css/mediaqueries/media-queries-001.xht

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
 <head>
  <title>Basic media queries test</title>
  <link rel="author" title="Ian Hickson" href="mailto:ian@hixie.ch"/>
  <link rel="alternate" href="http://www.hixie.ch/tests/adhoc/css/media/queries/001.html"/>
  <link rel="help" href="https://www.w3.org/TR/css3-mediaqueries/#media0"/>
    <style type="text/css"><![CDATA[
   @media only screen {
     .a, .b { color: green; }
   }
   @media not only screen {
     .b { color: red; }
   }
  ]]></style>
 </head>
 <body>
  <p class="a"> This line should be green. </p>
  <p class="b"> This line should be green. </p>
 </body>
</html>