title: How to style parent element if child element is empty?
body: <p>Is there a way to style a parent element if the child element is empty? For example:</p>
  
  <p>Here, the <code>&lt;li&gt;</code> element <em>is</em> empty so I'd like the <code>ul</code> element to be styled with <code>padding: 20px</code>:</p>
  
  <pre><code>&lt;ul class="list"&gt;
      &lt;li&gt;&lt;/li&gt;
  &lt;/ul&gt;
  </code></pre>