sass-site/source/assets/css/foundation/_headings.scss

#{headings(1, 4)} { @extend %reset-margin; }

#{headings(1, 2)} {
  @include font-size-large;
  @include adjust-leading-to(1, $font-size-large);
  font-weight: $font-weight-light;
  letter-spacing: -0.03125em;
  color: $color-accent;

  @include breakpoint($tablet-small) { @include font-size-x-large; }
  @include breakpoint($tablet-large) { @include font-size-xx-large; }
}

h1 {
  font-weight: $font-weight-light;
  color: $color-text-heading;

  @include breakpoint($screen-small) { @include font-size-xxx-large; }
  @include breakpoint($screen-large) { @include font-size-xxxx-large; }
}

h2 {
  @include padding-leader(2, $font-size-large);
  @include padding-trailer(1, $font-size-large);

  .main &:first-child { padding-top: 0; }

  @include breakpoint($tablet-small) {
    @include padding-leader(2, $font-size-x-large);
    @include padding-trailer(1, $font-size-x-large);
  }

  @include breakpoint($tablet-large) {
    @include padding-leader(2, $font-size-xx-large);
    @include padding-trailer(1, $font-size-xx-large);
  }
}

h2,
h3 { font-family: $font-family-display; }

#{headings(3, 4)} {
  @include padding-leader(1.5);
  @include padding-trailer(.5);
  @include font-size-regular;
  font-weight: $font-weight-bold;
  text-transform: uppercase;
  letter-spacing: .03125em;
  color: $color-text-weak;
  white-space: nowrap;
}