@mixin col-calc($size-name) {
  $i: 1;
  @while $i <= $row-cols {
    $perc: unquote((100 / ($row-cols / $i)) + "%");
    @at-root #{mod(#{$size-name}-#{$i})}{
      width: $perc;
      max-width: $perc;
      flex: 0 0 $perc;
    }
    @at-root #{mod(offset-#{$size-name}-#{$i})}{
      margin-left: $perc;
    }
    @at-root #{mod(push-#{$size-name}-#{$i})}{
      left: $perc;
    }
    @at-root #{mod(pull-#{$size-name}-#{$i})}{
      right: $perc;
    }

    $i: $i + 1;
  }
}