.page-topics {
  display: block;
  background: var(--color-surface);
  color: var(--color-ink);
}

/* ============ 首屏封面 ============ */
.page-topics .topics-hero {
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  padding: var(--space-6) 0 var(--space-8);
  border-radius: 0 0 var(--radius-lg) var(--radius-lg);
}

.page-topics .topics-hero .breadcrumb__link {
  color: var(--color-contrast-ink);
  opacity: 0.72;
}

.page-topics .topics-hero .breadcrumb__current {
  color: var(--color-contrast-accent);
}

.page-topics .topics-hero__eyebrow {
  margin: var(--space-4) 0 var(--space-3);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.16em;
  color: var(--color-contrast-accent);
}

.page-topics .topics-hero__title {
  margin: 0 0 var(--space-6);
  font-family: var(--font-heading);
  font-size: var(--text-display);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-contrast-ink);
  max-width: 20em;
}

.page-topics .topics-hero__grid {
  display: grid;
  gap: var(--space-6);
}

.page-topics .topics-hero__lede > p {
  margin: 0 0 var(--space-6);
  font-size: var(--text-lg);
  line-height: var(--leading-body);
  color: var(--color-contrast-ink);
  max-width: 44ch;
}

.page-topics .topics-hero__figures {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-4) var(--space-6);
  margin: 0;
  padding: var(--space-3) 0 0;
  border-top: var(--border-thin) solid var(--color-contrast-line);
  list-style: none;
}

.page-topics .topics-hero__figure {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  min-width: 0;
}

.page-topics .topics-hero__figure .figure-number {
  font-family: var(--font-mono);
  font-size: var(--text-figure);
  font-weight: var(--weight-heading);
  line-height: 1;
  color: var(--color-contrast-ink);
}

.page-topics .topics-hero__figlabel {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: color-mix(in srgb, var(--color-contrast-ink) 62%, transparent);
}

.page-topics .topics-hero__index {
  display: grid;
  gap: var(--space-2);
  align-content: start;
}

.page-topics .topics-hero__index-link {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-md);
  background: var(--color-primary-soft);
  color: var(--color-ink);
  text-decoration: none;
  transition: background-color 220ms ease, color 220ms ease;
}

.page-topics .topics-hero__index-link:hover,
.page-topics .topics-hero__index-link:focus-visible {
  background: var(--color-primary);
  color: var(--color-primary-ink);
  outline: none;
}

.page-topics .topics-hero__index-no {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-accent);
  border-bottom: var(--border-thin) solid currentColor;
}

.page-topics .topics-hero__index-link:hover .topics-hero__index-no,
.page-topics .topics-hero__index-link:focus-visible .topics-hero__index-no {
  color: var(--color-primary-ink);
}

.page-topics .topics-hero__index-name {
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: var(--weight-heading);
  color: inherit;
}

.page-topics .topics-hero__index-count {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: inherit;
  opacity: 0.72;
}

.page-topics .topics-find {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2) var(--space-3);
  margin-top: var(--space-6);
  padding-top: var(--space-4);
  border-top: var(--border-thin) solid var(--color-contrast-line);
}

.page-topics .topics-find__label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-contrast-accent);
}

.page-topics .topics-find__input {
  flex: 1 1 220px;
  min-width: 0;
  padding: var(--space-2) var(--space-3);
  border: var(--border-thin) solid var(--color-contrast-line);
  border-radius: var(--radius-sm);
  background: transparent;
  color: var(--color-contrast-ink);
  font-family: var(--font-mono);
  font-size: var(--text-sm);
}

.page-topics .topics-find__input::placeholder {
  color: color-mix(in srgb, var(--color-contrast-ink) 52%, transparent);
}

.page-topics .topics-find__input:focus-visible {
  outline: var(--border-thin) solid var(--color-focus);
  outline-offset: 2px;
}

.page-topics .topics-hero__media {
  margin: var(--space-6) 0 0;
  border-radius: var(--radius-lg);
  overflow: hidden;
  aspect-ratio: 5 / 3;
  background: var(--color-contrast-line);
}

.page-topics .topics-hero__media img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(0.8) contrast(1.06);
}

/* ============ 专题分组 ============ */
.page-topics .topics-group {
  padding: var(--section-y) 0 0;
}

.page-topics .topics-list {
  display: grid;
  gap: var(--space-6);
  margin-top: var(--space-6);
}

.page-topics .topic-block {
  padding-top: var(--space-4);
  border-top: var(--border-thin) solid var(--color-line);
}

.page-topics .topics-list > .topic-block:first-child {
  padding-top: 0;
  border-top: 0;
}

.page-topics .topic-block__no {
  margin: 0 0 var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
  color: var(--color-accent);
}

.page-topics .topic-block__title {
  margin: 0 0 var(--space-4);
  font-family: var(--font-heading);
  font-size: var(--text-2xl);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
  max-width: 22em;
}

.page-topics .topic-block__body {
  display: grid;
  gap: var(--space-4);
}

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

.page-topics .topic-block__points {
  list-style: none;
  counter-reset: topic-point;
  margin: 0;
  padding: 0;
  display: grid;
  gap: var(--space-3);
}

.page-topics .topic-block__points li {
  counter-increment: topic-point;
  position: relative;
  padding-left: var(--space-4);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink);
}

.page-topics .topic-block__points li::before {
  content: counter(topic-point, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 0.4em;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-primary);
}

.page-topics .topic-block__media {
  margin: var(--space-4) 0 0;
  border-radius: var(--radius-md);
  overflow: hidden;
  aspect-ratio: 16 / 10;
}

.page-topics .topic-block__media img,
.page-topics .topics-band__media img,
.page-topics .topics-cycle__media img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.page-topics .topic-block__links {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2) var(--space-4);
  margin-top: var(--space-4);
  padding-top: var(--space-3);
  border-top: var(--border-thin) solid var(--color-line);
  font-size: var(--text-sm);
}

.page-topics .topic-block__links-label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-muted);
}

.page-topics .topic-block__links a {
  color: var(--color-primary);
  text-decoration: none;
  border-bottom: var(--border-thin) solid color-mix(in srgb, var(--color-primary) 42%, transparent);
}

.page-topics .topic-block__links a:hover,
.page-topics .topic-block__links a:focus-visible {
  color: var(--color-accent);
  border-bottom-color: var(--color-accent);
  outline: none;
}

.page-topics .topic-block--warm {
  border-top-color: color-mix(in srgb, var(--color-primary) 34%, transparent);
  background: var(--color-primary-soft);
  border-radius: var(--radius-lg);
  padding: var(--space-4);
}

/* ============ 横向主题带 ============ */
.page-topics .topics-band {
  margin-top: var(--section-y);
  padding: var(--space-6) var(--space-4);
  border-radius: var(--radius-lg);
  background: var(--color-primary-soft);
  color: var(--color-ink);
}

.page-topics .topics-band__head {
  display: grid;
  gap: var(--space-3);
  margin-bottom: var(--space-4);
  padding-bottom: var(--space-4);
  border-bottom: var(--border-thin) solid color-mix(in srgb, var(--color-primary) 30%, transparent);
}

.page-topics .topics-band__eyebrow {
  margin: 0 0 var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.14em;
  color: var(--color-primary);
}

.page-topics .topics-band__title {
  margin: 0;
  font-family: var(--font-heading);
  font-size: var(--text-2xl);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  color: var(--color-ink);
}

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

.page-topics .topics-band__strip {
  display: flex;
  gap: var(--space-2);
  margin: 0 0 var(--space-4);
  padding: 0 0 var(--space-2);
  list-style: none;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: thin;
}

.page-topics .topics-band__chip {
  flex: 0 0 auto;
  scroll-snap-align: start;
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-pill);
  background: var(--color-surface);
  border: var(--border-thin) solid color-mix(in srgb, var(--color-primary) 26%, transparent);
  font-size: var(--text-sm);
  color: var(--color-ink);
  white-space: nowrap;
}

.page-topics .topics-band__chip-no {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-accent);
}

.page-topics .topics-band__media {
  margin: 0;
  border-radius: var(--radius-md);
  overflow: hidden;
  aspect-ratio: 15 / 8;
}

/* 深色主题带 */
.page-topics .topics-band--dark {
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}

.page-topics .topics-band--dark .topics-band__head {
  border-bottom-color: var(--color-contrast-line);
}

.page-topics .topics-band--dark .topics-band__eyebrow {
  color: var(--color-contrast-accent);
}

.page-topics .topics-band--dark .topics-band__title {
  color: var(--color-contrast-ink);
}

.page-topics .topics-band--dark .topics-band__note {
  color: var(--color-contrast-ink);
  opacity: 0.78;
}

.page-topics .topics-band--dark .topics-band__chip {
  background: transparent;
  border-color: var(--color-contrast-line);
  color: var(--color-contrast-ink);
}

.page-topics .topics-band--dark .topics-band__chip-no {
  color: var(--color-contrast-accent);
}

/* ============ 轮换规则 ============ */
.page-topics .topics-cycle {
  padding: var(--section-y-lg) 0 0;
}

.page-topics .topics-cycle__grid {
  display: grid;
  gap: var(--space-6);
}

.page-topics .topics-cycle__eyebrow {
  margin: 0 0 var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.14em;
  color: var(--color-primary);
}

.page-topics .topics-cycle__title {
  margin: 0 0 var(--space-4);
  font-family: var(--font-heading);
  font-size: var(--text-3xl);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
  max-width: 16em;
}

.page-topics .topics-cycle__lede {
  margin: 0 0 var(--space-4);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
  max-width: var(--measure);
}

.page-topics .topics-cycle__rules {
  margin: 0;
  padding: 0;
}

.page-topics .topics-cycle__rule {
  display: grid;
  gap: var(--space-1);
  padding: var(--space-3) 0;
  border-top: var(--border-thin) solid var(--color-line);
}

.page-topics .topics-cycle__rule dt {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  color: var(--color-accent);
}

.page-topics .topics-cycle__rule dd {
  margin: 0;
  font-size: var(--text-sm);
  line-height: var(--leading-body);
  color: var(--color-ink);
}

.page-topics .topics-cycle__media {
  margin: 0;
  border-radius: var(--radius-lg);
  overflow: hidden;
  aspect-ratio: 20 / 13;
  background: var(--color-surface-deep);
}

/* ============ 延伸入口 ============ */
.page-topics .topics-exits {
  padding: var(--section-y) 0;
}

.page-topics .topics-exits__list {
  display: grid;
  gap: var(--space-3);
  margin: var(--space-6) 0 0;
  padding: 0;
  list-style: none;
}

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

.page-topics .topics-exits__link {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  gap: var(--space-2) var(--space-3);
  height: 100%;
  padding: var(--space-3);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-md);
  background: var(--color-surface-alt);
  color: var(--color-ink);
  text-decoration: none;
  transition: border-color 220ms ease, background-color 220ms ease;
}

.page-topics .topics-exits__link:hover,
.page-topics .topics-exits__link:focus-visible {
  border-color: var(--color-accent);
  background: var(--color-primary-soft);
  outline: none;
}

.page-topics .topics-exits__name {
  grid-column: 1;
  grid-row: 1;
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: var(--weight-heading);
  color: var(--color-ink);
}

.page-topics .topics-exits__arrow {
  grid-column: 2;
  grid-row: 1;
  justify-self: end;
  font-family: var(--font-mono);
  font-size: var(--text-lg);
  color: var(--color-accent);
}

.page-topics .topics-exits__desc {
  grid-column: 1 / -1;
  grid-row: 2;
  font-size: var(--text-sm);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
}

/* ============ 响应式 ============ */
@media (min-width: 768px) {
  .page-topics .topics-band {
    padding: var(--space-8) var(--space-6);
  }

  .page-topics .topics-cycle__rule {
    grid-template-columns: 8em minmax(0, 1fr);
    gap: var(--space-4);
    align-items: baseline;
  }

  .page-topics .topics-exits__list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 900px) {
  .page-topics .topics-hero {
    padding: var(--space-8) 0 var(--space-8);
  }

  .page-topics .topics-hero__grid {
    grid-template-columns: minmax(0, 1.3fr) minmax(0, 1fr);
    gap: var(--space-8);
    align-items: start;
  }

  .page-topics .topic-block__body {
    grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
    gap: var(--space-8);
    align-items: start;
  }

  .page-topics .topics-band__head {
    grid-template-columns: minmax(0, 1.2fr) minmax(0, 1fr);
    gap: var(--space-6);
    align-items: end;
  }

  .page-topics .topics-cycle__grid {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr);
    gap: var(--space-8);
    align-items: start;
  }
}

@media (min-width: 1100px) {
  .page-topics .topics-exits__list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (prefers-reduced-motion: no-preference) {
  .page-topics .topics-hero__title {
    animation: topics-title-rise 520ms ease both;
  }

  @keyframes topics-title-rise {
    from {
      opacity: 0;
      transform: translateY(12px);
    }
    to {
      opacity: 1;
      transform: none;
    }
  }
}
<<<END>>>