<!DOCTYPE HTML> <html> <head> <style> body { color: green } </style> <link rel="stylesheet" href="data:text/css,@media no-such-medium { body { color: red } }" type="text/css"> <link rel="stylesheet" href="data:text/css,@media no-such-medium { body { color: red } }" type="text/css"> <script> // Force cloning of the second linked sheet document.styleSheets[2].cssRules[0]; </script> </head> <body>test</body> </html>