.logo {
    $logo-width: 200px;
    $logo-height: 53px;
    background-size: $logo-width $logo-height;
    display: inline-block;
    width: $logo-width;
    height: $logo-height;
    @include img-retina($image-path-base + "logo.png", $image-path-base + "logo@2x.png", $logo-width, $logo-height);

    @media screen and (max-width: $screen-sm) {
        width: $logo-width - 40px;
        height: $logo-height - 15px;
    }
}