ps://www.w3.org/TR/css-conditional-3/#at-supports">
	<link rel="match" href="at-supports-001-ref.html">
	<meta name="assert"
	      content="Test passes if namespaces used within @supports are valid only if declared in a valid @namespace rule.">
	<style>
		@namespace x "http://www.w3.org/1999/xlink";
		@supports (background: green) {}
		@namespace y "http://www.w3.org/1999/xlink";

		div {
			height: 20px;
			width: 100px;
		}

		.test1 { background: red; }
		@supports (content: attr(x|href)) {
			.test1 { 