.page-topics {
  --tp-pad: clamp(var(--space-3), 4vw, var(--space-6));
  --tp-pad-lg: clamp(var(--space-4), 6vw, var(--space-8));
  background: var(--color-surface);
  color: var(--color-ink);
}

/* ---------- 首屏 ---------- */
.page-topics .tp-hero {
  padding-top: var(--space-4);
}

.page-topics .tp-hero__inner {
  display: grid;
  gap: var(--space-2);
  margin-top: var(--space-2);
  margin-bottom: var(--space-8);
}

@media (min-width: 1000px) {
  .page-topics .tp-hero__inner {
    grid-template-columns: 7fr 5fr;
    gap: 0;
  }
}

.page-topics .tp-hero__deep {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  padding: var(--tp-pad-lg);
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}

.page-topics .tp-hero__title {
  margin: 0;
  font-family: var(--font-heading);
  font-size: var(--text-display);
  font-weight: var(--weight-heading);
  line-height: 1.02;
  letter-spacing: -0.03em;
}

.page-topics .tp-hero__lede {
  margin: 0;
  max-width: 46ch;
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: color-mix(in srgb, var(--color-contrast-ink) 82%, transparent);
}

.page-topics .tp-collage {
  display: grid;
  grid-template-columns: repeat(6, minmax(0, 1fr));
  gap: var(--space-1);
  margin-top: auto;
  padding-top: var(--space-3);
}

.page-topics .tp-tile {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: calc(var(--space-1) / 2);
  min-height: calc(var(--space-4) * 2);
  padding: var(--space-2);
  border: var(--border-thin) solid var(--color-contrast-line);
  color: var(--color-contrast-ink);
  text-decoration: none;
  transition: background-color 180ms linear, border-color 180ms linear;
}

.page-topics .tp-tile:hover,
.page-topics .tp-tile:focus-visible {
  background: color-mix(in srgb, var(--color-contrast-ink) 10%, transparent);
  border-color: var(--color-contrast-accent);
}

.page-topics .tp-tile--a {
  grid-column: span 6;
  grid-row: span 2;
  background: var(--color-primary);
  border-color: var(--color-primary);
}

.page-topics .tp-tile--b,
.page-topics .tp-tile--c,
.page-topics .tp-tile--d,
.page-topics .tp-tile--e {
  grid-column: span 3;
}

.page-topics .tp-tile--f {
  grid-column: span 6;
}

@media (min-width: 560px) {
  .page-topics .tp-tile--a { grid-column: span 4; }
  .page-topics .tp-tile--b,
  .page-topics .tp-tile--c,
  .page-topics .tp-tile--d,
  .page-topics .tp-tile--e,
  .page-topics .tp-tile--f { grid-column: span 2; }
}

.page-topics .tp-tile--a:hover,
.page-topics .tp-tile--a:focus-visible {
  background: var(--color-primary);
  border-color: var(--color-primary-ink);
  filter: brightness(1.12);
}

.page-topics .tp-tile__k {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-contrast-accent);
}

.page-topics .tp-tile__n {
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: -0.01em;
}

.page-topics .tp-tile--a .tp-tile__n {
  font-size: var(--text-xl);
}

.page-topics .tp-tile__d {
  font-size: var(--text-xs);
  line-height: 1.45;
  color: color-mix(in srgb, var(--color-contrast-ink) 68%, transparent);
}

.page-topics .tp-tile--a,
.page-topics .tp-tile--a .tp-tile__k,
.page-topics .tp-tile--a .tp-tile__n,
.page-topics .tp-tile--a .tp-tile__d {
  color: var(--color-primary-ink);
}

/* 首屏右侧数据面 */
.page-topics .tp-hero__light {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  justify-content: center;
  padding: var(--tp-pad-lg);
  background: var(--color-surface-alt);
  border: var(--border-thin) solid var(--color-line);
}

.page-topics .tp-stat {
  padding-top: var(--space-2);
  border-top: var(--border-thin) solid var(--color-line);
}

.page-topics .tp-stat--first,
.page-topics .tp-stat:first-child {
  padding-top: 0;
  border-top: none;
}

.page-topics .tp-stat__num {
  display: block;
  margin-bottom: calc(var(--space-1) / 2);
  font-family: var(--font-mono);
  font-size: var(--text-figure);
  font-weight: var(--weight-heading);
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--color-primary);
}

.page-topics .tp-stat--accent .tp-stat__num {
  color: var(--color-accent);
}

.page-topics .tp-stat__cap {
  margin: 0 0 calc(var(--space-1) / 2);
  font-size: var(--text-sm);
  font-weight: var(--weight-heading);
  color: var(--color-ink);
}

.page-topics .tp-stat__d {
  margin: 0;
  max-width: 34ch;
  font-size: var(--text-sm);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
}

/* ---------- 专题目录 ---------- */
.page-topics .tp-deck-section {
  padding-bottom: var(--space-8);
}

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

.page-topics .tp-deckhead h2 {
  margin: var(--space-1) 0 var(--space-2);
  font-family: var(--font-heading);
  font-size: var(--text-3xl);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
}

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

.page-topics .tp-filters {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1);
  margin-bottom: var(--space-4);
}

.page-topics .tp-filter {
  padding: calc(var(--space-1) * 0.75) var(--space-2);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-sm);
  background: transparent;
  color: var(--color-ink-soft);
  font-family: var(--font-body);
  font-size: var(--text-sm);
  cursor: pointer;
  transition: background-color 160ms linear, border-color 160ms linear, color 160ms linear;
}

.page-topics .tp-filter:hover {
  border-color: var(--color-primary);
  color: var(--color-ink);
}

.page-topics .tp-filter[aria-pressed="true"] {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-primary-ink);
}

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

.page-topics .tp-card {
  position: relative;
  overflow: hidden;
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border: var(--border-thin) solid var(--color-contrast-surface);
}

.page-topics .tp-card::before {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: calc(var(--space-1) / 2);
  z-index: 2;
  background: var(--color-contrast-accent);
  transform: scaleY(0);
  transform-origin: top center;
  transition: transform 200ms linear;
}

.page-topics .tp-card:hover::before,
.page-topics .tp-card:focus-within::before {
  transform: scaleY(1);
}

@media (min-width: 900px) {
  .page-topics .tp-card--1 { width: 100%; }
  .page-topics .tp-card--2 { width: 95%; }
  .page-topics .tp-card--3 { width: 90%; }
  .page-topics .tp-card--4 { width: 85%; }
  .page-topics .tp-card--5 { width: 80%; }
  .page-topics .tp-card--6 { width: 75%; }
}

.page-topics .tp-card__bg {
  position: absolute;
  inset: 0;
}

.page-topics .tp-card__img {
  display: block;
  width: 100%;
  height: 100%;
  max-width: 100%;
  object-fit: cover;
}

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

.page-topics .tp-card__inner {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  padding: var(--tp-pad-lg);
  min-height: calc(var(--space-8) * 4);
}

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

.page-topics .tp-tag {
  padding: calc(var(--space-1) * 0.5) var(--space-1);
  border-radius: var(--radius-sm);
  background: var(--color-primary);
  color: var(--color-primary-ink);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.04em;
}

.page-topics .tp-card__cat {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: color-mix(in srgb, var(--color-contrast-ink) 62%, transparent);
}

.page-topics .tp-card__title {
  margin: 0;
  font-family: var(--font-heading);
  font-size: var(--text-2xl);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: -0.015em;
}

.page-topics .tp-card__lede {
  margin: 0;
  max-width: 62ch;
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: color-mix(in srgb, var(--color-contrast-ink) 84%, transparent);
}

.page-topics .tp-points {
  display: grid;
  gap: var(--space-1);
  margin: 0;
  padding: 0;
  max-width: 76ch;
  list-style: none;
}

.page-topics .tp-points li {
  padding-top: var(--space-1);
  border-top: var(--border-thin) solid var(--color-contrast-line);
  font-size: var(--text-sm);
  line-height: var(--leading-body);
  color: color-mix(in srgb, var(--color-contrast-ink) 80%, transparent);
}

.page-topics .tp-points strong {
  display: inline-block;
  min-width: 6em;
  margin-right: var(--space-1);
  color: var(--color-contrast-accent);
  font-weight: var(--weight-heading);
}

.page-topics .tp-more {
  align-self: flex-start;
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  margin-top: var(--space-1);
  padding: calc(var(--space-1) * 0.75) var(--space-2);
  border: var(--border-thin) solid var(--color-contrast-line);
  border-radius: var(--radius-md);
  color: var(--color-contrast-ink);
  font-size: var(--text-sm);
  font-weight: var(--weight-heading);
  text-decoration: none;
  transition: border-color 180ms linear, background-color 180ms linear;
}

.page-topics .tp-more:hover,
.page-topics .tp-more:focus-visible {
  border-color: var(--color-contrast-accent);
  background: color-mix(in srgb, var(--color-contrast-accent) 16%, transparent);
}

.page-topics .tp-more__arrow {
  display: inline-block;
  transition: transform 180ms linear;
}

.page-topics .tp-more:hover .tp-more__arrow,
.page-topics .tp-more:focus-visible .tp-more__arrow {
  transform: translateX(calc(var(--space-1) / 2));
}

/* 浅底专题块 */
.page-topics .tp-card--plain {
  background: var(--color-surface-alt);
  color: var(--color-ink);
  border-color: var(--color-line);
}

.page-topics .tp-card--plain::before {
  background: var(--color-primary);
}

.page-topics .tp-card--plain .tp-card__cat {
  color: var(--color-ink-muted);
}

.page-topics .tp-card--plain .tp-card__lede {
  color: var(--color-ink-soft);
}

.page-topics .tp-card--plain .tp-points li {
  border-top-color: var(--color-line);
  color: var(--color-ink-soft);
}

.page-topics .tp-card--plain .tp-points strong {
  color: var(--color-primary);
}

.page-topics .tp-card--plain .tp-more {
  border-color: var(--color-line);
  color: var(--color-ink);
}

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

/* ---------- 专题与栏目对照 ---------- */
.page-topics .tp-contrast {
  padding-bottom: var(--space-8);
}

.page-topics .tp-contrast__title {
  margin: 0 0 var(--space-4);
  font-family: var(--font-heading);
  font-size: var(--text-2xl);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
}

.page-topics .tp-contrast__split {
  display: grid;
  border: var(--border-thin) solid var(--color-line);
}

@media (min-width: 820px) {
  .page-topics .tp-contrast__split {
    grid-template-columns: 1fr 1fr;
  }
  .page-topics .tp-contrast__pane--a {
    border-right: var(--border-thin) solid var(--color-line);
  }
}

.page-topics .tp-contrast__pane {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  padding: var(--tp-pad);
}

.page-topics .tp-contrast__pane--a {
  background: var(--color-surface-alt);
  color: var(--color-ink);
}

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

.page-topics .tp-contrast__pane h3 {
  margin: 0;
  font-family: var(--font-heading);
  font-size: var(--text-xl);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
}

.page-topics .tp-contrast__pane p {
  margin: 0;
  max-width: 48ch;
  font-size: var(--text-sm);
  line-height: var(--leading-body);
}

.page-topics .tp-contrast__pane--a p {
  color: var(--color-ink-soft);
}

.page-topics .tp-contrast__pane--b p {
  color: color-mix(in srgb, var(--color-contrast-ink) 82%, transparent);
}

/* ---------- 下一步 ---------- */
.page-topics .tp-next {
  padding-bottom: var(--space-8);
}

.page-topics .tp-next__box {
  padding: var(--tp-pad-lg);
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}

.page-topics .tp-next__box h2 {
  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);
}

.page-topics .tp-next__lede {
  margin: 0 0 var(--space-4);
  max-width: 60ch;
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: color-mix(in srgb, var(--color-contrast-ink) 80%, transparent);
}

.page-topics .tp-path {
  display: grid;
  gap: var(--space-1);
}

@media (min-width: 760px) {
  .page-topics .tp-path {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: var(--space-2);
  }
}

.page-topics .tp-path__step {
  display: flex;
  flex-direction: column;
  gap: calc(var(--space-1) / 2);
  padding: var(--space-2) var(--space-2) var(--space-2) var(--space-3);
  border-left: var(--border-thick) solid var(--color-contrast-accent);
  background: color-mix(in srgb, var(--color-contrast-ink) 6%, transparent);
  color: var(--color-contrast-ink);
  text-decoration: none;
  transition: background-color 180ms linear;
}

.page-topics .tp-path__step:hover,
.page-topics .tp-path__step:focus-visible {
  background: color-mix(in srgb, var(--color-contrast-accent) 20%, transparent);
}

.page-topics .tp-path__label {
  font-family: var(--font-heading);
  font-size: var(--text-base);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
}

.page-topics .tp-path__note {
  font-size: var(--text-sm);
  line-height: var(--leading-body);
  color: color-mix(in srgb, var(--color-contrast-ink) 74%, transparent);
}

.page-topics .tp-next__foot {
  margin: var(--space-4) 0 0;
  max-width: 74ch;
  font-size: var(--text-sm);
  line-height: var(--leading-body);
  color: color-mix(in srgb, var(--color-contrast-ink) 78%, transparent);
}

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

/* ---------- 窄屏收束 ---------- */
@media (max-width: 899px) {
  .page-topics .tp-card__inner {
    min-height: 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-topics .tp-tile,
  .page-topics .tp-more,
  .page-topics .tp-more__arrow,
  .page-topics .tp-path__step,
  .page-topics .tp-filter,
  .page-topics .tp-card::before {
    transition: none;
  }
  .page-topics .tp-tile--a:hover,
  .page-topics .tp-tile--a:focus-visible {
    filter: none;
  }
}