.page-topics {
  --topics-hero-figure: calc(var(--text-figure) * 0.6);
  --topics-sub-figure: calc(var(--text-figure) * 0.5);
}

/* ---------- 首屏 ---------- */
.page-topics .topics-hero {
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}

.page-topics .topics-hero__inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: var(--space-6) var(--gutter) var(--space-8);
  display: grid;
  gap: var(--space-6);
}

.page-topics .topics-hero__narr {
  min-width: 0;
}

.page-topics .topics-hero .breadcrumbs {
  color: var(--color-contrast-ink);
  margin-bottom: var(--space-4);
}

.page-topics .topics-hero .breadcrumbs__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1);
  font-size: var(--text-sm);
  letter-spacing: 0.06em;
}

.page-topics .topics-hero .breadcrumbs__list li + li::before {
  content: "/";
  margin-right: var(--space-1);
  color: var(--color-contrast-line);
}

.page-topics .topics-hero .breadcrumbs a {
  color: var(--color-contrast-ink);
  text-decoration: none;
  border-bottom: var(--border-thin) solid var(--color-contrast-line);
}

.page-topics .topics-hero .breadcrumbs a:hover,
.page-topics .topics-hero .breadcrumbs a:focus-visible {
  color: var(--color-contrast-accent);
  border-bottom-color: var(--color-contrast-accent);
}

.page-topics .topics-hero .eyebrow {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--color-contrast-accent);
  margin: 0;
}

.page-topics .topics-hero__title {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-display);
  line-height: 1.04;
  letter-spacing: var(--tracking-heading);
  color: var(--color-contrast-ink);
  margin: var(--space-2) 0 var(--space-4);
  max-width: 14ch;
}

.page-topics .topics-hero__lead {
  margin: 0;
  max-width: 54ch;
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-contrast-ink);
  opacity: 0.86;
}

.page-topics .topics-hero__panel {
  position: relative;
  overflow: hidden;
  background: var(--color-primary);
  border: var(--border-thin) solid var(--color-contrast-line);
  border-left: var(--border-thick) solid var(--color-contrast-accent);
  min-height: 320px;
  display: flex;
  align-items: flex-end;
}

.page-topics .topics-hero__panel img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.55;
}

.page-topics .topics-hero__panel::after {
  content: "";
  position: absolute;
  inset: 0;
  background: var(--overlay-scrim);
  pointer-events: none;
}

.page-topics .topics-hero__panel-body {
  position: relative;
  z-index: 1;
  width: 100%;
  padding: var(--space-4);
}

.page-topics .topics-hero__panel-kicker {
  margin: 0 0 var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  letter-spacing: 0.2em;
  color: var(--color-contrast-ink);
  opacity: 0.72;
}

.page-topics .topics-hero__stats {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--space-2);
  margin: 0;
  padding-top: var(--space-3);
  border-top: var(--border-thin) solid var(--color-contrast-line);
}

.page-topics .topics-hero__stat {
  min-width: 0;
}

.page-topics .topics-hero__stat dt {
  font-size: var(--text-sm);
  letter-spacing: 0.1em;
  color: var(--color-contrast-ink);
  opacity: 0.7;
  margin-bottom: var(--space-1);
}

.page-topics .topics-hero__stat dd {
  margin: 0;
  font-family: var(--font-mono);
  font-weight: var(--weight-heading);
  font-size: var(--topics-hero-figure);
  line-height: 1;
  color: var(--color-contrast-accent);
  white-space: nowrap;
}

/* ---------- 页内目录条 ---------- */
.page-topics .topics-toc {
  position: sticky;
  top: 0;
  z-index: 6;
  background: var(--color-surface-deep);
  border-bottom: var(--border-thin) solid var(--color-line);
}

.page-topics .topics-toc__inner {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding-top: var(--space-2);
  padding-bottom: var(--space-2);
}

.page-topics .topics-toc__label {
  flex: 0 0 auto;
  display: none;
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  letter-spacing: 0.16em;
  color: var(--color-ink-muted);
  padding-right: var(--space-3);
  border-right: var(--border-thin) solid var(--color-line);
}

.page-topics .topics-toc__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  gap: var(--space-4);
  overflow-x: auto;
  scrollbar-width: none;
  -webkit-overflow-scrolling: touch;
}

.page-topics .topics-toc__list::-webkit-scrollbar {
  display: none;
}

.page-topics .topics-toc__link {
  display: block;
  white-space: nowrap;
  font-size: var(--text-sm);
  letter-spacing: 0.06em;
  color: var(--color-ink-soft);
  text-decoration: none;
  padding-bottom: 3px;
  border-bottom: var(--border-thick) solid transparent;
}

.page-topics .topics-toc__link:hover,
.page-topics .topics-toc__link:focus-visible,
.page-topics .topics-toc__link.is-active {
  color: var(--color-primary);
  border-bottom-color: var(--color-primary);
}

/* ---------- 专题区 ---------- */
.page-topics .topics-flow {
  background: var(--color-surface);
}

.page-topics .topics-group {
  border-top: var(--border-thick) solid var(--color-ink);
  padding-top: var(--space-4);
  margin-top: var(--space-8);
}

.page-topics .topics-group:first-of-type {
  margin-top: 0;
}

.page-topics .topics-group__head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: var(--space-3);
  align-items: start;
  margin-bottom: var(--space-4);
}

.page-topics .topics-group__num {
  font-size: var(--text-lg);
  font-weight: var(--weight-heading);
  line-height: 1;
  color: var(--color-accent);
}

.page-topics .topics-group__title {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
  margin: 0 0 var(--space-1);
}

.page-topics .topics-group__note {
  margin: 0;
  font-size: var(--text-sm);
  line-height: 1.6;
  color: var(--color-ink-soft);
  max-width: 48ch;
}

.page-topics .topics-group__grid {
  row-gap: var(--space-6);
}

.page-topics .topic-block {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  min-width: 0;
  padding: var(--space-3);
  background: var(--color-surface-alt);
  border: var(--border-thin) solid var(--color-line);
  border-top: var(--border-thick) solid var(--color-primary);
}

.page-topics .topic-block__cat {
  margin: 0;
  font-size: var(--text-xs);
  letter-spacing: 0.2em;
  color: var(--color-ink-muted);
}

.page-topics .topic-block__title {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
  margin: var(--space-1) 0 0;
}

.page-topics .topic-block__lead {
  margin: 0;
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
}

.page-topics .topic-block__points {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: var(--space-2);
}

.page-topics .topic-block__points li {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: var(--space-2);
  align-items: baseline;
  padding-left: var(--space-2);
  border-left: var(--border-thin) solid var(--color-primary);
  font-size: var(--text-base);
  line-height: 1.6;
  color: var(--color-ink);
}

.page-topics .topic-block__point-num {
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-accent);
}

.page-topics .topic-media {
  margin: 0;
}

.page-topics .topic-media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  border: var(--border-thin) solid var(--color-line);
}

.page-topics .topic-media figcaption {
  margin-top: var(--space-1);
  font-size: var(--text-xs);
  line-height: 1.55;
  color: var(--color-ink-muted);
}

.page-topics .topic-block__refs {
  display: flex;
  gap: var(--space-2);
  overflow-x: auto;
  margin-top: auto;
  padding-bottom: var(--space-1);
  scrollbar-width: thin;
  -webkit-overflow-scrolling: touch;
}

.page-topics .topic-ref {
  flex: 0 0 auto;
  display: inline-block;
  padding: var(--space-1) var(--space-2);
  background: var(--color-primary-soft);
  border: var(--border-thin) solid var(--color-primary);
  color: var(--color-primary);
  font-size: var(--text-sm);
  line-height: 1.4;
  text-decoration: none;
  white-space: nowrap;
}

.page-topics .topic-ref:hover,
.page-topics .topic-ref:focus-visible {
  background: var(--color-primary);
  color: var(--color-primary-ink);
}

/* ---------- 子页入口 ---------- */
.page-topics .topics-subpage {
  background: var(--color-surface-alt);
  border-top: var(--border-thick) solid var(--color-accent);
}

.page-topics .topics-subpage__inner {
  display: grid;
  gap: var(--space-6);
  padding: var(--space-6) var(--space-4);
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border-left: var(--border-thick) solid var(--color-contrast-accent);
}

.page-topics .topics-subpage__eyebrow {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  letter-spacing: 0.24em;
  color: var(--color-contrast-accent);
  margin: 0;
}

.page-topics .topics-subpage__title {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-xl);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-contrast-ink);
  margin: var(--space-2) 0 var(--space-3);
}

.page-topics .topics-subpage__lead {
  margin: 0 0 var(--space-4);
  max-width: 58ch;
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-contrast-ink);
  opacity: 0.86;
}

.page-topics .topics-subpage__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--space-3);
  margin: 0;
  padding-top: var(--space-4);
  border-top: var(--border-thin) solid var(--color-contrast-line);
}

.page-topics .topics-subpage__stat {
  min-width: 0;
}

.page-topics .topics-subpage__stat dt {
  font-size: var(--text-sm);
  letter-spacing: 0.08em;
  color: var(--color-contrast-ink);
  opacity: 0.7;
  margin-bottom: var(--space-1);
}

.page-topics .topics-subpage__stat dd {
  margin: 0;
  font-family: var(--font-mono);
  font-weight: var(--weight-heading);
  font-size: var(--topics-sub-figure);
  line-height: 1;
  color: var(--color-contrast-accent);
  white-space: nowrap;
}

.page-topics .topics-subpage__stat .topics-subpage__stat-text {
  font-size: var(--text-lg);
  color: var(--color-contrast-ink);
}

.page-topics .topics-subpage .btn--accent {
  border-radius: var(--radius-lg);
}

/* ---------- 选题来源 ---------- */
.page-topics .topics-source {
  background: var(--color-surface);
}

.page-topics .topics-source__grid {
  row-gap: var(--space-6);
}

.page-topics .topics-source__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0;
}

.page-topics .topics-source__item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: var(--space-3);
  align-items: start;
  padding: var(--space-3) 0;
  border-top: var(--border-thin) solid var(--color-line);
}

.page-topics .topics-source__item:last-child {
  border-bottom: var(--border-thin) solid var(--color-line);
}

.page-topics .topics-source__num {
  font-size: var(--text-sm);
  font-weight: var(--weight-heading);
  letter-spacing: 0.1em;
  color: var(--color-accent);
  padding-top: 4px;
}

.page-topics .topics-source__item-title {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-base);
  line-height: var(--leading-heading);
  color: var(--color-ink);
  margin: 0 0 var(--space-1);
}

.page-topics .topics-source__item p {
  margin: 0;
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
  max-width: var(--measure);
}

.page-topics .topics-source__aside {
  background: var(--color-primary-soft);
  border: var(--border-thin) solid var(--color-primary);
  padding: var(--space-4);
}

.page-topics .topics-source__aside-title {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-primary);
  margin: 0 0 var(--space-2);
}

.page-topics .topics-source__aside-lead {
  margin: 0 0 var(--space-3);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink);
}

.page-topics .topics-source__links {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: var(--space-2);
}

.page-topics .topics-source__links li {
  border-top: var(--border-thin) solid var(--color-primary);
  padding-top: var(--space-2);
}

.page-topics .topics-source__links a {
  display: block;
  font-size: var(--text-sm);
  line-height: 1.5;
  color: var(--color-ink);
  text-decoration: none;
  padding-left: var(--space-2);
  border-left: var(--border-thick) solid var(--color-accent);
}

.page-topics .topics-source__links a:hover,
.page-topics .topics-source__links a:focus-visible {
  color: var(--color-primary);
  border-left-color: var(--color-primary);
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-topics .topics-toc__label {
    display: block;
  }

  .page-topics .topics-subpage__inner {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr);
    align-items: start;
    padding: var(--space-8) var(--space-6);
  }

  .page-topics .topics-subpage__stats {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    border-top: none;
    border-left: var(--border-thin) solid var(--color-contrast-line);
    padding-top: 0;
    padding-left: var(--space-4);
  }
}

@media (min-width: 1000px) {
  .page-topics .topics-hero__inner {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    align-items: stretch;
    padding-top: var(--space-8);
    padding-bottom: var(--space-8);
  }

  .page-topics .topics-hero__panel {
    min-height: 460px;
  }

  .page-topics .topics-group__head {
    gap: var(--space-4);
  }

  .page-topics .topics-group__title {
    font-size: var(--text-xl);
  }

  .page-topics .topics-group__num {
    font-size: var(--text-xl);
  }

  .page-topics .topics-source__aside {
    padding: var(--space-6) var(--space-4);
  }
}