo-class start from 1, how to overcome this issue ?