bulma/sass/elements/title.sass

$title-color: var(--text-strong, #{$text-strong}) !default
$title-family: false !default
$title-size: var(--size-3, #{$size-3}) !default
$title-weight: var(--weight-semibold, #{$weight-semibold}) !default
$title-line-height: 1.125 !default
$title-strong-color: inherit !default
$title-strong-weight: inherit !default
$title-sub-size: 0.75em !default
$title-sup-size: 0.75em !default

$subtitle-color: var(--text, #{$text}) !default
$subtitle-family: false !default
$subtitle-size: var(--size-5, #{$size-5}) !default
$subtitle-weight: var(--weight-normal, #{$weight-normal}) !default
$subtitle-line-height: 1.25 !default
$subtitle-strong-color: var(--text-strong, #{$text-strong}) !default
$subtitle-strong-weight: var(--weight-semibold, #{$weight-semibold}) !default
$subtitle-negative-margin: -1.25rem !default

.title,
.subtitle
  --title-sub-size: #{$title-sub-size}
  --title-sup-size: #{$title-sup-size}
  @extend %block
  word-break: break-word
  em,
  span
    font-weight: inherit
  sub
    font-size: var(--title-sub-size)
  sup
    font-size: var(--title-sup-size)
  .tag
    vertical-align: middle

.title
  // Approach A
  // CSS Variable takes precedence, if theme is included
  // --title-color: var(--text-strong, #{$title-color})
  // color: var(--title-color)

  // Approach B
  // Sass Variable takes precedence
  // Problem: --title-color is always set, so the fallback is never used
  // --title-color: #{$title-color}
  // color: var(--title-color, var(--text-strong))

  // Approach C
  // Sass variable references a CSS variable with fallback
  // $title-color: var(--text-strong, #{$text-strong})
  --title-color: #{$title-color}
  color: var(--title-color)

  --title-size: #{$title-size}
  --title-weight: #{$title-weight}
  --title-line-height: #{$title-line-height}
  --title-strong-color: #{$title-strong-color}
  --title-strong-weight: #{$title-strong-weight}
  font-size: var(--title-size)
  font-weight: var(--title-weight)
  line-height: var(--title-line-height)
  @if $title-family
    --title-family: #{$title-family}
    font-family: var(--title-family)
  strong
    color: var(--title-strong-color)
    font-weight: var(--title-strong-weight)
  & + .highlight
    margin-top: -0.75rem
  &:not(.is-spaced) + .subtitle
    margin-top: var(--subtitle-negative-margin)
  // Sizes
  @each $size in $sizes
    $i: index($sizes, $size)
    &.is-#{$i}
      font-size: $size

.subtitle
  --subtitle-negative-margin: #{$subtitle-negative-margin}
  --subtitle-color: #{$subtitle-color}
  --subtitle-size: #{$subtitle-size}
  --subtitle-weight: #{$subtitle-weight}
  --subtitle-line-height: #{$subtitle-line-height}
  --subtitle-strong-color: #{$subtitle-strong-color}
  --subtitle-strong-weight: #{$subtitle-strong-weight}
  color: var(--subtitle-color)
  font-size: var(--subtitle-size)
  font-weight: var(--subtitle-weight)
  line-height: var(--subtitle-line-height)
  @if $subtitle-family
    --subtitle-family: #{$subtitle-family}
    font-family: var(--subtitle-family)
  strong
    color: var(--subtitle-strong-color)
    font-weight: var(--subtitle-strong-weight)
  &:not(.is-spaced) + .title
    margin-top: var(--subtitle-negative-margin)
  // Sizes
  @each $size in $sizes
    $i: index($sizes, $size)
    &.is-#{$i}
      font-size: $size