Resize Gulp Smiths Sprite

gulp.spritesmiths-resized.scss

@mixin sprite-resized($sprite-image, $ratio) {
    background-position: (nth($sprite-image, 3) * $ratio) (nth($sprite-image, 4) * $ratio);
    background-size: (nth($sprite-image, 7) * $ratio) (nth($sprite-image, 8) * $ratio);
    width: nth($sprite-image, 5) * $ratio;
    height: nth($sprite-image, 6) * $ratio;
}

// Notice: background-image not specified here. Extend from common sprite class or add manually.
.logo {
    @include sprite-resized($icon-logo, 0.5);
}