<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
   "http://www.w3.org/TR/html4/loose.dtd">

<html lang="en">
<head>
  <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
  <title>Overflow Test</title>
  <style type="text/css" media="screen">
    .container {
      display: inline-block;
      margin: 20px;
      width: 100px;
      height: 100px;
      padding: 10px;
      border: 1px solid black;
      overflow: hidden;
    }
    
    .box {
      width: 100px;
      height: 300px;
      background-color: gray;
      -webkit-transform: translateZ(0);
    }
  </style>
</head>
<body>
<p>Gray box should be clipped by black border in each case.</p>
<div class="container">
  <div class="box">
  </div>
</div>

<div class="container" style="position: relative">
  <div class="box">
  </div>
</div>

<div class="container" style="position: relative; z-index: 0">
  <div class="box">
  </div>
</div>

</body>
</html>