/**
 * Returns multiple unit
 * @param {number (unitless)} $multiple
 * @return {number (rem)}
 */
@function unit($multiple: 1) {
   @return $aui-base-unit * $multiple / $aui-rem-base * 1rem;
}

/**
 * Convert pixels to ems
 * eg. for a relational value of 12px write em(12) when the parent is equal
 * the em-base (defined in $audui-config).
 * If the parent is another value say 24px write em(12, 24)
 * @param {number (px)} $val
 * @param {number} $base
 * @return {number (em)}
 */
@function em($val, $base: $aui-rem-base) {
  $val: strip-units($val);
  $base: strip-units($base);
  @return ($val / $base) * 1em;
}

/**
 * Convert pixels to rems
 * Assumes that the defined em-base is the font-size of <html>
 * @param {number (px)} $val
 * @param {number} $base
 * @return {number (rem)}
 */
@function rem($val) {
  $val: strip-units($val);
  $base: strip-units($aui-rem-base);
  @return ($val / $base) * 1rem;
}

/**
 * Strips the unit from a number.
 * @param {number (with unit)} $value
 * @return {number (unitless)}
 */
@function strip-units($value) {
   @return ($value / ($value * 0 + 1));
}