.page-topics {
  background: var(--color-surface);
  color: var(--color-ink);
  font-family: var(--font-body);
  line-height: var(--leading-body);
}

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

/* ---------- 首屏编号刻度带 ---------- */

.page-topics .page-topics-hero {
  position: relative;
  overflow: hidden;
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  padding-block: calc(var(--space-8) + var(--space-4)) var(--space-6);
}

.page-topics .page-topics-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image: repeating-linear-gradient(
    90deg,
    transparent 0,
    transparent 79px,
    color-mix(in srgb, var(--color-contrast-line) 70%, transparent) 79px,
    color-mix(in srgb, var(--color-contrast-line) 70%, transparent) 80px
  );
  opacity: 0.45;
}

.page-topics .page-topics-hero__grid {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--space-4);
}

.page-topics .page-topics-scale {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1) var(--space-3);
  margin: 0;
  padding-left: var(--space-3);
  list-style: none;
  border-left: var(--border-thick) solid var(--color-primary);
}

.page-topics .page-topics-scale__item {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  letter-spacing: 0.08em;
  color: color-mix(in srgb, var(--color-contrast-ink) 58%, transparent);
}

.page-topics .page-topics-hero__title {
  margin: var(--space-2) 0 var(--space-3);
  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);
}

.page-topics .page-topics-hero__lede {
  margin: 0;
  max-width: var(--measure);
  font-size: var(--text-lg);
  color: color-mix(in srgb, var(--color-contrast-ink) 88%, transparent);
}

.page-topics .page-topics-hero__figures {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--space-3);
  margin: var(--space-6) 0 0;
  padding-top: var(--space-4);
  border-top: var(--border-thin) solid var(--color-contrast-line);
}

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

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

.page-topics .page-topics-figure__val {
  margin: var(--space-1) 0 0;
  font-family: var(--font-mono);
  font-size: var(--text-figure);
  line-height: 1;
  color: var(--color-contrast-accent);
}

.page-topics .page-topics-figure__val--word {
  font-size: var(--text-2xl);
  line-height: var(--leading-heading);
  padding-block: var(--space-1);
}

.page-topics .page-topics-hero__media {
  margin-block: var(--space-6);
}

.page-topics .media-frame img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: var(--radius-sm);
}

.page-topics .page-topics-caption {
  margin-top: var(--space-2);
  padding-left: var(--space-2);
  border-left: var(--border-thick) solid var(--color-primary);
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
}

.page-topics .page-topics-caption--dark {
  color: color-mix(in srgb, var(--color-contrast-ink) 74%, transparent);
  border-left-color: var(--color-contrast-accent);
}

/* ---------- 章节目录条 ---------- */

.page-topics .page-topics-toc {
  position: sticky;
  top: 0;
  z-index: 6;
  margin-top: var(--space-4);
  background: var(--color-surface);
  border-top: var(--border-thin) solid var(--color-line);
  border-bottom: var(--border-thick) solid var(--color-line);
}

.page-topics .page-topics-toc__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: var(--space-1) var(--space-4);
  padding-block: var(--space-2);
}

.page-topics .page-topics-toc__list {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1) var(--space-3);
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-topics .page-topics-toc__list a {
  display: inline-block;
  padding-block: var(--space-1);
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
  text-decoration: none;
  border-bottom: var(--border-thick) solid transparent;
}

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

/* ---------- 分类导航 ---------- */

.page-topics .page-topics-cats {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: var(--border-thick) solid var(--color-line);
}

.page-topics .page-topics-cat {
  padding: var(--space-4) 0;
  border-bottom: var(--border-thin) solid var(--color-line);
}

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

.page-topics .page-topics-cat__name {
  margin: var(--space-1) 0 var(--space-2);
  font-family: var(--font-heading);
  font-size: var(--text-xl);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
}

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

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

.page-topics .page-topics-cat__note {
  margin: 0;
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
}

.page-topics .page-topics-catband__media {
  margin: var(--space-6) 0 0;
}

/* ---------- 编号目录 ---------- */

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

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

.page-topics .page-topics-group__head {
  position: relative;
  padding-top: var(--space-2);
  border-top: var(--border-thick) solid var(--color-primary);
}

.page-topics .page-topics-group__head::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: calc(var(--border-thick) + var(--border-thin) * 2);
  height: var(--border-thin);
  background: var(--color-primary);
}

.page-topics .page-topics-group__no {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  letter-spacing: 0.1em;
  color: var(--color-accent);
}

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

.page-topics .page-topics-group__note {
  margin: 0 0 var(--space-3);
  max-width: var(--measure);
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
}

.page-topics .page-topics-entries {
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-topics .page-topics-entry {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--space-2);
  padding-block: var(--space-4);
  border-bottom: var(--border-thin) solid var(--color-line);
}

.page-topics .page-topics-entry__no {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--text-2xl);
  line-height: 1;
  color: var(--color-primary);
}

.page-topics .page-topics-entry__title {
  margin: 0 0 var(--space-1);
  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);
}

.page-topics .page-topics-entry__desc {
  margin: 0;
  max-width: 62ch;
  font-size: var(--text-base);
  color: var(--color-ink-soft);
}

.page-topics .page-topics-entry__meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2);
  margin: 0;
}

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

.page-topics .page-topics-entry:hover .page-topics-entry__title {
  color: var(--color-primary);
}

/* ---------- 一期结构（深墨段） ---------- */

.page-topics .page-topics-issue {
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}

.page-topics .page-topics-issue .section-head__title {
  color: var(--color-contrast-ink);
}

.page-topics .page-topics-issue .section-head__note {
  color: color-mix(in srgb, var(--color-contrast-ink) 72%, transparent);
}

.page-topics .page-topics-issue__cols {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--space-4);
}

.page-topics .page-topics-issue__col {
  padding-top: var(--space-3);
  border-top: var(--border-thick) solid var(--color-contrast-accent);
}

.page-topics .page-topics-issue__col-no {
  margin: 0;
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  color: var(--color-contrast-accent);
}

.page-topics .page-topics-issue__col-title {
  margin: var(--space-1) 0 var(--space-2);
  font-family: var(--font-heading);
  font-size: var(--text-xl);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
}

.page-topics .page-topics-issue__col-text {
  margin: 0;
  font-size: var(--text-base);
  color: color-mix(in srgb, var(--color-contrast-ink) 82%, transparent);
}

.page-topics .page-topics-issue__link {
  margin: var(--space-6) 0 0;
  max-width: var(--measure);
  font-size: var(--text-base);
  color: color-mix(in srgb, var(--color-contrast-ink) 82%, transparent);
}

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

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

.page-topics .page-topics-issue__media {
  margin: var(--space-6) 0 0;
}

/* ---------- 更新与归档 ---------- */

.page-topics .page-topics-archive__points {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--space-2);
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: var(--border-thick) solid var(--color-line);
}

.page-topics .page-topics-archive__points li {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--space-1);
  padding-block: var(--space-3);
  border-bottom: var(--border-thin) solid var(--color-line);
}

.page-topics .page-topics-archive__key {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  letter-spacing: 0.12em;
  color: var(--color-accent);
}

.page-topics .page-topics-archive__val {
  font-size: var(--text-base);
  color: var(--color-ink);
}

.page-topics .page-topics-archive__media {
  margin: var(--space-6) 0 0;
}

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

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

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

/* ---------- 下一条阅读路径 ---------- */

.page-topics .page-topics-next__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--space-3);
}

.page-topics .page-topics-next__item {
  display: block;
  padding: var(--space-4);
  border: var(--border-thin) solid var(--color-line);
  border-top: var(--border-thick) solid var(--color-primary);
  border-radius: var(--radius-md);
  background: var(--color-surface-alt);
  color: inherit;
  text-decoration: none;
  transition: background-color 0.2s ease;
}

.page-topics .page-topics-next__item:hover,
.page-topics .page-topics-next__item:focus-visible {
  background: var(--color-highlight);
}

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

.page-topics .page-topics-next__title {
  margin: var(--space-1) 0 var(--space-2);
  font-family: var(--font-heading);
  font-size: var(--text-xl);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
}

.page-topics .page-topics-next__text {
  margin: 0 0 var(--space-3);
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
}

.page-topics .page-topics-next__go {
  display: inline-block;
  padding-bottom: var(--border-thin);
  font-size: var(--text-sm);
  letter-spacing: 0.06em;
  color: var(--color-accent);
  border-bottom: var(--border-thin) solid var(--color-accent);
}

.page-topics .page-topics-next__media {
  margin: var(--space-6) 0 0;
}

/* ---------- 响应式 ---------- */

@media (min-width: 640px) {
  .page-topics .page-topics-hero__figures {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: var(--space-4);
  }

  .page-topics .page-topics-archive__points li {
    grid-template-columns: 96px minmax(0, 1fr);
    gap: var(--space-3);
    align-items: baseline;
  }
}

@media (min-width: 700px) {
  .page-topics .page-topics-cats {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }

  .page-topics .page-topics-cat {
    padding: var(--space-4) var(--space-3);
    border-bottom: none;
    border-right: var(--border-thin) solid var(--color-line);
  }

  .page-topics .page-topics-cat:first-child {
    padding-left: 0;
  }

  .page-topics .page-topics-cat:last-child {
    padding-right: 0;
    border-right: none;
  }
}

@media (min-width: 720px) {
  .page-topics .page-topics-entry {
    grid-template-columns: 84px minmax(0, 1fr) 172px;
    gap: var(--space-4);
    align-items: start;
  }

  .page-topics .page-topics-entry__meta {
    flex-direction: column;
    align-items: flex-end;
    justify-content: flex-start;
    gap: var(--space-1);
    text-align: right;
  }
}

@media (min-width: 780px) {
  .page-topics .page-topics-issue__cols {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: var(--space-6);
  }

  .page-topics .page-topics-next__grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 860px) {
  .page-topics .page-topics-hero {
    padding-block: calc(var(--space-8) + var(--space-8)) var(--space-8);
  }

  .page-topics .page-topics-hero__grid {
    grid-template-columns: 96px minmax(0, 1fr);
    gap: var(--space-8);
    align-items: start;
  }

  .page-topics .page-topics-scale {
    flex-direction: column;
    flex-wrap: nowrap;
    gap: 0;
    padding: var(--space-2) 0 var(--space-2) var(--space-3);
    transform: rotate(-1.4deg);
    transform-origin: left top;
  }

  .page-topics .page-topics-scale__item {
    position: relative;
    padding-block: calc(var(--space-1) * 0.75);
  }

  .page-topics .page-topics-scale__item::before {
    content: "";
    position: absolute;
    left: calc(var(--space-3) * -1);
    top: 50%;
    width: var(--space-2);
    height: var(--border-thin);
    background: var(--color-primary);
  }

  .page-topics .page-topics-hero__media {
    margin-top: var(--space-8);
  }
}
<<<END>>>