Less mixin for doing font-sizing/line-heights with rems and falling back to px for browsers without rem support.

rem mixin

.font-size(@sizeValue){
	@remValue: @sizeValue / 10;
	@pxValue: (@sizeValue);
	font-size: ~"@{pxValue}px";
	font-size: ~"@{remValue}rem";
}

.line-height(@sizeValue){
	@remValue: @sizeValue / 10;
	@pxValue: (@sizeValue);
	line-height: ~"@{pxValue}px";
	line-height: ~"@{remValue}rem";
}