title: CSS nth-child: every 3rd element starting from the 4th
body: <p>I'm trying to select every 3rd <code>section</code> tag but starting from the fourth. So the bold elements below would indicate those that I would like to select:</p>
  
  <ol>
  <li>section</li>
  <li>section</li>
  <li>section</li>
  <li><strong>section</strong></li>
  <li>section</li>
  <li>section</li>
  <li><strong>section</strong></li>
  <li>section</li>
  <li>section</li>
  </ol>
  
  <p>I've tried the following code but it doesn't appear to be working</p>
  
  <pre><code>section:nth-child(3n+1)
  </code></pre>