define(function () {
	if (typeof window == "undefined")return{load: function (n, r, load) {
		load()
	}};
	var head = document.getElementsByTagName("head")[0];
	var engine = window.navigator.userAgent.match(/Trident\/([^ ;]*)|AppleWebKit\/([^ ;]*)|Opera\/([^ ;]*)|rv\:([^ ;]*)(.*?)Gecko\/([^ ;]*)|MSIE\s([^ ;]*)/) || 0;
	var useImportLoad = false;
	var useOnload = true;
	if (engine[1] || engine[7])useImportLoad = parseInt(engine[1]) < 6 || parseInt(engine[7]) <= 9; else if (engine[2])useOnload = false; else if (engine[4])useImportLoad = parseInt(engine[4]) < 18;
	var cssAPI = {};
	cssAPI.pluginBuilder = "./css-builder";
	var curStyle;
	var createStyle = function () {
		curStyle = document.createElement("style");
		head.appendChild(curStyle)
	};
	var importLoad = function (url, callback) {
		createStyle();
		var curSheet = curStyle.styleSheet || curStyle.sheet;
		if (curSheet && curSheet.addImport) {
			curSheet.addImport(url);
			curStyle.onload = callback
		} else {
			curStyle.textContent = '@import "' + url + '";';
			var loadInterval = setInterval(function () {
				try {
					curStyle.sheet.cssRules;
					clearInterval(loadInterval);
					callback()
				} catch (e) {
				}
			}, 10)
		}
	};
	var linkLoad = function (url, callback) {
		var link = document.createElement("link");
		link.type = "text/css";
		link.rel = "stylesheet";
		if (useOnload)link.onload = function () {
			link.onload = function () {
			};
			setTimeout(callback, 7)
		}; else var loadInterval = setInterval(function () {
			for (var i = 0; i < document.styleSheets.length; i++) {
				var sheet = document.styleSheets[i];
				if (sheet.href == link.href) {
					clearInterval(loadInterval);
					return callback()
				}
			}
		}, 10);
		link.href = url;
		head.appendChild(link)
	};
	cssAPI.normalize = function (name, normalize) {
		if (name.substr(name.length - 4, 4) == ".css")name = name.substr(0, name.length - 4);
		return normalize(name)
	};
	cssAPI.load = function (cssId, req, load, config) {
		(useImportLoad ? importLoad : linkLoad)(req.toUrl(cssId + ".css"), load)
	};
	return cssAPI
});