/***
 * Modular Scale Function
 *
 * Determines a size from a base, multiple, and scale factor.
 *
 * scss:
 *   font-size: modularScale(16, 3, 1.5); // 36
 */
@function modularScale ($base: pxToRem(16), $multiple: 1, $factor: 1.5) {
  @return $base * pow($factor, ($multiple - 1));
}