title: Responsive show/hide classes in new Bootstrap 4
body: <p>I'm struggling to understand how to implement the new classes that show and hide content relevant to screen size in Bootstrap 4</p>
  
  <p>This doesn't seem to be working...</p>
  
  <pre><code>&lt;div class="d-sm-block"&gt;
   ITEMS FOR SMALL/MOBILE DEVICES
  &lt;/div&gt;
  &lt;div class="d-md-block"&gt;
   ITEMS FOR  MEDIUM/LARGE DEVICES
  &lt;/div&gt;
  </code></pre>