<!DOCTYPE html>
<!--
 | The percentage is calculated with respect to the width of the generated box's
 | containing block, even for "padding-top" and "padding-bottom".
 |   https://www.w3.org/TR/CSS21/box.html#padding-properties
 -->
<html>
<head>
  <style>
    .absolute {
      position: absolute;
    }
    .level-1 {
      background-color: #00b0ff;
      height: 100px;
      width: 200px;
    }
    .level-2 {
      background-color: #1de9b6;
      height: 200px;
      width: 100px;
    }
    .level-3 {
      background-color: #00bfa5;
      display: inline-block;
      padding: 50%;
    }
    .level-3.absolute {
      background-color: #0091ea;
      left: 200px;
    }
  </style>
</head>
<body>
  <div class="level-1 absolute">
    <div class="level-2">
      <div class="level-3 absolute"></div>
      <div class="level-3"></div>
    </div>
  </div>
</body>
</html>