title: Sticky position not working on div element
body: <p>I'm trying to make a div sticky positioned relative to the viewport so it sticks to the top when it gets scrolled out of view but it isn't working.</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-css lang-css prettyprint-override"><code>#navigation {
    display: flex;
    background-color: #AA1111;
    width: 100%;
    height: 50px;
    z-index: 10;
    position: sticky;
    position: -webkit-sticky;
    top: 0;
  }
  
  header {
    height: auto;
    display: flex;
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;body&gt;
    &lt;div class="page"&gt;
      &lt;header&gt;
        &lt;div id="navigation"&gt;
        &lt;/div&gt;
      &lt;/header&gt;
    &lt;/div&gt;
  &lt;/body&gt;</code></pre>
  </div>
  </div>
  </p>