title: Why does chrome always add a div on top of the body of html files?
body: <p>I am new to Web development and after inspecting a decent amount of websites, I have discovered that chrome always adds this <code>div</code> on top of the <code>body</code> :</p>
  
  <pre><code>&lt;div id="screen-shader" style="
          transition: opacity 0.1s ease 0s; 
          z-index: 2147483647;
          margin: 0; 
          border-radius: 0; 
          padding: 0; 
          background: #111111; 
          pointer-events: none; 
          position: fixed; 
          top: -10%; 
          right: -10%; 
          width: 120%; 
          height: 120%; 
          opacity: 0.6000;
          mix-blend-mode: multiply; 
          display: none;
      "&gt;&lt;/div&gt;
  </code></pre>
  
  <p>So I was just wondering what does it actually do ?</p>