/**
  * Power function
  */
 
@function pow($number, $exponent) {
  $value: 1;

  @if $exponent > 0 {
    @for $i from 1 through $exponent {
      $value: $value * $number;
    }
  } @else if $exponent < 0 {
    @for $i from 1 through -$exponent {
      $value: $value / $number;
    }
  }

  @return $value;
}

/**
  * Modular typography scale function
  */

@function fontscale($scale){
  
  $headingSize: pow($scale-ratio, $scale);
  
  @return $headingSize#{em}
}