title: CSS subclasses, am I doing it right?
body: <pre><code>.popUp
  {
      width: 300px;
      height: 300px;
      position: fixed;
      top: 0px;
      left: 0px;
      background-color: white;
  }
  .question .popUp
  {
      width: 300px;
      height: 20px;
      border: 1px solid black;
      background-color: black;
  }
  </code></pre>
  
  <p>As you can see I'm trying to make the question class a subclass of the popUp class. From what I googled this should work, but it doesn't. If I do this instead:</p>
  
  <pre><code>.question
  {
      width: 300px;
      height: 20px;
      border: 1px solid black;
      background-color: black;
  }
  </code></pre>
  
  <p>It works, but that misses the point.</p>