@function lightness($h, $s, $l, $lightness) {
	@return hsl(var(#{$h}), var(#{$s}), calc(var(#{$l}) + #{$lightness}));
}

@function saturation($h, $s, $l, $saturation) {
	@return hsl(var(#{$h}), calc(var(#{$s}) + #{$saturation}), var(#{$l}));
}