An advanced rem fallback in Sass

rem.scss

$main-font-size: 16px;

@mixin x-rem($property, $values) {

	// Empty list for all values in px
	$px-values: ();
	$rem-values: ();

	// Iterate over entries
	@each $value in $values {

		// If the value is zero, return 0
		@if $value == 0 {
			$px-values: append($px-values, $value);
			$rem-values: append($rem-values, $value);

		// If the value is not zero, convert it from px to rem
		} @else {
			$px-values: append($px-values, ($value * $main-font-size) );
			$rem-values: append($rem-values, #{$value}rem);
		}
	}

	// Return the property and its list of converted values
	#{$property}: #{$px-values};
	#{$property}: #{$rem-values};
}