/***
 * Aspect Ratio
 *
 * Gets padding for correct aspect ratio, and sets height to 0.
 *
 * scss:
 *   @include aspect-ratio($width, $height)
 *
 * @param {Number} $width - comparative width of the ratio. The 'x' in x:y
 * @param {Number} $height - comparative height of the ratio. The 'y' in x:y
 */
@mixin aspect-ratio($width, $height) {
  position: relative;
  padding: ($height / $width) * 100% 0 0 0;
  height: 0;
}