<!DOCTYPE html>
 <head>
  <title>CSS Reference File</title>
  <style type="text/css">
     .container {
          position: absolute;
          height: 200px;
          width: 100px;
          background-color:green;
          margin-top: 150px;
      }
  </style>

 </head>
 <body>
  <p>You should see only 1 green area.</p>
  <div class="container">
  </div>
</body>
</html>