title: CSS Hide class/ID depending on other class being active
body: <p>I have a menu bar that shows in 1 state when page loads, as soon as you scroll down the menu bar shrinks and is given a class of <code>.roll_activated</code> which controls height and sizing.</p>
  
  <p>I have a div that I would only like to show when the <code>.roll_activated</code> is not <code>active</code></p>
  
  <p>I'm missing something with my code here:</p>
  
  <pre><code>.roll_activated:HLinfobox{display:none !important;}
  </code></pre>
  
  <p>The div I want to hide has a class of <code>HLinfobox</code></p>