css/css-values/attr-px-invalid-cast.html

<!DOCTYPE html>
<html>
<head>
	<meta charset="utf-8">
	<title>
		CSS Values and Units Test:
		Attributes references (pixels)
	</title>
	<meta name="assert" content="
		When the value of the referenced attribute is not a pixel value, the fallback value is used instead.
	" />

	<link
		rel="author"
		title="François REMY"
		href="mailto:fremycompany.developer@yahoo.fr"
	/ >

	<link rel="help" href="http://www.w3.org/TR/css3-values/#attr-notation"/>

	<link
		rel="match"
		href="reference/200-200-green.html"
	/>

	<style type="text/css">

			html, body { margin: 0px; padding: 0px; }

			html { background: white; overflow: hidden; }
			#outer { position: relative; background: green; }

			#outer { width: attr(data-test px, 200); height: 200px; }

	</style>

</head>
<body>

	<div id="outer" data-test="300px"></div>

</body>
</html>