Media Queries werden entfernt

<!DOCTYPE html>
<html>
<head>
   <meta http-equiv="content-type" content="text/html; charset=UTF-8">
   <style type="text/css">
       @font-face {
           font-family: "OpenSans_Light";
           src: url("https://fonts.googleapis.com/css?family=Open Sans");
       }
       h1, h2, h3, h4 {
           font-family: "OpenSans_Light", Arial, sans-serif;
           font-weight: 300;
           color: red;
       }
       @media only screen and (max-width: 600px) {
          p { background-color: yellow; font-size: 16px; } 
       }
   </style>
</head>
<body>
    <h1>Testmail</h1>
    <p>Das ist ein Test</p>
</body>
</html>