.page-topics {
  --topics-bleed: clamp(32px, 9vw, 170px);
  --topics-hero-top: clamp(104px, 15vw, 184px);
  --topics-rule: var(--color-accent);
  background: var(--color-surface);
  color: var(--color-ink);
  overflow-x: clip;
}

/* ---------- 首屏 ---------- */
.page-topics .topics-hero {
  position: relative;
  overflow: hidden;
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  padding-bottom: var(--space-6);
}

.page-topics .topics-hero__bg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: 72% 38%;
  opacity: 0.55;
}

.page-topics .topics-hero__scrim {
  position: absolute;
  inset: 0;
  background: var(--overlay-scrim);
}

.page-topics .topics-hero__body {
  position: relative;
  z-index: 2;
  padding-top: var(--topics-hero-top);
  padding-bottom: var(--space-6);
}

.page-topics .topics-hero__crumb {
  color: var(--color-contrast-ink);
  opacity: 0.72;
  margin-bottom: var(--space-6);
}

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

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

.page-topics .topics-hero__eyebrow {
  color: var(--color-contrast-accent);
  margin: 0 0 var(--space-3);
}

.page-topics .topics-hero__title {
  font-family: var(--font-heading);
  font-size: var(--text-display);
  font-weight: var(--weight-heading);
  line-height: 0.9;
  letter-spacing: var(--tracking-heading);
  color: var(--color-contrast-ink);
  margin: 0 0 var(--space-4);
}

.page-topics .topics-hero__lede {
  max-width: 48ch;
  color: var(--color-contrast-ink);
  opacity: 0.86;
  margin: 0;
}

.page-topics .topics-figures {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  gap: var(--space-4) var(--space-6);
  margin: var(--space-8) 0 0;
  padding-top: var(--space-3);
  border-top: var(--border-thin) solid var(--color-contrast-line);
}

.page-topics .topics-figure {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.page-topics .topics-figure dt {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--color-contrast-ink);
  opacity: 0.62;
}

.page-topics .topics-figure dd {
  margin: 0;
}

.page-topics .topics-hero .figure {
  color: var(--color-contrast-ink);
  line-height: 0.86;
}

.page-topics .topics-figure--lead .figure {
  color: var(--color-contrast-accent);
}

/* 六组标签色块条——横向溢出容器右边界 */
.page-topics .topics-hero__rail {
  position: relative;
  z-index: 2;
  display: flex;
  flex-wrap: nowrap;
  gap: var(--space-2);
  list-style: none;
  margin: 0;
  padding: 0 var(--space-2) var(--space-2) max(var(--gutter), calc((100vw - var(--container)) / 2 + var(--gutter)));
  width: 100%;
  overflow-x: auto;
  scrollbar-width: none;
}

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

.page-topics .topics-chip {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: baseline;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-4);
  background: var(--color-primary);
  color: var(--color-primary-ink);
  text-decoration: none;
  border-radius: var(--radius-sm);
}

.page-topics .topics-chip--rule {
  background: var(--color-accent);
  color: var(--color-accent-ink);
}

.page-topics .topics-chip__idx {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.14em;
  opacity: 0.78;
}

.page-topics .topics-chip__name {
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: var(--weight-heading);
  letter-spacing: -0.015em;
  white-space: nowrap;
}

.page-topics .topics-chip__n {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  opacity: 0.78;
  white-space: nowrap;
}

.page-topics .topics-chip:hover,
.page-topics .topics-chip:focus-visible {
  outline: var(--border-thick) solid var(--color-focus);
  outline-offset: 2px;
}

/* ---------- 章节节奏 ---------- */
.page-topics .topics-section {
  padding-block: var(--section-y);
}

.page-topics .topics-section--lg {
  padding-block: var(--section-y-lg);
}

.page-topics .topics-section h2 {
  font-family: var(--font-heading);
  font-size: var(--text-xl);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  margin: var(--space-2) 0 var(--space-3);
}

/* ---------- 六组归口 ---------- */
.page-topics .topics-groups {
  background: var(--color-surface);
}

.page-topics .topics-groups__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-6);
}

.page-topics .topics-groups__intro p {
  max-width: var(--measure);
  color: var(--color-ink-soft);
  margin: 0 0 var(--space-3);
}

.page-topics .topics-groups__media {
  margin: var(--space-6) 0 0;
  max-width: 420px;
}

.page-topics .topics-groups__media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 1 / 1;
  object-fit: cover;
  background: var(--color-surface-deep);
}

.page-topics .topics-groups__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-2);
  counter-reset: none;
}

.page-topics .topics-group {
  padding: var(--space-3);
  background: var(--color-surface-alt);
  border-top: var(--border-thick) solid var(--color-primary);
}

.page-topics .topics-group:nth-child(4),
.page-topics .topics-group:nth-child(5),
.page-topics .topics-group:nth-child(6) {
  border-top-color: var(--topics-rule);
}

.page-topics .topics-group__head {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin-bottom: var(--space-2);
}

.page-topics .topics-group__code {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  letter-spacing: 0.14em;
  color: var(--color-ink-muted);
}

.page-topics .topics-group h3 {
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: var(--weight-heading);
  line-height: 1.24;
  letter-spacing: var(--tracking-heading);
  margin: 0 0 var(--space-2);
}

.page-topics .topics-group p {
  margin: 0 0 var(--space-2);
  color: var(--color-ink-soft);
}

.page-topics .topics-group__note {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-ink-muted);
  margin: 0;
}

/* ---------- 十四个专题速查 ---------- */
.page-topics .topics-index {
  background: var(--color-surface-alt);
}

.page-topics .topics-index__note {
  max-width: var(--measure);
  color: var(--color-ink-soft);
  margin: 0 0 var(--space-6);
}

.page-topics .topics-index__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
}

.page-topics .topics-index__row a {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: var(--space-1) var(--space-3);
  padding: var(--space-2) var(--space-2) var(--space-2) 0;
  text-decoration: none;
  color: var(--color-ink);
  border-bottom: var(--border-thin) solid var(--color-line);
}

.page-topics .topics-index__row a:hover,
.page-topics .topics-index__row a:focus-visible {
  background: var(--color-primary-soft);
}

.page-topics .topics-index__no {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  letter-spacing: 0.1em;
  color: var(--color-primary);
}

.page-topics .topics-index__no--rule {
  color: var(--topics-rule);
}

.page-topics .topics-index__name {
  flex: 1 1 auto;
  min-width: 0;
  font-family: var(--font-heading);
  font-size: var(--text-base);
  font-weight: var(--weight-heading);
  letter-spacing: -0.01em;
}

.page-topics .topics-index__state {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-ink-muted);
  white-space: nowrap;
}

.page-topics .topics-index__tip {
  grid-column: 1 / -1;
  margin: var(--space-2) 0;
  padding: var(--space-3) var(--space-3);
  background: var(--color-highlight);
  color: var(--color-ink);
}

.page-topics .topics-index__tip p {
  margin: 0;
  font-size: var(--text-sm);
  line-height: var(--leading-body);
}

.page-topics .topics-index__tipkey {
  display: inline-block;
  margin-right: var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--color-accent);
}

/* ---------- 服务类卡片流 ---------- */
.page-topics .topics-service {
  background: var(--color-surface);
  overflow: hidden;
}

.page-topics .topics-service__head {
  max-width: var(--measure);
  margin-bottom: var(--space-8);
}

.page-topics .topics-service__head p {
  color: var(--color-ink-soft);
  margin: 0;
}

.page-topics .topics-service__flow {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-3);
}

.page-topics .topic-card {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  padding: var(--space-4);
  background: var(--color-primary-soft);
  border-top: var(--border-thick) solid var(--color-primary);
}

.page-topics .topic-card__no {
  font-family: var(--font-mono);
  font-size: var(--text-2xl);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--color-primary);
}

.page-topics .topic-card h3 {
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: var(--weight-heading);
  line-height: 1.24;
  letter-spacing: var(--tracking-heading);
  margin: 0;
}

.page-topics .topic-card > p {
  margin: 0;
  color: var(--color-ink-soft);
}

.page-topics .topic-card__meta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1) var(--space-4);
  margin: var(--space-2) 0 0;
  padding-top: var(--space-2);
  border-top: var(--border-thin) solid color-mix(in srgb, var(--color-primary) 34%, transparent);
}

.page-topics .topic-card__pair {
  display: flex;
  align-items: baseline;
  gap: var(--space-1);
}

.page-topics .topic-card__pair dt {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-ink-muted);
}

.page-topics .topic-card__pair dd {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  color: var(--color-ink);
  white-space: nowrap;
}

.page-topics .topic-card__link {
  align-self: flex-start;
  margin-top: auto;
  padding-top: var(--space-3);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-ink);
  text-decoration: none;
  border-bottom: var(--border-thick) solid var(--color-primary);
}

.page-topics .topic-card__link:hover,
.page-topics .topic-card__link:focus-visible {
  color: var(--color-accent);
  border-bottom-color: var(--color-accent);
}

/* ---------- 规则类编号表格 ---------- */
.page-topics .topics-rule {
  background: var(--color-surface-alt);
}

.page-topics .topics-rule__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-6);
}

.page-topics .topics-rule__head {
  max-width: var(--measure);
  margin-bottom: var(--space-4);
}

.page-topics .topics-rule__head p {
  color: var(--color-ink-soft);
  margin: 0;
}

.page-topics .topics-rule__scroll {
  overflow-x: auto;
}

.page-topics .topics-table {
  width: 100%;
  min-width: 720px;
  border-collapse: collapse;
  font-size: var(--text-sm);
  text-align: left;
}

.page-topics .topics-table caption {
  text-align: left;
  padding-bottom: var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-ink-muted);
}

.page-topics .topics-table thead th {
  padding: var(--space-2) var(--space-2) var(--space-2) 0;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: var(--weight-body);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--color-ink-muted);
  border-bottom: var(--border-thick) solid var(--color-ink);
}

.page-topics .topics-table tbody th,
.page-topics .topics-table tbody td {
  padding: var(--space-3) var(--space-2) var(--space-3) 0;
  border-bottom: var(--border-thin) solid var(--color-line);
  vertical-align: top;
}

.page-topics .topics-table__no {
  font-family: var(--font-mono);
  font-size: var(--text-base);
  font-weight: var(--weight-heading);
  letter-spacing: 0.06em;
  color: var(--topics-rule);
  white-space: nowrap;
}

.page-topics .topics-table__name {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  min-width: 20ch;
}

.page-topics .topics-table__title {
  font-family: var(--font-heading);
  font-size: var(--text-base);
  font-weight: var(--weight-heading);
  letter-spacing: -0.01em;
  color: var(--color-ink);
}

.page-topics .topics-table__desc {
  color: var(--color-ink-muted);
  font-size: var(--text-sm);
  line-height: 1.6;
}

.page-topics .topics-table__num {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  color: var(--color-ink);
  white-space: nowrap;
}

.page-topics .topics-table__link {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-ink);
  text-decoration: none;
  border-bottom: var(--border-thick) solid var(--topics-rule);
  white-space: nowrap;
}

.page-topics .topics-table__link:hover,
.page-topics .topics-table__link:focus-visible {
  color: var(--color-accent);
}

.page-topics .topics-rule__aside {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.page-topics .topics-rule__media {
  margin: 0;
  overflow: hidden;
  background: var(--color-surface-deep);
}

.page-topics .topics-rule__media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 4;
  object-fit: cover;
}

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

/* ---------- 对照与固定路径 ---------- */
.page-topics .topics-export {
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}

.page-topics .topics-export__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-6);
}

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

.page-topics .topics-export__body h2 {
  color: var(--color-contrast-ink);
}

.page-topics .topics-export__body > p {
  max-width: var(--measure);
  color: var(--color-contrast-ink);
  opacity: 0.84;
  margin: 0 0 var(--space-4);
}

.page-topics .topics-export__list {
  list-style: none;
  margin: 0 0 var(--space-6);
  padding: 0;
  border-top: var(--border-thin) solid var(--color-contrast-line);
}

.page-topics .topics-export__list li {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  align-items: baseline;
  padding: var(--space-2) 0;
  border-bottom: var(--border-thin) solid var(--color-contrast-line);
  font-size: var(--text-sm);
  color: var(--color-contrast-ink);
}

.page-topics .topics-export__k {
  flex: 0 0 auto;
  min-width: 6em;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-contrast-accent);
}

.page-topics .topics-export__actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-3) var(--space-4);
}

.page-topics .topics-export__back {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  letter-spacing: 0.1em;
  color: var(--color-contrast-ink);
  text-decoration: none;
  border-bottom: var(--border-thick) solid var(--color-contrast-accent);
}

.page-topics .topics-export__back:hover,
.page-topics .topics-export__back:focus-visible {
  color: var(--color-contrast-accent);
}

.page-topics .topics-export__media {
  margin: 0;
  overflow: hidden;
  background: var(--color-contrast-line);
}

.page-topics .topics-export__media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 1;
  object-fit: cover;
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-topics .topics-groups__list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-topics .topics-index__list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: var(--space-6);
  }
}

@media (min-width: 900px) {
  .page-topics .topics-groups__grid {
    grid-template-columns: minmax(0, 4fr) minmax(0, 7fr);
    gap: var(--space-8);
    align-items: start;
  }

  .page-topics .topics-groups__media {
    margin-top: var(--space-8);
  }

  .page-topics .topics-service__flow {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    margin-right: calc(-1 * var(--space-4));
  }

  .page-topics .topics-service__flow > .topic-card:nth-child(even) {
    margin-top: var(--space-8);
  }

  .page-topics .topics-export__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: var(--space-8);
    align-items: center;
  }

  .page-topics .topics-export__media img {
    aspect-ratio: 4 / 3;
  }
}

@media (min-width: 1000px) {
  .page-topics .topics-rule__grid {
    grid-template-columns: minmax(0, 8fr) minmax(0, 3fr);
    gap: var(--space-8);
    align-items: start;
  }
}

@media (min-width: 1080px) {
  .page-topics .topics-hero__rail {
    width: calc(100% + var(--topics-bleed));
    overflow-x: visible;
  }

  .page-topics .topics-service__flow {
    margin-right: calc(-1 * var(--space-8));
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-topics [data-reveal] {
    transform: none !important;
    transition: none !important;
  }
}