<!DOCTYPE html>
<style>
  #container {
    height: 300px;
    width: 300px;
    background-color: green;
  }

  #parent {
    position: absolute;
    left: 408px;
    width: 300px;
    height: 300px;
    background-color: green;
  }
</style>
<body>
<div id="container">
  <div id="parent">
  </div>
</div>
</body>