.aibook-categories-page {
  --category-surface: #fff;
  --category-surface-soft: #f7f9fb;
  --category-text: #1e2835;
  --category-muted: #5f6b78;
  --category-border: #dfe5ec;
  --category-link: #075e8f;
  color: var(--category-text);
  letter-spacing: 0;
}

.aibook-categories-page *,
.aibook-categories-page *::before,
.aibook-categories-page *::after {
  box-sizing: border-box;
}

.aibook-categories-page a {
  text-decoration: none;
}

.aibook-categories-page a:hover {
  text-decoration: none;
}

.aibook-categories-hero {
  padding: 4px 0 24px;
  border-bottom: 1px solid var(--category-border);
}

.aibook-categories-hero h1 {
  margin: 0;
  color: var(--category-text);
  font-size: 40px;
  font-weight: 760;
  line-height: 1.25;
}

.aibook-categories-hero > p {
  max-width: 920px;
  margin: 10px 0 0;
  color: var(--category-muted);
  font-size: 17px;
  line-height: 1.75;
}

.aibook-categories-facts {
  display: flex;
  flex-wrap: wrap;
  margin-top: 15px;
  color: #697581;
  font-size: 13px;
}

.aibook-categories-facts span {
  display: inline-flex;
  align-items: center;
}

.aibook-categories-facts span + span::before {
  width: 3px;
  height: 3px;
  margin: 0 12px;
  border-radius: 50%;
  background: #aeb8c2;
  content: "";
}

.aibook-categories-overview,
.aibook-categories-catalog {
  padding: 30px 0;
  border-bottom: 1px solid var(--category-border);
}

.aibook-categories-catalog {
  padding-top: 38px;
  border-bottom: 0;
}

.aibook-categories-heading {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(280px, 0.72fr);
  gap: 32px;
  align-items: end;
  margin-bottom: 14px;
}

.aibook-categories-heading-catalog {
  margin-bottom: 18px;
}

.aibook-categories-label {
  display: block;
  margin: 0 0 7px;
  color: #087a91;
  font-size: 13px;
  font-weight: 760;
}

.aibook-categories-heading h2 {
  margin: 0;
  color: var(--category-text);
  font-size: 26px;
  font-weight: 740;
  line-height: 1.35;
}

.aibook-categories-heading > p {
  margin: 0 0 2px;
  color: var(--category-muted);
  font-size: 14px;
  line-height: 1.65;
}

.aibook-categories-overview-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 12px;
}

.aibook-category-overview-card {
  position: relative;
  display: flex;
  min-width: 0;
  min-height: 210px;
  flex-direction: column;
  padding: 16px 18px 14px;
  overflow: hidden;
  border: 1px solid var(--category-border);
  border-radius: 6px;
  background: var(--category-surface);
  color: var(--category-text);
}

.aibook-category-overview-card:hover {
  border-color: color-mix(in srgb, var(--category-accent) 48%, var(--category-border));
  box-shadow: 0 8px 18px rgba(31, 45, 61, 0.08);
}

.aibook-category-overview-card:focus-visible {
  outline: 3px solid color-mix(in srgb, var(--category-accent) 30%, transparent);
  outline-offset: 2px;
}

.aibook-category-card-line {
  position: absolute;
  top: 0;
  right: 0;
  left: 0;
  height: 3px;
  background: var(--category-accent);
}

.aibook-category-card-index {
  align-self: flex-start;
  margin: 2px 0 8px;
  color: var(--category-accent);
  font-size: 12px;
  font-weight: 780;
}

.aibook-category-overview-card h3 {
  margin: 0;
  color: var(--category-accent);
  font-size: 20px;
  font-weight: 740;
  line-height: 1.35;
}

.aibook-category-overview-card p {
  display: -webkit-box;
  min-height: 63px;
  margin: 8px 0 10px;
  overflow: hidden;
  color: #4f5b68;
  font-size: 13px;
  line-height: 1.62;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 3;
}

.aibook-category-card-stats {
  margin-top: auto;
  color: #697581;
  font-size: 12px;
  font-weight: 650;
}

.aibook-category-card-chapters {
  display: -webkit-box;
  margin-top: 8px;
  overflow: hidden;
  color: var(--category-accent);
  font-size: 12px;
  line-height: 1.55;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 2;
}

.aibook-category-band {
  display: grid;
  grid-template-columns: minmax(210px, 0.72fr) minmax(0, 2.28fr);
  gap: 22px;
  padding: 38px 0;
  border-bottom: 1px solid var(--category-border);
  scroll-margin-top: 88px;
}

.aibook-category-band:last-child {
  border-bottom: 0;
}

.aibook-category-band-summary {
  align-self: start;
  padding-left: 16px;
  border-left: 4px solid var(--category-accent);
}

.aibook-category-band-index {
  display: block;
  color: var(--category-accent);
  font-size: 12px;
  font-weight: 780;
}

.aibook-category-band-summary h2 {
  margin: 6px 0 10px;
  font-size: 26px;
  line-height: 1.3;
}

.aibook-category-band-summary h2 a {
  color: var(--category-text);
}

.aibook-category-band-summary h2 a:hover {
  color: var(--category-accent);
}

.aibook-category-band-summary p {
  margin: 0;
  color: #53606d;
  font-size: 14px;
  line-height: 1.72;
}

.aibook-category-band-facts {
  display: flex;
  gap: 22px;
  margin: 18px 0 0;
}

.aibook-category-band-facts div {
  min-width: 42px;
}

.aibook-category-band-facts dt {
  color: #7b8691;
  font-size: 11px;
  font-weight: 400;
}

.aibook-category-band-facts dd {
  margin: 1px 0 0;
  color: var(--category-accent);
  font-size: 17px;
  font-weight: 760;
}

.aibook-category-chapter-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  align-items: start;
}

.aibook-category-chapter {
  min-width: 0;
  min-height: 132px;
  border: 1px solid var(--category-border);
  border-radius: 6px;
  background: var(--category-surface);
}

.aibook-category-chapter-leaf {
  display: flex;
  flex-direction: column;
  padding: 15px 15px 13px;
}

.aibook-category-chapter-title {
  color: var(--category-text);
  font-size: 15px;
  font-weight: 740;
  line-height: 1.45;
}

a.aibook-category-chapter-title {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 8px;
}

a.aibook-category-chapter-title:hover {
  color: var(--category-accent);
}

.aibook-category-external-mark {
  flex: 0 0 auto;
  color: var(--category-accent);
  font-size: 12px;
}

.aibook-category-chapter p,
.aibook-category-chapter-description {
  color: #66717d;
  font-size: 12px;
  line-height: 1.58;
}

.aibook-category-chapter-leaf p {
  display: -webkit-box;
  margin: 7px 0 9px;
  overflow: hidden;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 2;
}

.aibook-category-chapter-meta {
  display: block;
  margin-top: auto;
  color: var(--category-accent);
  font-size: 11px;
  font-weight: 680;
}

.aibook-category-chapter-branch {
  overflow: hidden;
}

.aibook-category-chapter-branch[open] {
  grid-column: span 2;
  border-color: color-mix(in srgb, var(--category-accent) 34%, var(--category-border));
}

.aibook-category-chapter summary {
  display: flex;
  min-height: 130px;
  align-items: flex-start;
  justify-content: space-between;
  gap: 10px;
  padding: 15px;
  cursor: pointer;
  list-style: none;
}

.aibook-category-chapter summary::-webkit-details-marker {
  display: none;
}

.aibook-category-chapter-summary-copy {
  display: flex;
  min-width: 0;
  flex: 1;
  flex-direction: column;
}

.aibook-category-chapter-description {
  display: -webkit-box;
  margin-top: 7px;
  overflow: hidden;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 2;
}

.aibook-category-chapter-summary-copy .aibook-category-chapter-meta {
  margin-top: 9px;
}

.aibook-category-chapter-chevron {
  display: grid;
  width: 24px;
  height: 24px;
  flex: 0 0 auto;
  place-items: center;
  color: var(--category-accent);
  font-size: 13px;
  transition: transform 160ms ease;
}

.aibook-category-chapter[open] .aibook-category-chapter-chevron {
  transform: rotate(180deg);
}

.aibook-category-chapter-expanded {
  padding: 0 15px 15px;
  border-top: 1px solid var(--category-border);
}

.aibook-category-chapter-enter {
  display: inline-flex;
  margin: 12px 0 7px;
  align-items: center;
  gap: 4px;
  color: var(--category-accent);
  font-size: 12px;
  font-weight: 700;
}

.aibook-category-branch-list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.aibook-category-branch-list .aibook-category-branch-list {
  margin-left: 10px;
  padding-left: 12px;
  border-left: 1px solid var(--category-border);
}

.aibook-category-branch-row {
  display: flex;
  min-width: 0;
  align-items: baseline;
  justify-content: space-between;
  gap: 10px;
  padding: 6px 0;
  border-top: 1px dashed #e4e9ee;
}

.aibook-category-branch-list > li:first-child > .aibook-category-branch-row {
  border-top: 0;
}

.aibook-category-branch-row a {
  min-width: 0;
  color: #354453;
  font-size: 12px;
  font-weight: 650;
}

.aibook-category-branch-row a:hover {
  color: var(--category-accent);
}

.aibook-category-branch-row span {
  flex: 0 0 auto;
  color: #7b8691;
  font-size: 10px;
  white-space: nowrap;
}

.aibook-category-theme-basic {
  --category-accent: #0f766e;
}

.aibook-category-theme-computing-resources {
  --category-accent: #a16207;
}

.aibook-category-theme-llm {
  --category-accent: #155eaa;
}

.aibook-category-theme-ai-develop {
  --category-accent: #5b4ab0;
}

.aibook-category-theme-ai-use {
  --category-accent: #2f7d32;
}

.aibook-category-theme-ai-safe-and-rules {
  --category-accent: #b33a3a;
}

.aibook-category-theme-news {
  --category-accent: #536270;
}

@media (max-width: 1199px) {
  .aibook-categories-overview-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .aibook-category-band {
    grid-template-columns: 1fr;
  }

  .aibook-category-band-summary {
    max-width: 760px;
  }
}

@media (max-width: 767px) {
  .aibook-categories-hero h1 {
    font-size: 34px;
  }

  .aibook-categories-heading {
    grid-template-columns: 1fr;
    gap: 6px;
    align-items: start;
  }

  .aibook-categories-overview-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 9px;
  }

  .aibook-category-overview-card {
    min-height: 206px;
    padding: 15px 14px 13px;
  }

  .aibook-category-overview-card h3 {
    font-size: 18px;
  }
}

@media (max-width: 575px) {
  .aibook-categories-hero {
    padding-top: 0;
  }

  .aibook-categories-hero h1 {
    font-size: 31px;
  }

  .aibook-categories-hero > p {
    font-size: 15px;
  }

  .aibook-categories-heading h2 {
    font-size: 23px;
  }

  .aibook-category-overview-card {
    min-height: 200px;
    padding-right: 12px;
    padding-left: 12px;
  }

  .aibook-category-overview-card h3 {
    font-size: 17px;
  }

  .aibook-category-overview-card p {
    min-height: 61px;
    font-size: 12px;
  }

  .aibook-category-card-stats {
    line-height: 1.5;
  }

  .aibook-category-card-chapters {
    display: none;
  }

  .aibook-category-band {
    padding: 32px 0;
    scroll-margin-top: 72px;
  }

  .aibook-category-band-summary {
    padding-left: 13px;
  }

  .aibook-category-band-summary h2 {
    font-size: 24px;
  }

  .aibook-category-chapter-grid {
    grid-template-columns: 1fr;
  }

  .aibook-category-chapter-branch[open] {
    grid-column: auto;
  }

  .aibook-category-chapter,
  .aibook-category-chapter summary {
    min-height: 124px;
  }
}

@media (prefers-color-scheme: dark) {
  html:not([data-mode]) .aibook-categories-page {
    color-scheme: dark;
    --category-surface: #1b2229;
    --category-surface-soft: #222a32;
    --category-text: #e7edf3;
    --category-muted: #b7c1cb;
    --category-border: #39434d;
  }

  html:not([data-mode]) .aibook-category-overview-card p,
  html:not([data-mode]) .aibook-category-band-summary p,
  html:not([data-mode]) .aibook-category-chapter p,
  html:not([data-mode]) .aibook-category-chapter-description,
  html:not([data-mode]) .aibook-category-branch-row a {
    color: #c2cbd4;
  }

  html:not([data-mode]) .aibook-category-branch-row {
    border-top-color: #333d46;
  }
}

html[data-mode="dark"] .aibook-categories-page {
  color-scheme: dark;
  --category-surface: #1b2229;
  --category-surface-soft: #222a32;
  --category-text: #e7edf3;
  --category-muted: #b7c1cb;
  --category-border: #39434d;
}

html[data-mode="dark"] .aibook-category-overview-card p,
html[data-mode="dark"] .aibook-category-band-summary p,
html[data-mode="dark"] .aibook-category-chapter p,
html[data-mode="dark"] .aibook-category-chapter-description,
html[data-mode="dark"] .aibook-category-branch-row a {
  color: #c2cbd4;
}

html[data-mode="dark"] .aibook-category-branch-row {
  border-top-color: #333d46;
}