Debug vertical rhythm with Sass

vr-debug.scss

@mixin vertical-grid($line-height: 24px) {
    position: relative;

    &::before {
        $stripe-color: rgba(blue, 0.2);
        background-image: repeating-linear-gradient(to bottom, $stripe-color, $stripe-color $line-height, transparent $line-height, transparent $line-height * 2);
        bottom: 0;
        content: '';
        left: 0;
        position: absolute;
        right: 0;
        top: 0;
        z-index: 9999;
    }
}