text: <!DOCTYPE html>
  <html   lang="" >
  <head>
  <meta charset="utf-8"/>
  <title>lang="" vs HTTP</title>
  <link rel='author' title='Richard Ishida' href='mailto:ishida@w3.org'>
  <link rel='help' href='https://html.spec.whatwg.org/multipage/#the-lang-and-xml:lang-attributes'>
  <script src="/resources/testharness.js"></script>
  <script src="/resources/testharnessreport.js"></script>
  <meta name='flags' content='http dom'>
  <style type='text/css'>
      #colonlangcontroltest { color: red; font-weight: bold; width: 400px; }
      #colonlangcontroltest:lang(xx) { display:none; }
  .test div { width: 50px; }
  #box:lang(ko) { width: 100px; }
  </style>
  </head>
  <body>
  
  
  
  <div class="test"><div id="box">&#xA0;</div></div>
  <p lang='xx' id='colonlangcontroltest'>This test failed because it relies on :lang for results, but :lang is not supported by this browser.</p>
  
  
  <!--Notes:
  
  This test uses :lang to detect whether the language has been set. If :lang is not supported, a message will appear and the test will fail.
  
  -->
  <script>
  test(function() {
  assert_equals(document.getElementById('colonlangcontroltest').offsetWidth, 0)
  assert_equals(document.getElementById('box').offsetWidth, 50);
  }, "If the HTTP header contains a language declaration but the html element uses an empty lang value, the UA will not recognize the language declared in the HTTP header.");
  </script>
  
  <div id='log'></div>
  
  </body>
  </html>
  