.page-topics {
  --tp-pad-y: clamp(64px, 9vw, var(--section-y));
  --tp-card-w: min(76vw, 302px);
  --tp-rail-gap: var(--space-3);
  display: block;
  background: var(--color-surface);
  color: var(--color-ink);
}

/* ---------- 首屏 ---------- */

.page-topics .topics-hero {
  position: relative;
  overflow: hidden;
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  padding-block: calc(var(--tp-pad-y) * 1.1) var(--tp-pad-y);
  isolation: isolate;
}

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

.page-topics .topics-hero__bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.34;
}

.page-topics .topics-hero__bg::after {
  content: "";
  position: absolute;
  inset: 0;
  background: var(--overlay-scrim);
}

.page-topics .topics-hero__cut {
  position: absolute;
  z-index: 0;
  top: -18%;
  right: -14%;
  width: 66%;
  height: 140%;
  transform: rotate(-11deg);
  background: linear-gradient(
    155deg,
    color-mix(in srgb, var(--color-accent) 55%, transparent) 0%,
    color-mix(in srgb, var(--color-primary) 42%, transparent) 52%,
    transparent 100%
  );
  pointer-events: none;
}

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

.page-topics .topics-hero__crumbs .crumbs {
  margin: 0 0 var(--space-4);
}

.page-topics .topics-hero__crumbs .crumbs a,
.page-topics .topics-hero__crumbs .crumbs span {
  color: color-mix(in srgb, var(--color-contrast-ink) 72%, transparent);
}

.page-topics .topics-hero__crumbs .crumbs a:hover {
  color: var(--color-contrast-ink);
}

.page-topics .topics-hero__marker {
  color: color-mix(in srgb, var(--color-contrast-ink) 68%, transparent);
  margin-bottom: var(--space-3);
}

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

.page-topics .topics-hero__title {
  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);
  margin: 0 0 var(--space-3);
  max-width: 16ch;
  color: var(--color-contrast-ink);
  text-wrap: balance;
}

.page-topics .topics-hero__lede {
  margin: 0;
  max-width: 56ch;
  font-size: var(--text-lg);
  line-height: 1.62;
  color: color-mix(in srgb, var(--color-contrast-ink) 82%, transparent);
}

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

.page-topics .topics-hero__stats .figure {
  display: flex;
  flex-direction: column-reverse;
  gap: 4px;
}

.page-topics .topics-hero__stats .figure__value {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--text-2xl);
  font-weight: var(--weight-heading);
  line-height: 1;
  color: var(--color-contrast-accent);
}

.page-topics .topics-hero__stats .figure__label {
  font-size: var(--text-sm);
  color: color-mix(in srgb, var(--color-contrast-ink) 68%, transparent);
}

/* 索引墙 */

.page-topics .topics-index {
  position: relative;
  z-index: 1;
  margin-top: var(--space-8);
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-2);
}

.page-topics .topics-index__item {
  display: grid;
  grid-template-columns: auto 1fr;
  grid-template-areas:
    "num name"
    "num desc";
  column-gap: var(--space-2);
  row-gap: 4px;
  align-items: start;
  padding: var(--space-3);
  border-radius: var(--radius-lg);
  border: var(--border-thin) solid color-mix(in srgb, var(--color-contrast-ink) 16%, transparent);
  background: color-mix(in srgb, var(--color-contrast-surface) 72%, transparent);
  color: var(--color-contrast-ink);
  text-decoration: none;
  transition: transform 0.22s ease, border-color 0.22s ease, box-shadow 0.22s ease;
}

.page-topics .topics-index__item:hover,
.page-topics .topics-index__item:focus-visible {
  transform: translateY(-4px);
  border-color: color-mix(in srgb, var(--color-contrast-accent) 62%, transparent);
  box-shadow: var(--shadow-2);
}

.page-topics .topics-index__num {
  grid-area: num;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--text-sm);
  color: var(--color-contrast-accent);
  padding-top: 3px;
}

.page-topics .topics-index__name {
  grid-area: name;
  font-family: var(--font-heading);
  font-size: var(--text-xl);
  font-weight: var(--weight-heading);
  line-height: 1.24;
  letter-spacing: var(--tracking-heading);
}

.page-topics .topics-index__desc {
  grid-area: desc;
  font-size: var(--text-sm);
  line-height: 1.66;
  color: color-mix(in srgb, var(--color-contrast-ink) 72%, transparent);
}

.page-topics .topics-hero__scale {
  position: absolute;
  z-index: 1;
  left: 50%;
  bottom: var(--space-3);
  transform: translateX(-50%);
  display: flex;
  align-items: flex-end;
  gap: 6px;
  opacity: 0.4;
  pointer-events: none;
}

.page-topics .topics-hero__scale i {
  display: block;
  width: 1px;
  height: 14px;
  background: var(--color-contrast-ink);
}

.page-topics .topics-hero__scale i:nth-child(4n + 1) {
  height: 24px;
}

/* ---------- 主线区块 ---------- */

.page-topics .topics-lane {
  padding-block: var(--tp-pad-y);
  background: var(--color-surface);
}

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

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

.page-topics .topics-lane__head {
  align-self: start;
}

.page-topics .topics-lane__head > .marker {
  margin: 0 0 var(--space-3);
}

.page-topics .topics-lane__title {
  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);
  margin: 0 0 var(--space-2);
  color: var(--color-ink);
  text-wrap: balance;
}

.page-topics .topics-lane__lede {
  margin: 0 0 var(--space-4);
  max-width: 46ch;
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
}

.page-topics .topics-lane__cta {
  text-decoration: none;
}

.page-topics .topics-lane__body {
  min-width: 0;
  display: grid;
  gap: var(--space-4);
}

.page-topics .topics-lane__media {
  overflow: hidden;
}

.page-topics .topics-lane__media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 10;
  object-fit: cover;
}

/* 横向滚动带 */

.page-topics .topics-rail {
  display: flex;
  gap: var(--tp-rail-gap);
  margin: 0;
  padding: 4px 4px var(--space-3);
  list-style: none;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  scrollbar-width: thin;
  scrollbar-color: var(--color-line) transparent;
  -webkit-overflow-scrolling: touch;
}

.page-topics .topics-rail::-webkit-scrollbar {
  height: 6px;
}

.page-topics .topics-rail::-webkit-scrollbar-thumb {
  background: var(--color-line);
  border-radius: var(--radius-pill);
}

.page-topics .topics-rail__card {
  flex: 0 0 var(--tp-card-w);
  scroll-snap-align: start;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  padding: var(--space-3);
  border-radius: var(--radius-lg);
  background: var(--color-surface);
  border: var(--border-thin) solid var(--color-line);
  box-shadow: var(--shadow-1);
  transition: transform 0.22s ease, box-shadow 0.22s ease;
}

.page-topics .topics-lane--alt .topics-rail__card {
  background: var(--color-surface);
}

.page-topics .topics-rail__card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-2);
}

.page-topics .topics-rail__card .tag {
  align-self: flex-start;
}

.page-topics .topics-rail__title {
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: var(--weight-heading);
  line-height: 1.32;
  letter-spacing: var(--tracking-heading);
  margin: 0;
  color: var(--color-ink);
}

.page-topics .topics-rail__text {
  margin: 0;
  font-size: var(--text-sm);
  line-height: 1.7;
  color: var(--color-ink-soft);
}

/* ---------- 续写区块 ---------- */

.page-topics .topics-write {
  position: relative;
  padding-block: var(--tp-pad-y);
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  overflow: hidden;
}

.page-topics .topics-write::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(
    210deg,
    color-mix(in srgb, var(--color-primary) 34%, transparent) 0%,
    transparent 58%
  );
  pointer-events: none;
}

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

.page-topics .topics-write__marker {
  color: color-mix(in srgb, var(--color-contrast-ink) 66%, transparent);
  margin: 0 0 var(--space-3);
}

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

.page-topics .topics-write__title {
  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);
  margin: 0 0 var(--space-3);
  color: var(--color-contrast-ink);
  text-wrap: balance;
}

.page-topics .topics-write__lede {
  margin: 0;
  max-width: var(--measure);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: color-mix(in srgb, var(--color-contrast-ink) 80%, transparent);
}

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

.page-topics .topics-write__item {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: var(--space-3);
  padding: var(--space-3);
  border-radius: var(--radius-lg);
  border: var(--border-thin) solid var(--color-contrast-line);
  background: color-mix(in srgb, var(--color-contrast-surface) 60%, transparent);
}

.page-topics .topics-write__num {
  font-size: var(--text-sm);
  color: var(--color-contrast-accent);
  padding-top: 3px;
}

.page-topics .topics-write__item-title {
  margin: 0 0 4px;
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: var(--weight-heading);
  line-height: 1.32;
  letter-spacing: var(--tracking-heading);
  color: var(--color-contrast-ink);
}

.page-topics .topics-write__item-text {
  margin: 0;
  font-size: var(--text-sm);
  line-height: 1.72;
  color: color-mix(in srgb, var(--color-contrast-ink) 76%, transparent);
}

.page-topics .topics-link {
  color: var(--color-contrast-accent);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-thickness: 1px;
}

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

.page-topics .topics-write__outro {
  grid-column: 1 / -1;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-3);
  margin: var(--space-2) 0 0;
  padding-top: var(--space-4);
  border-top: var(--border-thin) solid var(--color-contrast-line);
  font-size: var(--text-base);
  color: color-mix(in srgb, var(--color-contrast-ink) 80%, transparent);
}

.page-topics .topics-write__outro .btn {
  text-decoration: none;
}

/* ---------- 桌面端 ---------- */

@media (min-width: 720px) {
  .page-topics .topics-index {
    grid-template-columns: repeat(12, 1fr);
    gap: var(--space-3);
  }

  .page-topics .topics-index__item:nth-child(1) { grid-column: span 7; }
  .page-topics .topics-index__item:nth-child(2) { grid-column: span 5; }
  .page-topics .topics-index__item:nth-child(3) { grid-column: span 5; }
  .page-topics .topics-index__item:nth-child(4) { grid-column: span 4; }
  .page-topics .topics-index__item:nth-child(5) { grid-column: span 3; }

  .page-topics .topics-write__grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.05fr);
    align-items: start;
    column-gap: var(--space-8);
  }

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

@media (min-width: 1024px) {
  .page-topics .topics-lane__grid {
    grid-template-columns: minmax(240px, 320px) minmax(0, 1fr);
    column-gap: var(--space-8);
  }

  .page-topics .topics-lane__head {
    position: sticky;
    top: 104px;
  }

  .page-topics .topics-lane__media {
    max-width: 520px;
  }

  .page-topics .topics-rail__card {
    flex-basis: 296px;
  }
}

@media (min-width: 1200px) {
  .page-topics .topics-hero__inner {
    padding-right: 12%;
  }
}