title: Use opacity on only one element in a block in CSS
body: <p>Can you I use <code>opacity</code> only on one property of element?</p>
  <pre><code>nav ul li::after {
      background: grey;
      content: &quot;&quot;;
      height: 3px;
      width: 30%;
      position: absolute;
      left: 0;
      bottom: -10px;
      transition: 0.5s;
      box-shadow: 15px 0px 5px 2.5px #0ff;
      opacity: 0;
  }
  </code></pre>
  <p>Can I use opacity only on the box-shadow?</p>