h: 4em;
  }
  </style>

 </head>

 <body>

  <p>Below there should be a green square. In the middle of such green square, a black horizontal stripe should be traversing it and protruding out of it toward the right. There should be no red in this page.</p>

  <div>
    <div>XXXXXXXX</div>
  </div>

 </body>
</html>