Stylesheet Limits in Internet Explorer 9 and below (cf. http://blogs.msdn.com/b/ieinternals/archive/2011/05/14/internet-explorer-stylesheet-rule-selector-import-sheet-limit-maximum.aspx)

ie9-selector-limit.js

$.each(document.styleSheets, function(index) {
	var id = this.href || '[inline]',
		rules = this.cssRules ? this.cssRules.length : 0,
		selectors = 0;

	$.each(this.cssRules, function() {
		if (this.selectorText) {
			try {
				selectors += this.selectorText.split(',').length;
			} catch (err) {
				console.log(err);
			}
		}
	});

	var msg = 'Stylesheet ' + index + ': [id=' + id + ', rules=' + rules + ', selector=' + selectors + ']';
	console.log(msg);
	if(selectors >= 4095) {
		alert(msg);
	}
});