<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> <html> <head> <title>CSS Test: An @supports rule with valid syntax but a failing condition must not apply rules inside it</title> <link rel="author" title="Cameron McCormack" href="mailto:cam@mcc.id.au"> <link rel="help" href="http://www.w3.org/TR/css3-conditional/#at-supports"> <meta name="flags" content=""> <meta name="assert" content="An @supports condition that is a declaration with a supported property name with an unsupported value must fail."> <link rel="match" href="support/pass.htm"> <style type="text/css"> html { background-color: green } @supports (unknown: green) { html { background-color: red } } </style> </head> <body> </body> </html>