Created by: turchenkoalex
visible-* classes now can be mixable with each other and hidden-* too (Issue #8883 (closed))
For example class="visible-xs visible-sm" will be visible at extra small and small screens, class="hidden-xs hidden-lg" hidden for extra small and large screen but visible for small and middle
<div class="visible-xs visible-md">Visible on medium and extra small only</div>
<div class="hidden-xs hidden-md">Visible on small and large only</div>