//
// Vertical Rhythm
//
// This is the minimal amount of code needed to create vertical rhythm in our
// CSS. If you are looking for a robust solution, look at the excellent Typey
// library. @see https://github.com/jptaranto/typey

@function normalize-rhythm($value, $relative-to: $base-font-size, $unit: $base-unit) {
    @if unit($value) != px {
      @error "The normalize vertical-rhythm module only supports px inputs. The typey library is better.";
    }
    @if $unit == rem {
      @return ($value / $base-font-size) * 1rem;
    }
    @else if $unit == em {
      @return ($value / $relative-to) * 1em;
    }
    @else { // $unit == px
      @return $value;
    }
  }
  
  @mixin normalize-font-size($value, $relative-to: $base-font-size) {
    @if unit($value) != 'px' {
      @error "normalize-font-size() only supports px inputs. The typey library is better.";
    }
    font-size: normalize-rhythm($value, $relative-to);
  }
  
  @mixin normalize-rhythm($property, $values, $relative-to: $base-font-size) {
    $value-list: $values;
    $sep: space;
    @if type-of($values) == 'list' {
      $sep: list-separator($values);
    }
    @else {
      $value-list: append((), $values);
    }
  
    $normalized-values: ();
    @each $value in $value-list {
      @if unitless($value) and $value != 0 {
        $value: $value * normalize-rhythm($base-line-height, $relative-to);
      }
      $normalized-values: append($normalized-values, $value, $sep);
    }
    #{$property}: $normalized-values;
  }
  
  @mixin normalize-margin($values, $relative-to: $base-font-size) {
    @include normalize-rhythm(margin, $values, $relative-to);
  }
  
  @mixin normalize-line-height($font-size, $min-line-padding: 2px) {
    $lines: ceil($font-size / $base-line-height);
    // If lines are cramped include some extra leading.
    @if ($lines * $base-line-height - $font-size) < ($min-line-padding * 2) {
      $lines: $lines + 1;
    }
    @include normalize-rhythm(line-height, $lines, $font-size);
  }