title: Select class that does not begin with string
body: <p>I want to select a child element that does not contain a class that begins with <code>z-depth-</code>:</p>
  
  <pre><code>&lt;div class="well"&gt;
      &lt;div class="well"&gt;&lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>So that if the inner .well also contained a class like <code>z-depth-1</code> it would not be selected.</p>
  
  <p>This isn't working because the inner .well is always selected:</p>
  
  <pre><code>.well .well:not([class^="z-depth-"])
  </code></pre>
  
  <p>Is that even possible?</p>