Mixin for REM font-size

font-size.less

/** Font Size is in REMs,margins are mutiples of the base value
    Line height is automatically set based upon the font size */
.font-size(@sizeValue, @margin-bottom: 0, @margin-top: 0)
{
    @base: 2.2;
	@remValue: @sizeValue;
	@pxValue: (@sizeValue * 10);
	@lineHeightRem: ceil(@sizeValue / @base)*@base;
	@lineHeightPx:   (@lineHeightRem * 10);
	@marginTopRem: (@margin-top * @base);
	@marginTopPx: (@marginTopRem * 10);
	@marginBottomRem: (@margin-bottom * @base);
	@marginBottomPx: (@marginBottomRem * 10);
	font-size: ~"@{pxValue}px";
	font-size: ~"@{remValue}rem";
	line-height: ~"@{lineHeightPx}px";
	line-height: ~"@{lineHeightRem}rem";
	margin-top: ~"@{marginTopPx}px";
	margin-top: ~"@{marginTopRem}rem";
	margin-bottom: ~"@{marginBottomPx}px";
	margin-bottom: ~"@{marginBottomRem}rem";
}