Yeah, good point. I'm not sure how to get around it. I thought about changing the `border-color`, but that gets over-ridden by the button-group `border-color`. If we don't want things to shift, then the only options appear to be `border-color`. I can try to change up the styles a bit to make it work. What do you think about using a darker `border-color` for the active state when box-shadow is not supported?