@mixin rem($property, $values) {
  $px : ();
  $rem: ();

  @each $value in $values {
    @if $value == 0 or type-of($value) != "number" {
      $px : append($px , $value);
      $rem: append($rem, $value);
    } @else {
      $unit: unit($value);
      $val: parseInt($value);

      @if $unit == "px" {
        $px : append($px, $value);
        $rem: append($rem, ($val / 16 + rem));
      }

      @if $unit == "rem" {
        $px : append($px, ($val * 16 + px));
        $rem: append($rem, $value);
      }
    }
  }

  @if $px == $rem {
    #{$property}: $px;
  } @else {
    #{$property}: $px;
    #{$property}: $rem;
  }
}