SASS mixin for REM based font sizing with a pixel value fallback for IE8

gistfile1.scss

@mixin font-size($size, $modifier:1.6) {
	/* For optimal use, adjust the default modifier value until it gives you the 
	same pixel value as the computed pixel value you get from using REMs.
	If your root font-size is 100%, this will be 1.6  */
	
	// IE 8 fallback in pixels
	$pixel-size: ($size * 10) * $modifier;
	font-size: #{$pixel-size}px;

	// fontsize in REM
	font-size: #{$size}rem;
}