I want to only apply a bootstrap margin on xs and sm devices
I've inserted mt-4 mt-sm-4 on an element so that it only targets extra small and small devices.
This works however I'm finding that the margin is also being applied on larger destkop devices so I had to zero out the margins by including mt-md-0 and mt-lg-0. Is there a reason why I have to zero out the margins as I thought that if I targetted the xs and sm devices then it would only apply there. I'm just not sure how bootstrap works, ie. if I apply a class to a smaller device, does that mean it will apply to that device plus all larger devices?