 writing-mode: vertical-rl;
    }

  span#parent
    {
      text-decoration: underline;
    }

  span#child
    {
      color: transparent;
    }
  ]]></style>

 </head>

 <body>

  <p>Test passes if there is <strong>one and only one vertical straight and unbroken line</strong>. Such line should have the same thickness over its entire length.</p>

  <div id="vrl"><span id="parent"><span id="child" lang="ja">方<span lang="en">AB</span>方</span></span></div>

 </body>
</html>