@mixin x-box-sizing ($type: border-box) {
	-webkit-box-sizing: $type; // Safari <= 5.0, Chrome <= 9.0, iOS Safari 3.2 - 4.3 and Android 2.1 - 3.0
	   -moz-box-sizing: $type; // FF 2.0 - 28.0
	        box-sizing: $type; // IE 8, Opera 9.5+
}