title: How do I center a rectangular div inside another rectangular div
body: <p>I'm trying to make a rectangular div that's 95% the width of the viewport and 20% high. But I want another rectangular div inside of that, that is vertically and horizontally centered with a slight2px margin.</p>
  
  <pre><code>.Outer {
      border: 1px solid #ccc;
      max-width: 95vw;
      max-height: 20vh;
      width: 95vw;
      height: 20vh;
      margin: auto;
      display: block;
      }
  .Inner {
      border: 1px solid hotpink;
      width: 95%;
      height: 95%;
      margin: auto;
      }
  </code></pre>