title: Target elements with multiple classes, within one rule
body: <p>I have some HTML that would have elements with multiple classes, and I need to assign them within one rule, so that the same classes could be different within different containers. Say I have this in my CSS:</p>
  
  <pre><code>.border-blue {
      border: 1px solid blue;
  }
  .background {
      background: url(bg.gif);
  }
  </code></pre>
  
  <p>Then I have this in my HTML:</p>
  
  <pre><code>&lt;div class='border-blue background'&gt;Lorum Crap No-one Cares About Ipsum&lt;/div&gt;
  </code></pre>
  
  <p>Can I target these within a single rule? Like this, for example, which I know doesn't work:</p>
  
  <pre><code>.border-blue, .background {
      border: 1px solid blue;
      background: url(bg.gif);
  }
  </code></pre>