<!DOCTYPE html>
<html>
<head>
  <style>
    div {
      background-color: white;
      width: 12px;
      height: 60px;
    }
    body {
      background-color: black;
      margin:  0px;
      padding: 0px;
      border:  0px;
    }
  </style>
</head>
<body>
  <div></div>
</body>
</html>