title: :last-of-type doesn't work
body: <p><img src="https://i.stack.imgur.com/8D0Gd.gif" alt="Example GIF"></p>
  
  <p>I have a HTML document with the abbreviated HTML content:</p>
  
  <pre><code>&lt;div class="list"&gt;
      &lt;form name="signupForm"&gt;
        &lt;label class="item item-input"&gt;
          &lt;input&gt;
        &lt;/label&gt;
        &lt;label class="item item-input"&gt;
          &lt;input&gt;
        &lt;/label&gt;
        &lt;label class="item item-input"&gt;
          &lt;input&gt;
        &lt;/label&gt;
        &lt;label class="item item-input"&gt;
          &lt;input&gt;
        &lt;/label&gt;
        &lt;label class="item item-button"&gt;
          &lt;input class="button button-block button-positive"&gt;
        &lt;/label&gt;
        &lt;label class="item item-button"&gt;
          &lt;input class="button button-block button-signup"&gt;
        &lt;/label&gt;
      &lt;/form&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>My expected behavior is that the CSS selector <code>.item.item-input:last-of-type</code> will grab the 4th <code>label</code> element and the last <code>.item.item-input</code> element of the <code>form</code> parent.</p>
  
  <p>What am I doing wrong?</p>