title: CSS override for mobile devices
body: <p>I have CSS that looks like this:</p>
  
  <pre><code>#FSBDiv-Inner {
      position: fixed;
      top: 20%;
      left: 25%;
      width: 50%;
      z-index: 999;
      display: flex;
      justify-content: center;
      background-color: white;    
  }
  </code></pre>
  
  <p>for mobile devices I need to to do this:</p>
  
  <pre><code>#FSBDiv-Inner {
      position: fixed;
      top: 20%;
      width: 100%; 
      z-index: 999;
      display: flex;
      justify-content: center;
      background-color: white;    
  }
  </code></pre>
  
  <p>What do I need to do to the css entry to change values depending on screen resolution?</p>