blog-static/themes/vanilla/assets/scss/margin.scss

@import "variables.scss";
@import "mixins.scss";

$margin-width: 30rem;
$margin-offset: 1.5rem;

@mixin below-two-margins {
    @media screen and
        (max-width: $container-width +
            2 * ($margin-width + 2 * $margin-offset)) {
        @content;
    }
}

@mixin below-one-margin {
    @media screen and
        (max-width: $container-width +
            ($margin-width + 3 * $margin-offset)) {
        @content;
    }
}

@mixin margin-content {
    display: block;
    position: absolute;
    width: $margin-width;
    box-sizing: border-box;
}

@mixin margin-content-left {
    left: 0;
    margin-left: -($margin-width + $margin-offset);

    @include below-two-margins {
        display: none;
    }
}

@mixin margin-content-right {
    right: 0;
    margin-right: -($margin-width + $margin-offset);

    @include below-one-margin {
        display: none;
    }
}