Generated content feature detection

generatedcontent.js

(function() {
	var div = document.createElement("div");
	var style = document.createElement("style");
	div.id = "d";
	style.innerHTML = "#d{position:absolute;left:-999px}#d:before{content:'x';}";
	document.documentElement.appendChild(div);
	document.documentElement.appendChild(style);
	if (div.clientWidth > 0)
		document.documentElement.className += " generated-content";
	document.documentElement.removeChild(div);
	document.documentElement.removeChild(style);
}());