<!DOCTYPE html>
<html>
<!--
 | This test ensures that an element with a non-positioned stacking context
 | above its positioned containing block will have its offset from the
 | containing block calculated correctly. The results should display the blue
 | block directly under the green block.
 |   https://www.w3.org/TR/CSS21/visudet.html#containing-block-details
 -->
<head>
  <style>
    body {
      font-family: Roboto;
      font-size: 16px;
    }
    .non-positioned-stacking-context {
      position: static;

      opacity: .9;

      width: 300px;
      height: 50px;
      margin-left: 40px;
    }
    .absolute-container {
      position: absolute;

      width: 300px;
      height: 50px;

      background-color: rgb(15, 157, 88);
    }
    .positioned-element {
      position: absolute;

      z-index: 1;

      width: 300px;
      height: 20px;
      top: 60px;

      background-color: rgb(66, 133, 244);
    }
  </style>
</head>
<body>
  <div class="non-positioned-stacking-context">
    <div class="absolute-container">
      <div class="positioned-element"></div>
    </div>
  </div>
</body>
</html>