discourse/app/assets/stylesheets/common/base/_topic-list.scss

// Topic list navigation & controls

.list-controls {
  background: var(--d-content-background);

  .combo-box .combo-box-header {
    background: var(--secondary);
    color: var(--primary);
    border: 1px solid var(--primary-medium);
    font-size: var(--font-0);
    transition: none;
    height: 100%;
    &:focus {
      border-color: var(--tertiary);
    }
  }
  .select-kit {
    .select-kit-collection {
      max-height: 40vh;
    }
  }
}

.navigation-container {
  width: 100%;
  --nav-space: 0.75em;
  display: flex;
  flex-wrap: wrap;
}

.category-breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: var(--nav-space) 0; // used if the breadcrumb dropdowns wrap
  list-style: none;
  padding: 0;
  margin: 0 0 var(--nav-space) 0;
  > li {
    // only target the top-level li, not dropdowns
    display: flex;
    margin-right: 0.5em;
    margin-bottom: 0;
  }
}

#navigation-bar {
  display: flex;
  flex-wrap: wrap;
  margin: 0;
  margin-bottom: var(--nav-space);
  margin-right: auto;
}

.navigation-controls {
  display: flex;
  flex-wrap: wrap;
  align-items: stretch;
  margin-bottom: var(--nav-space);
  gap: var(--nav-space) 0; // used if the buttons wrap
  > * {
    white-space: nowrap;
    &:not(:last-child) {
      margin-right: 0.5em;
    }
  }
  .select-kit-header {
    height: 100%;
  }
  @include breakpoint(mobile-large) {
    .edit-category {
      .d-button-label {
        display: none;
      }
      .d-icon {
        margin: 0;
      }
    }
  }
}

.category-heading {
  max-width: 100%;
  p {
    margin-top: 0;
    line-height: var(--line-height-large);
    font-size: var(--font-up-3);
  }
}

.category-logo.aspect-image {
  width: auto;
  max-height: 150px;
}

@supports (--custom: property) {
  .category-logo.aspect-image {
    --max-height: 150px;
    max-height: var(--max-height);
    max-width: 100%;
    height: auto;

    img {
      width: calc(var(--max-height) * var(--aspect-ratio));
      max-width: 100%;
      height: inherit;
      max-height: var(--max-height);
    }
  }
}

.topic-list.shared-drafts {
  margin-bottom: 1.5em;
}

#header-list-area {
  background: var(--d-content-background);
}

// Topic list body

.topic-list-item.visited .topic-list-data,
.latest-topic-list-item.visited,
.category-topic-link.visited {
  a.title:not(.badge-notification) {
    color: var(--primary-medium);
  }
  .badge-category {
    color: var(--primary-medium);
  }
  .discourse-tag,
  .discourse-tag:visited {
    color: var(--primary-medium);
  }
}

.topic-list-item {
  .post-excerpt {
    margin-top: 0.5em;
    margin-bottom: 0.5em;
    font-size: var(--font-down-2);
    word-break: break-word;
  }
}

.topic-list-main-link {
  font-size: var(--font-up-1);
  a.title {
    padding: 15px 0;
    word-break: break-word;
    color: var(--primary);
  }

  .anon & {
    a.title:visited:not(.badge-notification) {
      color: var(--primary-medium);
    }
  }

  a.title.visited:not(.badge-notification) {
    color: var(--primary-medium);
  }
}

.sticky-header .topic-list-header {
  @include sticky;
  top: var(--header-offset, 60px);
  background: var(--secondary);
  z-index: 2;
}

.topic-list {
  width: 100%;
  border-collapse: collapse;

  > .topic-list-body > .topic-list-item {
    &.has-excerpt .star {
      vertical-align: top;
      margin-top: 2px;
    }

    &.last-visit {
      border-bottom: none;
    }

    .topic-list-separator {
      text-align: center;
    }
  }

  .topic-list-item-separator {
    border: none;

    .topic-list-data {
      border-top: 1px solid var(--danger-medium);
      line-height: 0em;
      padding: 0;
      text-align: center;
    }

    .topic-list-data span {
      position: relative; // Chrome needs this, otherwise the line is above the text
      background-color: var(--secondary);
      color: var(--danger-medium);
      padding: 0 8px;
      font-size: var(--font-down-1);
    }
  }

  .topic-list-data {
    line-height: var(--line-height-large);
    text-align: left;
    vertical-align: middle;
  }
  .btn-flat .d-icon {
    color: currentColor;
  }

  td {
    color: var(--primary-medium);
    font-size: var(--font-0);
  }

  .main-link {
    @extend .topic-list-main-link;

    .raw-topic-link > * {
      // important to prevent clicks registering on non-link elements and resulting in a full page reload
      pointer-events: none;
    }

    &.focused {
      box-shadow: inset 3px 0 0 var(--tertiary);
    }
    /* we have a custom focus indicator so we can remove the native one */
    .title:focus {
      outline: none;
    }
    .title:focus-visible {
      outline: none;
    }
  }

  .unread-indicator {
    &.read {
      display: none;
    }
    .d-icon {
      vertical-align: middle;
      font-size: var(--font-down-5);
    }
  }

  .link-bottom-line {
    font-size: var(--font-down-1);
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 0.5em;
    .discourse-tags {
      flex-wrap: wrap;
    }
    a.discourse-tag.box {
      padding-top: 0;
      padding-bottom: 0;
    }
    .discourse-tag.box {
      margin-right: 0.25em;
    }

    .participant-group-wrapper {
      display: flex;
      margin-left: 0.5em;

      .participant-group {
        padding: 0 5px;
        border: 1px solid var(--primary-low);
        border-radius: 0.25em;
        min-width: 3em;
        @include ellipsis;

        > a {
          display: flex;
          align-items: center;
          height: 1.25em;
          color: var(--primary-high);
          .mobile-view & {
            height: 1.1em;
          }
          .d-icon {
            margin-right: 5px;
          }
        }
      }
    }
  }

  .topic-excerpt {
    display: block;
    font-size: var(--font-down-1);
    margin-top: 0.33em;
    color: var(--primary-high);
    word-wrap: break-word;
    line-height: var(--line-height-large);
    padding-right: 20px;
  }

  .num {
    text-align: center;

    a {
      color: inherit;
    }

    .badge-posts {
      font-weight: 700;
      color: inherit;
      padding: 15px 5px;
    }
  }

  .num.posts {
    a {
      padding: 15px 5px;
    }
  }

  .num.activity {
    a {
      padding: 15px 5px;
      span.relative-date {
        pointer-events: none;
      }
    }
  }
}

.heatmap-high,
.heatmap-high a,
.heatmap-high .d-icon,
.heatmap-high .d-button-label {
  color: #fe7a15 !important;
}

.heatmap-med,
.heatmap-med a,
.heatmap-med .d-icon,
.heatmap-med .d-button-label {
  color: #cf7721 !important;
}

.heatmap-low,
.heatmap-low a,
.heatmap-low .d-icon,
.heatmap-low .d-button-label {
  color: #9b764f !important;
}

.topic-list .heatmap-high {
  font-weight: bold;
}

.loading .topic-list {
  border: 0;
  box-shadow: none;
  .topic-list-item {
    background-color: transparent;
  }
}

#list-area {
  background: var(--d-content-background);
  margin-bottom: 100px;

  .empty-topic-list {
    padding: 10px;
  }

  .unseen {
    background-color: transparent;
    padding: 0;
    border: 0;
    color: var(--danger-medium);
    font-size: var(--font-0);
    cursor: default;
  }
}

.topic-list {
  .alert {
    margin-bottom: 0;
    font-size: var(--font-0);
  }
  .spinner {
    margin-top: 40px;
  }
}

.d-icon-thumbtack.unpinned {
  @include fa-rotate(180deg, 1);
}

.top-title-buttons {
  display: flex;
  margin: 0.5em 0;
  flex-wrap: wrap;
  font-size: var(--font-down-1);
  gap: 0.5em;
}

div.education {
  color: var(--primary);
  margin-bottom: 2em;

  p {
    max-width: 62em;
  }

  .badge-notification {
    vertical-align: text-bottom;
  }
}

.list-cell {
  padding: 12px 5px;
  color: var(--primary-med-or-secondary-high);
}

.table-heading {
  @extend .list-cell;
  border-bottom: 3px solid var(--primary-low);
}

// This is not what we want:
//
//     This is an overly-long topic title that would break just right
//     *
//
// Instead, we want the line to break like this:
//
//     This is an overly-long topic title that would break just
//     right *
.topic-post-badges {
  white-space: nowrap;
  align-self: center;
  line-height: var(--line-height-medium);
}