Quantity Queries in Sass

quantity-query.scss

@mixin quantity-query($selector, $type, $amount, $max: null) {
    @if $type == at-least {
        #{$selector}:nth-last-child(n+#{$amount}),
        #{$selector}:nth-last-child(n+#{$amount}) ~ #{$selector} { @content; }
    } @else if $type == at-most {
        #{$selector}:nth-last-child(-n+#{$amount}):first-child,
        #{$selector}:nth-last-child(-n+#{$amount}):first-child ~ #{$selector} { @content; }
    } @else if $type == between {
        @if type-of($max) != "number" {
            @error "Max value must be a number for quantity-query.";
        }

        #{$selector}:nth-last-child(n+#{$amount}):nth-last-child(-n+#{$max}):first-child,
        #{$selector}:nth-last-child(-n+#{$amount}):nth-last-child(-n+#{$max}):first-child ~ #{$selector} { @content; }
    } @else {
        @error "Invalid type `#{$type}` for quantity-query. Allowed types - at-least, at-most, between.";
    }
}

Usage:

@include quantity-query("ul > li", at-least, 5) { color: blue; };

@include quantity-query(div, at-most, 3) { color: green; };

@include quantity-query(section p, between, 3, 5) { color: red; };