css/css-conditional/css-supports-002.xht

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
 <head>
  <title>CSS Test: An @supports rule with invalid syntax 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="invalid" />
  <meta name="assert" content="Property declarations in an @supports rule condition must be surrounded by parentheses."/>
  <link rel="match" href="support/pass.xht" />
  <style type="text/css"><![CDATA[
    html { background-color: green }
    @supports color: green {
      html { background-color: red }
    }
  ]]></style>
 </head>
 <body>
 </body>
</html>