<html>
<head>
<title>CSS3 media query test: media query testing orientation feature.</title>
<style type="text/css">
@media screen and (orientation:portrait) {
#a { color: green }
}
@media screen and (orientation:landscape) {
#b { color: green }
}
</style>
</head>
<body>
  <p id="a">This text should be green if the viewport is portrait.</p>
  <p id="b">This text should be green if the viewport is landscape.</p>
  <p>Obviously, at least one should be green, but never both. Square is portrait.</p>
</body>
</html>