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

/* ============ 首屏 ============ */
.page-topics .topics-hero {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  padding: var(--space-8) 0 var(--space-6);
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}

.page-topics .topics-hero__bg {
  position: absolute;
  inset: 0;
  z-index: -1;
}

.page-topics .topics-hero__bg img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.42;
}

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

.page-topics .topics-hero__inner {
  position: relative;
}

.page-topics .topics-hero .breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1);
  margin: 0 0 var(--space-4);
  padding: 0;
  list-style: none;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
}

.page-topics .topics-hero .breadcrumb__item {
  color: var(--color-contrast-ink);
}

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

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

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

.page-topics .topics-hero__coord {
  color: var(--color-contrast-accent);
  margin: 0 0 var(--space-2);
}

.page-topics .topics-hero__title {
  margin: 0;
  max-width: 22ch;
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-display);
  line-height: 1.02;
  letter-spacing: -0.012em;
  color: var(--color-surface);
}

.page-topics .topics-hero__lede {
  margin: var(--space-3) 0 0;
  max-width: var(--measure);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-contrast-ink);
}

/* 关键数字 */
.page-topics .topics-stats {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
  margin: var(--space-6) 0 0;
  padding: var(--space-3) 0 0;
  border-top: var(--border-thin) dotted var(--color-contrast-line);
}

.page-topics .topics-stats__cell {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--space-2);
  padding: var(--space-2) 0;
  border-bottom: var(--border-thin) dotted var(--color-contrast-line);
}

.page-topics .topics-stats__label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-contrast-ink);
}

.page-topics .topics-stats__value {
  display: flex;
  align-items: baseline;
  gap: 0.12em;
  margin: 0;
}

.page-topics .topics-stats__num {
  font-family: var(--font-mono);
  font-size: var(--text-figure);
  font-weight: var(--weight-heading);
  line-height: 1;
  color: var(--color-contrast-accent);
  font-variant-numeric: tabular-nums;
}

.page-topics .topics-stats__unit {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  letter-spacing: 0.08em;
  color: var(--color-contrast-ink);
}

/* 横向刻度索引 */
.page-topics .topics-scale-scroll {
  margin-top: var(--space-6);
  overflow-x: auto;
  border-top: var(--border-thin) dotted var(--color-contrast-line);
  border-bottom: var(--border-thin) dotted var(--color-contrast-line);
}

.page-topics .topics-scale {
  display: flex;
  min-width: 100%;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-topics .topics-scale__item {
  flex: 1 1 0;
  min-width: 158px;
  border-left: var(--border-thin) dotted var(--color-contrast-line);
}

.page-topics .topics-scale__item:first-child {
  border-left: 0;
}

.page-topics .topics-scale__node {
  position: relative;
  display: block;
  height: 100%;
  padding: var(--space-3) var(--space-2) var(--space-3);
  text-decoration: none;
  color: var(--color-contrast-ink);
  transition: background-color 200ms ease;
}

.page-topics .topics-scale__tick {
  display: block;
  width: 14px;
  height: var(--border-thin);
  margin-bottom: var(--space-2);
  background: var(--color-contrast-line);
}

.page-topics .topics-scale__code {
  display: block;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
  color: var(--color-contrast-ink);
}

.page-topics .topics-scale__label {
  display: block;
  margin-top: 2px;
  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-surface);
}

.page-topics .topics-scale__meta {
  display: block;
  margin-top: var(--space-1);
  font-size: var(--text-xs);
  line-height: 1.4;
  color: var(--color-contrast-ink);
}

.page-topics .topics-scale__node::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background: var(--color-contrast-accent);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 220ms ease;
}

.page-topics .topics-scale__node:hover,
.page-topics .topics-scale__node:focus-visible {
  background: color-mix(in srgb, var(--color-contrast-accent) 12%, transparent);
}

.page-topics .topics-scale__node:hover::after,
.page-topics .topics-scale__node:focus-visible::after,
.page-topics .topics-scale__node.is-current::after {
  transform: scaleX(1);
}

.page-topics .topics-scale__node.is-current .topics-scale__code {
  color: var(--color-contrast-accent);
}

/* ============ 专题区块外壳 ============ */
.page-topics .topic-zone {
  position: relative;
  padding: var(--section-y) 0;
  border-top: var(--border-thin) dotted var(--color-line);
}

.page-topics .topic-zone--alt {
  background: var(--color-surface-alt);
}

.page-topics .topic-zone--deep {
  background: var(--color-surface-deep);
}

.page-topics .topic-zone__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: var(--space-1) var(--space-3);
  padding-bottom: var(--space-3);
  border-bottom: var(--border-thin) dotted var(--color-line);
}

.page-topics .topic-zone__mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 44px;
  padding: 2px var(--space-1);
  border: var(--border-thin) solid var(--color-primary);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
  color: var(--color-primary);
}

.page-topics .topic-zone__title {
  flex: 1 1 320px;
  margin: 0;
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-2xl);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
}

.page-topics .topic-zone__note {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-muted);
}

.page-topics .topic-zone__grid {
  margin-top: var(--space-6);
}

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

.page-topics .topic-sub__title {
  margin: var(--space-6) 0 var(--space-2);
  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);
}

.page-topics .topic-zone__switch .topic-sub__title {
  margin-top: 0;
}

/* 要点列表 */
.page-topics .topic-points {
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: topic-point;
}

.page-topics .topic-points li {
  position: relative;
  counter-increment: topic-point;
  padding: var(--space-2) 0 var(--space-2) var(--space-6);
  border-top: var(--border-thin) dotted var(--color-line);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink);
}

.page-topics .topic-points li::before {
  content: "[" counter(topic-point, decimal-leading-zero) "]";
  position: absolute;
  left: 0;
  top: var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-accent);
}

/* 表格 */
.page-topics .topic-zone__table {
  margin-top: var(--space-6);
}

.page-topics .index-table caption {
  padding-bottom: var(--space-2);
  text-align: left;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-muted);
}

.page-topics .index-table .cell-code,
.page-topics .index-table .cell-path {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  letter-spacing: 0.06em;
  color: var(--color-ink-muted);
  white-space: nowrap;
}

.page-topics .index-table a {
  color: var(--color-primary);
  text-decoration: none;
  border-bottom: var(--border-thin) dotted var(--color-line);
}

.page-topics .index-table a:hover,
.page-topics .index-table a:focus-visible {
  border-bottom-color: var(--color-primary);
}

/* 图片 */
.page-topics .figure {
  margin: 0;
}

.page-topics .figure__frame {
  display: block;
  padding: var(--space-1);
  border: var(--border-thin) solid var(--color-line);
  background: var(--color-surface-deep);
}

.page-topics .page-topics .figure__frame {
  background: var(--color-surface-deep);
}

.page-topics .figure__frame img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
}

.page-topics .figure__caption {
  margin-top: var(--space-2);
  max-width: var(--measure);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  line-height: 1.5;
  letter-spacing: 0.04em;
  color: var(--color-ink-muted);
}

.page-topics .topic-zone__wide {
  margin-top: var(--space-6);
}

/* ============ 访问路径对比 ============ */
.page-topics .path-compare {
  margin: var(--space-6) 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
  border-top: var(--border-thin) dotted var(--color-line);
}

.page-topics .path-compare__item {
  position: relative;
  padding: var(--space-4) 0 var(--space-4);
  border-bottom: var(--border-thin) dotted var(--color-line);
}

.page-topics .path-compare__item + .path-compare__item {
  padding-left: 0;
}

.page-topics .path-compare__code {
  display: inline-block;
  margin-bottom: var(--space-2);
  padding: 1px var(--space-1);
  border: var(--border-thin) solid var(--color-primary);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
  color: var(--color-primary);
}

.page-topics .path-compare__name {
  margin: 0 0 var(--space-1);
  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-ink);
}

.page-topics .path-compare__who {
  margin: 0 0 var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  color: var(--color-accent);
}

.page-topics .path-compare__how {
  margin: 0 0 var(--space-2);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink);
}

.page-topics .path-compare__back {
  margin: 0;
  padding-top: var(--space-2);
  border-top: var(--border-thin) dotted var(--color-line);
  font-size: var(--text-sm);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
}

/* ============ 查询方法 ============ */
.page-topics .query-scope {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
}

.page-topics .query-scope__item {
  display: flex;
  align-items: baseline;
  gap: var(--space-2);
  padding: var(--space-2) 0;
  border-top: var(--border-thin) dotted var(--color-line);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink);
}

.page-topics .query-scope__code {
  flex: none;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-primary);
}

.page-topics .query-fields {
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: qf;
}

.page-topics .query-field {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 0 var(--space-3);
  padding: var(--space-3) 0;
  border-top: var(--border-thin) dotted var(--color-line);
}

.page-topics .query-field:last-child {
  border-bottom: var(--border-thin) dotted var(--color-line);
}

.page-topics .query-field__code {
  grid-row: 1 / 3;
  align-self: start;
  min-width: 32px;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-ink-muted);
}

.page-topics .query-field__name {
  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);
}

.page-topics .query-field__desc {
  margin-top: var(--space-1);
  font-size: var(--text-sm);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
}

.page-topics .topic-zone__switch {
  margin-top: var(--space-6);
  padding: var(--space-3);
}

.page-topics .topic-zone__switch p {
  margin: var(--space-2) 0 0;
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink);
}

.page-topics .link-arrow {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  letter-spacing: 0.06em;
  color: var(--color-accent);
  text-decoration: none;
  border-bottom: var(--border-thin) dotted var(--color-accent);
}

.page-topics .link-arrow:hover,
.page-topics .link-arrow:focus-visible {
  color: var(--color-focus);
  border-bottom-color: var(--color-focus);
}

/* ============ 订阅边界 ============ */
.page-topics .boundary {
  margin: 0;
}

.page-topics .boundary__row {
  padding: var(--space-3) 0;
  border-top: var(--border-thin) dotted var(--color-line);
}

.page-topics .boundary__row:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-topics .boundary__row dt {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-base);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
}

.page-topics .boundary__row dd {
  margin: var(--space-1) 0 0;
  font-size: var(--text-sm);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
}

.page-topics .boundary__row a {
  color: var(--color-primary);
  text-decoration: none;
  border-bottom: var(--border-thin) dotted var(--color-line);
}

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

/* ============ 相关条目 ============ */
.page-topics .topic-entries {
  margin-top: var(--space-8);
}

.page-topics .topic-entries__title {
  margin: 0 0 var(--space-3);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: var(--weight-body);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-ink-muted);
}

.page-topics .topic-entry {
  border-top: var(--border-thin) dotted var(--color-line);
}

.page-topics .topic-entry:last-child {
  border-bottom: var(--border-thin) dotted var(--color-line);
}

.page-topics .topic-entry__sum {
  display: flex;
  align-items: baseline;
  gap: var(--space-3);
  padding: var(--space-3) 0;
  cursor: pointer;
  list-style: none;
}

.page-topics .topic-entry__sum::-webkit-details-marker {
  display: none;
}

.page-topics .topic-entry__code {
  flex: none;
  min-width: 62px;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-ink-muted);
}

.page-topics .topic-entry__name {
  flex: 1 1 auto;
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-base);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
  border-bottom: var(--border-thin) dotted transparent;
  transition: border-bottom-color 180ms ease;
}

.page-topics .topic-entry__sum::after {
  content: "+";
  flex: none;
  font-family: var(--font-mono);
  font-size: var(--text-base);
  line-height: 1;
  color: var(--color-accent);
}

.page-topics .topic-entry[open] .topic-entry__sum::after {
  content: "−";
}

.page-topics .topic-entry__sum:hover .topic-entry__name,
.page-topics .topic-entry__sum:focus-visible .topic-entry__name {
  border-bottom-color: var(--color-primary);
}

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

/* ============ 延伸关系 ============ */
.page-topics .topics-rel .section-head {
  margin-bottom: var(--space-6);
}

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

.page-topics .relmap__node {
  position: relative;
  padding: var(--space-4) 0 var(--space-4) var(--space-4);
  border-left: var(--border-thin) dotted var(--color-line);
}

.page-topics .relmap__node::before {
  content: "";
  position: absolute;
  left: -4px;
  top: calc(var(--space-4) + 6px);
  width: 7px;
  height: 7px;
  border: var(--border-thin) solid var(--color-primary);
  background: var(--color-surface);
}

.page-topics .relmap__code {
  display: block;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
  color: var(--color-primary);
}

.page-topics .relmap__title {
  margin: var(--space-1) 0 var(--space-2);
  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-ink);
}

.page-topics .relmap__desc {
  margin: 0 0 var(--space-2);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink);
}

.page-topics .relmap__refs {
  margin: 0;
  padding-top: var(--space-2);
  border-top: var(--border-thin) dotted var(--color-line);
  font-size: var(--text-sm);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
}

.page-topics .relmap__refs a {
  color: var(--color-accent);
  text-decoration: none;
  border-bottom: var(--border-thin) dotted var(--color-line);
}

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

.page-topics .topics-rel__note {
  margin-top: var(--space-6);
  padding: var(--space-4);
  border-left: 3px solid var(--color-primary);
}

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

.page-topics .topics-rel__note-line a {
  color: var(--color-contrast-accent);
  text-decoration: none;
  border-bottom: var(--border-thin) dotted var(--color-contrast-line);
}

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

/* ============ 焦点环 ============ */
.page-topics a:focus-visible,
.page-topics summary:focus-visible {
  outline: 2px solid var(--color-focus);
  outline-offset: 2px;
}

.page-topics .topics-hero a:focus-visible,
.page-topics .topics-rel__note a:focus-visible {
  outline-color: var(--color-contrast-accent);
}

/* ============ 响应式 ============ */
@media (min-width: 720px) {
  .page-topics .topics-stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 0 var(--space-4);
  }

  .page-topics .topics-stats__cell {
    display: block;
    border-bottom: 0;
    padding: var(--space-2) 0 0;
  }

  .page-topics .topics-stats__value {
    margin-top: var(--space-1);
  }

  .page-topics .query-scope {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 0 var(--space-4);
  }
}

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

  .page-topics .topic-zone {
    padding: var(--section-y-lg) 0;
  }

  .page-topics .path-compare {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    border-bottom: var(--border-thin) dotted var(--color-line);
  }

  .page-topics .path-compare__item {
    padding: var(--space-4) var(--space-4) var(--space-4) 0;
    border-bottom: 0;
  }

  .page-topics .path-compare__item + .path-compare__item {
    padding-left: var(--space-4);
    border-left: var(--border-thin) dotted var(--color-line);
  }

  .page-topics .relmap {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    border-top: var(--border-thin) dotted var(--color-line);
  }

  .page-topics .relmap::before {
    content: "";
    position: absolute;
    left: 0;
    right: 0;
    top: 0;
    border-top: var(--border-thin) dotted var(--color-line);
  }

  .page-topics .relmap__node {
    padding: var(--space-4) var(--space-3) var(--space-4) 0;
    border-left: 0;
    border-right: var(--border-thin) dotted var(--color-line);
  }

  .page-topics .relmap__node:last-child {
    border-right: 0;
  }

  .page-topics .relmap__node::before {
    left: 0;
    top: -4px;
    background: var(--color-surface);
  }

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

@media (min-width: 1200px) {
  .page-topics .topics-hero__lede {
    font-size: var(--text-lg);
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-topics .topics-scale__node::after,
  .page-topics .topic-entry__name {
    transition: none;
  }
}