title: overflow-y: scroll not working, showing style but cannot be scrolled?
body: <p>my code is simple like this: </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>.list {
      margin: auto;
      height: 285px;
      width: 300px;
      overflow-y: scroll;
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;div class="list"&gt;
    &lt;ul&gt;
      &lt;li&gt;hello world&lt;/li&gt;
      &lt;li&gt;hello jupiter&lt;/li&gt;
      &lt;li&gt;hello mars&lt;/li&gt;
    &lt;/ul&gt;
  &lt;/div&gt;</code></pre>
  </div>
  </div>
  </p>
  
  <p>it shows style of a scroll on the side but lacking that scroll you use to move up and down?</p>