/// Rhythm function to calculate a percentage of the (base-)font-size
//// @group Rhythm
/// @param {value} $lines [1] - value
/// @param {value} $font-size [$base-font-size] - font-size
/// @param {value} $offset [0] - value
@function rhythm($lines: 1, $font-size: $base-font-size, $offset: 0) {
  $rhythm: convert-length($lines * $base-line-height - $offset, $rhythm-unit, $font-size);
  @if unit($rhythm) == px {
    $rhythm: floor($rhythm);
  }
  @return $rhythm;
}