gistfile1.html

<polymer-element name="style-test" attributes="color" noscript>
	<template>
		<style>
		.styled { color: red; }
		.styled:after {
			content: "Should be green!";
			color: {{color}};
		}
		</style>
		<p class="styled">The following text is red, but:</p>
	</template>
</polymer-element>

<style-test color="green"></style-test>