/* ===== 专题内容目录 /special/ ===== */
.page-topics {
  --topics-item-no-col: 3.25rem;
  --topics-item-meta-col: 9.5rem;
}

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

.page-topics .topics-hero__shard {
  display: none;
}

.page-topics .topics-hero .container {
  position: relative;
  z-index: 1;
}

.page-topics .topics-hero__title {
  margin: var(--space-3) 0 0;
  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-ink);
  max-width: 20ch;
}

.page-topics .topics-hero__lead {
  margin: var(--space-3) 0 0;
  max-width: 64ch;
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
}

.page-topics .topics-ticks {
  margin-top: var(--space-6);
  height: 18px;
  background-image: linear-gradient(to right, var(--color-line) 0 1px, transparent 1px);
  background-size: calc(100% / 14) 100%;
  background-repeat: repeat-x;
  border-bottom: var(--border-thin) solid var(--color-line);
}

.page-topics .topics-figures {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--space-3) var(--space-2);
  margin: var(--space-4) 0 0;
  padding-top: var(--space-3);
}

.page-topics .topics-figures > div {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding-left: var(--space-2);
  border-left: 2px solid var(--color-primary);
}

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

.page-topics .topics-figures dd {
  margin: 0;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--text-2xl);
  font-weight: var(--weight-heading);
  line-height: 1.12;
  color: var(--color-ink);
  white-space: nowrap;
}

.page-topics .topics-hero__figure {
  margin: var(--space-6) 0 0;
  border-color: var(--color-line);
  background: var(--color-surface-alt);
}

.page-topics .topics-hero__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 1200 / 360;
  object-fit: cover;
}

/* --- 分类导航 --- */
.page-topics .topics-cats-layout {
  display: grid;
  gap: var(--space-4);
  margin-top: var(--space-4);
}

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

.page-topics .topics-cats__link {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 2px var(--space-2);
  align-items: baseline;
  padding: var(--space-2) var(--space-3);
  background: var(--color-surface-alt);
  border: var(--border-thin) solid var(--color-line);
  border-left: 3px solid var(--color-primary);
  border-radius: var(--radius-md);
  text-decoration: none;
  color: inherit;
  transition: background-color 200ms ease, border-color 200ms ease;
}

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

.page-topics .topics-cats__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-cats__count {
  grid-column: 2;
  grid-row: 1;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--text-lg);
  color: var(--color-primary);
}

.page-topics .topics-cats__scope {
  grid-column: 1 / -1;
  font-size: var(--text-sm);
  line-height: 1.6;
  color: var(--color-ink-soft);
}

.page-topics .topics-cats__cycle {
  grid-column: 1 / -1;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.04em;
  color: var(--color-ink-muted);
}

.page-topics .topics-catsfig {
  margin: 0;
  background: var(--color-surface-alt);
}

.page-topics .topics-catsfig img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 720 / 420;
  object-fit: cover;
}

/* --- 条目索引 --- */
.page-topics .topics-index__lead {
  max-width: var(--measure);
  margin: var(--space-3) 0 0;
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
}

.page-topics .topics-index__lead a {
  color: var(--color-primary);
  text-underline-offset: 3px;
}

.page-topics .topics-group {
  margin-top: var(--space-6);
  scroll-margin-top: 96px;
}

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

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

.page-topics .topics-item {
  display: grid;
  grid-template-columns: var(--topics-item-no-col) minmax(0, 1fr);
  grid-template-areas:
    "no body"
    "no meta";
  gap: var(--space-2);
  padding: var(--space-3) var(--space-2);
  border-top: var(--border-thin) solid var(--color-line);
  transition: background-color 200ms ease;
}

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

.page-topics .topics-item:hover,
.page-topics .topics-item:focus-within {
  background: color-mix(in srgb, var(--color-primary-soft) 45%, transparent);
}

.page-topics .topics-item__no {
  grid-area: no;
  padding-top: 3px;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--text-sm);
  letter-spacing: 0.06em;
  color: var(--color-primary);
}

.page-topics .topics-item__body {
  grid-area: body;
  min-width: 0;
}

.page-topics .topics-item__title {
  margin: 0;
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: var(--weight-heading);
  line-height: 1.35;
  color: var(--color-ink);
}

.page-topics .topics-item__note {
  margin: 6px 0 0;
  max-width: 68ch;
  font-size: var(--text-sm);
  line-height: 1.7;
  color: var(--color-ink-soft);
}

.page-topics .topics-item__meta {
  grid-area: meta;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-1);
}

/* --- 移动端入口 --- */
.page-topics .topics-mobile {
  display: grid;
  gap: var(--space-4);
  align-items: start;
}

.page-topics .topics-mobile__figure {
  margin: 0;
  max-width: 24rem;
  background: var(--color-surface-alt);
}

.page-topics .topics-mobile__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 480 / 640;
  object-fit: cover;
}

.page-topics .topics-mobile__text p {
  margin: var(--space-3) 0 0;
  max-width: 62ch;
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
}

.page-topics .topics-mobile__text a {
  color: var(--color-primary);
  text-underline-offset: 3px;
}

/* --- 更新批次 --- */
.page-topics .topics-batch {
  display: grid;
  gap: var(--space-4);
  align-items: start;
  padding: var(--space-4) var(--space-3);
}

.page-topics .topics-batch .sec-num {
  color: var(--color-contrast-accent);
}

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

.page-topics .topics-batch__text p {
  margin: var(--space-3) 0 0;
  max-width: 62ch;
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-contrast-ink);
}

.page-topics .topics-batch__text a {
  color: var(--color-contrast-accent);
  text-underline-offset: 3px;
}

.page-topics .topics-batch__figure {
  margin: 0;
  background: var(--color-contrast-surface);
  border-color: var(--color-contrast-line);
}

.page-topics .topics-batch__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 800 / 320;
  object-fit: cover;
}

/* --- 专题与教程的衔接 --- */
.page-topics .topics-bridge {
  display: grid;
  gap: var(--space-4);
  margin-top: var(--space-4);
  align-items: start;
}

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

.page-topics .topics-bridge__list li {
  display: grid;
  grid-template-columns: 2rem minmax(0, 1fr);
  gap: var(--space-2);
  padding-top: var(--space-2);
  border-top: var(--border-thin) solid var(--color-line);
}

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

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

.page-topics .topics-bridge__figure {
  margin: 0;
  background: var(--color-surface-alt);
}

.page-topics .topics-bridge__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 640 / 360;
  object-fit: cover;
}

.page-topics .topics-bridge__foot {
  margin: var(--space-4) 0 0;
  padding-top: var(--space-3);
  border-top: var(--border-thin) solid var(--color-line);
  font-size: var(--text-sm);
  line-height: 1.7;
  color: var(--color-ink-soft);
}

.page-topics .topics-bridge__foot a {
  color: var(--color-primary);
  text-underline-offset: 3px;
}

/* --- 断点：平板 --- */
@media (min-width: 720px) {
  .page-topics .topics-hero {
    padding: var(--space-8) 0 var(--space-8);
  }

  .page-topics .topics-hero__shard {
    display: block;
    position: absolute;
    inset: auto -8% 22% auto;
    width: min(56%, 640px);
    height: min(58%, 340px);
    background: var(--color-primary-soft);
    clip-path: polygon(26% 0, 100% 8%, 92% 100%, 0 82%);
    pointer-events: none;
    z-index: 0;
  }

  .page-topics .topics-figures {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: var(--space-3);
  }

  .page-topics .topics-mobile {
    grid-template-columns: minmax(0, 4fr) minmax(0, 8fr);
    gap: var(--space-6);
  }

  .page-topics .topics-mobile__figure {
    max-width: none;
  }

  .page-topics .topics-mobile .sec-head {
    margin-top: 0;
  }

  .page-topics .topics-batch {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: var(--space-6);
    padding: var(--space-6) var(--space-4);
  }

  .page-topics .topics-bridge {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: var(--space-6);
  }
}

/* --- 断点：桌面 --- */
@media (min-width: 900px) {
  .page-topics .topics-cats-layout {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: var(--space-6);
    align-items: start;
  }
}

@media (min-width: 1024px) {
  .page-topics .topics-item {
    grid-template-columns: var(--topics-item-no-col) minmax(0, 1fr) var(--topics-item-meta-col);
    grid-template-areas: "no .page-topics meta";
    align-items: start;
    gap: var(--space-3);
  }

  .page-topics .topics-item__meta {
    flex-direction: column;
    align-items: flex-start;
    gap: 6px;
  }
}

/* --- 大标题与窄屏收口 --- */
@media (max-width: 599px) {
  .page-topics .topics-hero {
    padding: var(--space-6) 0 var(--space-4);
  }

  .page-topics .topics-ticks {
    margin-top: var(--space-4);
  }

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

  .page-topics .topics-item {
    grid-template-columns: 2.5rem minmax(0, 1fr);
    padding: var(--space-3) var(--space-1);
  }

  .page-topics .topics-batch {
    padding: var(--space-3) var(--space-2);
  }
}

/* --- 减少动效 --- */
@media (prefers-reduced-motion: reduce) {
  .page-topics .topics-cats__link,
  .page-topics .topics-item {
    transition: none;
  }
}
</main>