content/assets/stylesheets/toc.scss

@use 'variables' as *;
@use 'utilities' as *;

$base-nav-link-padding: 0.75rem;
$sm-nav-link-padding: 0.25rem;
$nav-link-font-size: 0.875rem;

@mixin nav-link-toc-level($i) {
  padding-left: $base-nav-link-padding * ($i + 0.75);
  padding-top: 0;
  line-height: 1rem;
}

@mixin toc-nav-link {
  font-size: $nav-link-font-size;
  color: $toc-link-color;
  border-radius: 0;
  border-left: 3px solid $gds-indigo-100;
  border-bottom: 0;

  &:hover {
    color: $link-color-nav-hover;
    text-decoration: underline;
    background-color: transparent;
    box-shadow: none;
    border-bottom: 0;
  }

  &.active {
    color: $link-color-nav;
    background-color: transparent;
    border-color: $gds-indigo-800;

    /* stylelint-disable-next-line selector-list-comma-newline-after */
    &:hover, &:only-child {
      color: $link-color-nav-hover;
      background-color: transparent;
    }
  }
}

// ToC styles
.table-of-contents {
  padding: 0.5rem 1rem 0;

  li {
    list-style: none;
  }

  .nav-link {
    @include toc-nav-link;
  }
}

// ToC before JavaScript loads
#markdown-toc {
  position: absolute;
  top: $header-height;
  right: 0;
  padding-top: calc(4.75rem + 1.375rem * 1.125);
  padding-left: 3rem;
  margin: 0;
  transform: translateX(100%);
  overflow-x: hidden;
  overflow-y: scroll;
  width: calc(25vw - 1rem); // max scrollbar size

  code {
    all: revert;
    font: inherit;
  }

  a {
    display: block;
    padding: 0 1rem 0.5rem;
    line-height: 1rem;

    @include toc-nav-link;
  }

  ul,
  li {
    list-style: none;
    margin: 0;
    padding: 0;
    line-height: 1;
  }
}

.markdown-toc {
  top: $header-height;

  @media(min-width: $bp-xl) {
    padding-left: 1rem;
    margin-bottom: 1.5rem;
    overflow-y: scroll;
    height: 100vh;
  }

  @media(max-width: calc($bp-xl - 1px)) {
    margin-top: 6rem;
  }
}

.nav-pills {
  flex-wrap: nowrap;
}

// NOTE: This only allows for 10 levels.
// This should be acceptable since levels are determined by the `<h1-6>` which is less
// than 10 anyways...
@for $i from 0 to 10 {
  .nav-link.toc-level-#{$i} {
    @include nav-link-toc-level($i);
  }

  #markdown-toc #{repeat-str('ul', $i)} a {
    @include nav-link-toc-level($i);
  }
}

@media(max-width: calc($bp-xl - 1px)) {
  .doc-nav {
    margin-left: -20px;
    margin-top: -55px;
    position: relative;
    z-index: 1;
  }

  .table-of-contents {
    padding: 0 1rem;
    font-size: 0.875rem;

    .nav-link {
      border-left: 0;
      padding: $sm-nav-link-padding;
    }

    h4 {
      font-size: $nav-link-font-size;
    }
  }

  .sm-collapsing {
    height: 0;
    overflow: hidden;
    transition: height 0.2s ease;
  }

  .sm-collapsed {
    display: none;
  }

  .toc-lg {
    display: none;
  }

  .toc-sm {
    display: block;
  }
}

// wide enough to show toc but not quick nav
@media(min-width: $bp-xl) {
  .header {
    top: 0;
    left: 0;
  }

  .doc-nav {
    &.toc-no-breadcrumbs {
      padding-top: 6px;
    }
  }

  .toc-lg {
    display: block;
  }

  .toc-sm {
    display: none;
  }
}