Hi
I'd avoid using negative margins if at all possible
I'd consider targetting something like this rather than negative margins
.formResponsive .formHorizontal .rsform-block-months-at-current-address .formControlLabel,
.formResponsive .formHorizontal .rsform-block-years-at-current-address .formControlLabel
{width: 0%;}
.formResponsive .formHorizontal .rsform-block-months-at-current-address .formControls,
.formResponsive .formHorizontal .rsform-block-years-at-current-address .formControls
{margin-left: 0%;}
.formResponsive .formRow:nth-child(3n) .formSpan6 {width:25%;}
body .rsform-block-months-at-current-address .rsform-input-box{width:25%;}