Transparency Mixin =opacity(!opacity) opacity: !opacity /* for All Good browsers */ -moz-opacity: !opacity /* for Mozilla & Netscape */ -khtml-opacity: !opacity /* for Safari & Webkit */ -ms-filter: "progid:DXImageTransform.Microsoft.Alpha(Opacity=" + round(!opacity*100) + ")" /* for IE 8*/ filter: "alpha(opacity=" + round(!opacity*100) + ")" /* for IE 5-7 */