https://stackoverflow.com/questions/45687643/how-to-hide-element-on-small-screens-with-bootstrap-4-beta
<div class="d-none d-md-block">Show on medium, and bigger, screen sizes</div>
<div class="d-md-none">Show on extra small and small screen sizes</div>
<div class="d-none d-md-block d-lg-none">Show on ONLY medium screen sizes</div>
<div class="d-none d-sm-block d-md-none d-xl-block">Show on ONLY small and extra large screen sizes</div>