.page-about {
  --about-gap: clamp(56px, 9vw, 132px);
  --about-measure: 62ch;
  --about-plate: clamp(18px, 2.2vw, 26px);
  position: relative;
  overflow-x: clip;
}

/* ---------- 序章 ---------- */

.page-about .about-hero {
  position: relative;
  isolation: isolate;
  padding-top: calc(var(--header-h) + clamp(40px, 7vw, 96px));
  padding-bottom: clamp(32px, 5vw, 64px);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: -8% -16% 12%;
  z-index: -1;
  pointer-events: none;
  background:
    radial-gradient(56% 50% at 80% 6%, rgba(56, 245, 208, 0.17), transparent 62%),
    radial-gradient(52% 46% at 4% 24%, rgba(30, 111, 92, 0.34), transparent 66%),
    radial-gradient(38% 36% at 52% 92%, rgba(255, 180, 84, 0.07), transparent 72%);
}

.page-about .about-title {
  margin: clamp(16px, 2.4vw, 26px) 0 clamp(20px, 3vw, 32px);
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(36px, 8.6vw, 96px);
  line-height: 1.04;
  letter-spacing: -0.012em;
  color: var(--text);
  max-width: 18ch;
}

.page-about .about-hero .lede {
  max-width: 60ch;
}

.page-about .origin-index {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(18px, 2.4vw, 28px);
  margin: clamp(34px, 4.6vw, 56px) 0 0;
  max-width: 760px;
}

.page-about .origin-index dt {
  margin: 0;
  font-size: 13px;
  line-height: 1.55;
  letter-spacing: 0.03em;
  color: var(--muted);
}

.page-about .origin-index dd {
  margin: 8px 0 0;
  font-family: var(--font-mono);
  font-size: clamp(20px, 2.4vw, 28px);
  line-height: 1.2;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}

.page-about .hero-frame {
  margin: clamp(34px, 5.6vw, 68px) 0 0;
}

.page-about .hero-frame img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 2 / 1;
  object-fit: cover;
}

.page-about .media-figure figcaption {
  margin-top: 12px;
  font-size: 13px;
  line-height: 1.65;
  color: var(--muted);
}

/* ---------- 策展动线 ---------- */

.page-about .story-track {
  padding-bottom: clamp(48px, 7vw, 96px);
}

.page-about .chapter {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(18px, 2.6vw, 32px);
  padding-block: clamp(52px, 8vw, 120px);
}

.page-about .chapter__marker {
  display: flex;
  align-items: baseline;
  gap: 14px;
}

.page-about .chapter-num {
  font-family: var(--font-mono);
  font-weight: 200;
  font-size: clamp(64px, 12vw, 112px);
  line-height: 0.82;
  letter-spacing: -0.05em;
  color: rgba(56, 245, 208, 0.14);
  -webkit-text-stroke: 1px rgba(56, 245, 208, 0.28);
  font-variant-numeric: tabular-nums;
}

.page-about .chapter-kicker {
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--muted);
  white-space: nowrap;
}

.page-about .chapter__body {
  max-width: var(--about-measure);
}

.page-about .chapter__body h2 {
  margin: 0 0 clamp(18px, 2.4vw, 28px);
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(24px, 3.4vw, 42px);
  line-height: 1.2;
  letter-spacing: -0.008em;
  color: var(--text);
}

.page-about .chapter__body p {
  margin: 0 0 1.15em;
  font-size: 16px;
  line-height: 1.85;
  color: var(--text);
}

.page-about .chapter__body p:last-child {
  margin-bottom: 0;
}

.page-about .chapter__body a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid var(--line-strong);
  padding-bottom: 1px;
  transition: border-color 0.25s var(--ease), color 0.25s var(--ease);
}

.page-about .chapter__body a:hover,
.page-about .chapter__body a:focus-visible {
  color: var(--mist);
  border-bottom-color: var(--mist);
}

/* ---------- 数据三条线 ---------- */

.page-about .data-lanes {
  list-style: none;
  margin: clamp(26px, 3.4vw, 38px) 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(12px, 1.6vw, 18px);
}

.page-about .lane {
  position: relative;
  padding: var(--about-plate) clamp(18px, 2.1vw, 24px);
  background-color: var(--panel);
  background-image: linear-gradient(155deg, rgba(56, 245, 208, 0.08), transparent 58%);
  box-shadow: inset 0 0 0 1px rgba(56, 245, 208, 0.13);
  clip-path: polygon(
    0 0,
    calc(100% - var(--cut)) 0,
    100% var(--cut),
    100% 100%,
    var(--cut) 100%,
    0 calc(100% - var(--cut))
  );
}

.page-about .lane__name {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 17px;
  line-height: 1.35;
  color: var(--text);
}

.page-about .lane__time {
  margin: 8px 0 12px;
  font-family: var(--font-mono);
  font-size: 14px;
  line-height: 1.4;
  letter-spacing: 0.01em;
  color: var(--mist);
}

.page-about .lane__note {
  margin: 0;
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
}

/* ---------- 口径说明牌 ---------- */

.page-about .rule-set {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(14px, 1.8vw, 20px);
  margin-top: clamp(26px, 3.4vw, 40px);
}

.page-about .rule {
  padding: clamp(16px, 2vw, 22px) clamp(16px, 2vw, 22px) clamp(16px, 2vw, 22px)
    clamp(20px, 2.4vw, 28px);
  background: var(--panel);
  border-left: 2px solid var(--line-strong);
  outline: none;
  transition: border-color 0.3s var(--ease), background-color 0.3s var(--ease);
}

.page-about .rule:hover,
.page-about .rule:focus-within,
.page-about .rule:focus {
  border-left-color: var(--cyan);
  background: var(--panel-2);
}

.page-about .rule:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
}

.page-about .rule__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 16px;
  line-height: 1.4;
  color: var(--text);
}

.page-about .rule__short {
  margin: 7px 0 0;
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.5;
  color: var(--cyan);
}

.page-about .rule__full {
  margin: 10px 0 0;
  max-height: 320px;
  overflow: hidden;
  opacity: 1;
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
  transition: max-height 0.38s var(--ease), opacity 0.28s var(--ease),
    margin-top 0.38s var(--ease);
}

/* ---------- 区间示意 ---------- */

.page-about .zone-figure {
  margin: clamp(26px, 3.4vw, 42px) 0;
  padding: clamp(14px, 1.8vw, 22px);
  background: linear-gradient(180deg, rgba(18, 51, 42, 0.6), rgba(6, 17, 13, 0) 88%);
}

.page-about .zone-band {
  display: block;
  width: 100%;
  height: auto;
}

.page-about .zone-band rect {
  fill: rgba(30, 111, 92, 0.3);
  stroke: rgba(56, 245, 208, 0.4);
  stroke-width: 1;
}

.page-about .zone-band text {
  font-family: var(--font-mono);
  font-size: 22px;
  fill: var(--muted);
  text-anchor: middle;
}

.page-about .zone-band .zone-band__side {
  font-size: 20px;
  letter-spacing: 0.1em;
  fill: var(--pitch);
}

.page-about .zone-figure figcaption {
  margin-top: 14px;
  font-size: 13px;
  line-height: 1.65;
  color: var(--muted);
}

/* ---------- 团队分工 ---------- */

.page-about .roster {
  list-style: none;
  margin: clamp(24px, 3.2vw, 38px) 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(16px, 2vw, 22px);
}

.page-about .roster__item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  grid-template-rows: auto auto;
  column-gap: clamp(14px, 1.8vw, 20px);
  align-items: baseline;
}

.page-about .roster__count {
  grid-row: 1 / span 2;
  align-self: start;
  font-family: var(--font-mono);
  font-size: clamp(32px, 4.2vw, 46px);
  line-height: 1;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}

.page-about .roster__role {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 16px;
  line-height: 1.4;
  color: var(--text);
}

.page-about .roster__desc {
  margin-top: 5px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
}

/* ---------- 属地 ---------- */

.page-about .site-frame {
  margin: clamp(26px, 3.4vw, 40px) 0 0;
}

.page-about .site-frame img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 2 / 1;
  object-fit: cover;
}

/* ---------- 标签与纠错 ---------- */

.page-about .tag-row {
  list-style: none;
  margin: clamp(22px, 2.8vw, 32px) 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: clamp(8px, 1vw, 12px);
}

.page-about .correction-steps {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(14px, 1.8vw, 22px);
  margin: clamp(24px, 3.2vw, 36px) 0;
  padding: clamp(18px, 2.2vw, 26px);
  background-color: var(--panel);
  background-image: linear-gradient(200deg, rgba(255, 106, 61, 0.07), transparent 60%);
  box-shadow: inset 0 0 0 1px rgba(56, 245, 208, 0.13);
  clip-path: polygon(
    0 0,
    calc(100% - var(--cut)) 0,
    100% var(--cut),
    100% 100%,
    var(--cut) 100%,
    0 calc(100% - var(--cut))
  );
}

.page-about .correction-steps dt {
  margin: 0;
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--muted);
}

.page-about .correction-steps dd {
  margin: 8px 0 0;
  font-size: 14px;
  line-height: 1.65;
  color: var(--text);
}

.page-about .correction-steps .mono {
  font-family: var(--font-mono);
  font-size: 26px;
  line-height: 1;
  color: var(--amber);
  font-variant-numeric: tabular-nums;
  margin-right: 4px;
}

.page-about .coda-note {
  margin-top: clamp(24px, 3vw, 34px);
  padding-top: clamp(20px, 2.4vw, 28px);
  border-top: 1px solid var(--line-soft);
  font-size: 14px;
  line-height: 1.9;
  color: var(--muted);
}

/* ---------- 中屏 ---------- */

@media (min-width: 720px) {
  .page-about .origin-index {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .data-lanes {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .roster {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .correction-steps {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

/* ---------- 桌面策展动线 ---------- */

@media (min-width: 900px) {
  .page-about .chapter {
    grid-template-columns: minmax(170px, 3fr) minmax(0, 8fr);
    gap: clamp(32px, 5vw, 76px);
    align-items: start;
  }

  .page-about .chapter__marker {
    display: block;
    position: sticky;
    top: calc(var(--header-h-compact) + 28px);
  }

  .page-about .chapter-kicker {
    display: block;
    margin-top: 14px;
    padding-left: 4px;
  }

  .page-about .rule__full {
    max-height: 0;
    opacity: 0;
    margin-top: 0;
  }

  .page-about .rule:hover .rule__full,
  .page-about .rule:focus .rule__full,
  .page-about .rule:focus-within .rule__full {
    max-height: 320px;
    opacity: 1;
    margin-top: 10px;
  }
}

/* ---------- 动效降级 ---------- */

@media (prefers-reduced-motion: reduce) {
  .page-about .lane,
  .page-about .rule,
  .page-about .rule__full,
  .page-about .chapter__body a {
    transition: none;
  }
}