title: Position fixed not working within overflow hidden parent
body: <p>I have a div that is absolute and have fixed <code>width</code> and <code>height</code>, I have added overflow auto for scroll bar. It has 3 child in this case and one of them is <code>position: fixed</code>, but when I scroll fixed element is also scrolls, I am not sure what I am doing wrong. </p>
  
  <pre><code>&lt;div class="parent"&gt;
  
  &lt;div class="child-1"&gt;
      &lt;h1&gt;Some Text Some TextSome TextSome TextSome TextSome TextSome TextSome TextSome TextSome Text&lt;/h1&gt;
  &lt;/div&gt;
  
  &lt;div class="child-2"&gt;
      &lt;h1&gt;Some Text Some TextSome TextSome TextSome TextSome TextSome TextSome TextSome TextSome Text&lt;/h1&gt;
  &lt;/div&gt;
  
  &lt;div class="child-3"&gt;
      &lt;h1&gt;I am fixed.&lt;/h1&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p></p>
  
  <p>here is css </p>
  
  <pre><code>.parent {
  position: absolute;
  width: 320px;
  right: 0;
  top: 0;
   height: 250px;
   overflow: auto;
  bottom: 0;
  background: yellow;
  z-index: 1000000;
  }
  .parent .child-3 {
      position: fixed;
      right: 0;
      top: 5px;
      color: red;
  }
  </code></pre>