ideefixe

@-moz-document url-prefix() { 
  // css goes here
}

ideefixe

[if {!} browser]
[if {!} browser version]
[if {!} condition browser version]

! - indicates negation of the statement (i.e. NOT) - optional

browser - states which browser the statement targets
  'IE' - Internet Explorer
  'Gecko' - Gecko based browsers (Firefox, Camino etc)
  'Webkit' - Webkit based browsers (Safari, Chrome, Shiira etc)

ideefixe

<!-- iPhone 2G, 3G, 3GS Portrait -->
@media only screen and (device-width: 320px) and (orientation: portrait) and not (-webkit-min-device-pixel-ratio: 2) {
  /* CSS3 Rules for iPhone in Portrait Orientation */
}

<!-- iPhone 2G, 3G, 3GS Landscape -->
@media only screen and (device-width: 480px) and (orientation: landscape) and not (-webkit-min-device-pixel-ratio: 2) {
	/* CSS3 Rules for iPhone in Landscape Orientation */
}

ideefixe

$(window).resize(function() {
  var width = $(window).width();
	if (width < 960) {
		// Do Something
	}
	else {
		//Do Something Else
	}
});