title: Overflow: hidden not working with full viewport sections
body: <p>I have a set up with several sections that have a full-screen width and height. Whether I position them absolute or relative the overflow still doesn't work. </p>
  
  <p><a href="https://jsfiddle.net/vdghk7u6/" rel="nofollow">DEMO</a></p>
  
  <pre><code>section {
    height: 100vh;
    width: 100vw;
    overflow: hidden;
  }
  
  #a {
    background: linear-gradient(1deg, #9f00b8, #2a032d);
    position: absolute;
  }
  
  #b {
    background: linear-gradient(1deg, #25cc00, #2a032d);
    left: 100vw;
    position: relative;
  }
  </code></pre>