.page-about {
  --about-rule: rgba(156, 198, 214, 0.28);
  --about-rule-ink: rgba(16, 28, 40, 0.12);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding-block: clamp(20px, 4vw, 40px) clamp(40px, 6vw, 72px);
}

.page-about .about-hero__frame {
  position: relative;
  margin-top: clamp(16px, 3vw, 28px);
  padding: clamp(20px, 4vw, 44px);
  border: 1px solid rgba(240, 138, 36, 0.4);
  border-radius: var(--radius-lg);
  background:
    linear-gradient(155deg, rgba(240, 138, 36, 0.16), rgba(11, 26, 46, 0) 58%),
    rgba(22, 48, 76, 0.5);
  overflow: hidden;
}

.page-about .about-hero__frame::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 5px;
  background-image: repeating-linear-gradient(90deg, var(--c-sunset) 0 1px, transparent 1px 16px);
  opacity: 0.6;
}

.page-about .about-hero__head h1 {
  margin: 12px 0 0;
  font-size: clamp(30px, 5.4vw, 54px);
  line-height: 1.14;
  letter-spacing: -0.02em;
}

.page-about .about-hero__head .lead {
  margin-top: clamp(14px, 2vw, 20px);
  max-width: 44em;
  color: var(--c-snow);
}

.page-about .about-hero__metrics {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px 20px;
  margin: clamp(24px, 3.4vw, 36px) 0 0;
  padding-top: clamp(20px, 3vw, 28px);
  border-top: 1px solid var(--about-rule);
}

.page-about .about-hero__metric {
  display: flex;
  flex-direction: column-reverse;
  gap: 4px;
  margin: 0;
}

.page-about .about-hero__metric dt {
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--c-snow);
}

.page-about .about-hero__metric dd {
  margin: 0;
  font-family: var(--font-score);
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  line-height: 1;
}

.page-about .about-num {
  font-size: clamp(32px, 5vw, 46px);
  color: var(--c-amber);
}

.page-about .about-hero__figure {
  margin: clamp(26px, 4vw, 40px) 0 0;
}

.page-about .about-hero__figure img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: var(--radius-lg);
}

/* ---------- 沿革刻度带 ---------- */
.page-about .about-axis {
  padding-block: clamp(28px, 4vw, 44px);
  border-top: 1px solid var(--about-rule);
}

.page-about .about-axis__list {
  display: flex;
  gap: 0;
  margin: clamp(12px, 2vw, 20px) 0 0;
  padding: 0 0 6px;
  list-style: none;
  overflow-x: auto;
  scroll-snap-type: x proximity;
  -webkit-overflow-scrolling: touch;
}

.page-about .about-axis__node {
  position: relative;
  flex: 0 0 auto;
  min-width: 200px;
  scroll-snap-align: start;
  padding-top: 22px;
}

.page-about .about-axis__node::before {
  content: "";
  position: absolute;
  top: 7px;
  left: 0;
  right: 0;
  height: 1px;
  background: var(--about-rule);
}

.page-about .about-axis__link {
  display: block;
  padding-right: 20px;
  text-decoration: none;
  color: inherit;
}

.page-about .about-axis__dot {
  position: absolute;
  top: 2px;
  left: 0;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--c-night);
  border: 2px solid var(--c-snow);
  transition: background var(--t-mid) var(--ease), border-color var(--t-mid) var(--ease), transform var(--t-mid) var(--ease);
}

.page-about .about-axis__node:hover .about-axis__dot,
.page-about .about-axis__node:focus-within .about-axis__dot {
  background: var(--c-sunset);
  border-color: var(--c-amber);
  transform: scale(1.18);
}

.page-about .about-axis__label {
  display: block;
  font-family: var(--font-heading);
  font-weight: 800;
  font-size: 15px;
  letter-spacing: 0.01em;
  color: var(--c-paper);
}

.page-about .about-axis__note {
  display: block;
  max-height: 0;
  overflow: hidden;
  opacity: 0;
  font-size: 14px;
  line-height: 1.65;
  color: var(--c-snow);
  transition: max-height var(--t-mid) var(--ease), opacity var(--t-mid) var(--ease), margin-top var(--t-mid) var(--ease);
}

.page-about .about-axis__node:hover .about-axis__note,
.page-about .about-axis__node:focus-within .about-axis__note {
  max-height: 7em;
  margin-top: 8px;
  opacity: 1;
}

/* ---------- 通用章节 ---------- */
.page-about .section {
  scroll-margin-top: calc(var(--header-h) + 16px);
}

.page-about .section h2 {
  margin: 12px 0 0;
  font-size: clamp(24px, 3.4vw, 36px);
  line-height: 1.2;
}

/* ---------- 沿革 ---------- */
.page-about .about-trail__figure {
  margin: clamp(24px, 3.4vw, 36px) 0 0;
}

.page-about .about-trail__figure img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: var(--radius-lg);
}

.page-about .about-trail__text p {
  margin: 0 0 1em;
  max-width: 38em;
  line-height: 1.75;
  color: var(--fg);
}

.page-about .about-trail__marks {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
  margin: clamp(28px, 4vw, 44px) 0 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--about-rule-ink);
}

.page-about .about-trail__mark {
  position: relative;
  padding: 22px 0 22px clamp(56px, 9vw, 84px);
  border-bottom: 1px solid var(--about-rule-ink);
}

.page-about .about-trail__year {
  position: absolute;
  left: 0;
  top: 18px;
  font-family: var(--font-serif);
  font-size: clamp(30px, 4.6vw, 46px);
  line-height: 1;
  color: var(--c-paper-edge);
  font-weight: 700;
  letter-spacing: -0.02em;
}

.page-about .about-trail__mark h3 {
  margin: 0 0 6px;
  font-size: 17px;
  font-weight: 800;
}

.page-about .about-trail__mark p {
  margin: 0;
  max-width: 36em;
  font-size: 15px;
  line-height: 1.7;
  color: var(--fg-muted);
}

/* ---------- 数据 ---------- */
.page-about .about-data__lead {
  margin-top: clamp(14px, 2vw, 20px);
  max-width: 42em;
}

.page-about .about-flow {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  margin: clamp(24px, 3.4vw, 36px) 0 0;
}

.page-about .about-flow__source,
.page-about .about-flow__check {
  position: relative;
  padding: clamp(18px, 2.6vw, 26px);
  border-radius: var(--radius-lg);
  background: var(--surface-raised);
  border: 1px solid var(--about-rule-ink);
}

.page-about .about-flow__source--a {
  border-left: 4px solid var(--c-snow);
}

.page-about .about-flow__source--b {
  border-left: 4px solid var(--c-night-2);
}

.page-about .about-flow__check {
  border-left: 4px solid var(--c-sunset);
  background: linear-gradient(140deg, rgba(240, 138, 36, 0.14), rgba(255, 196, 107, 0.06));
}

.page-about .about-flow__tag {
  display: inline-block;
  margin-bottom: 8px;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--fg-muted);
}

.page-about .about-flow__tag--sun {
  color: var(--c-amber-deep);
}

.page-about .about-flow p {
  margin: 0;
  font-size: 15px;
  line-height: 1.7;
}

.page-about .about-data__facts {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
  margin: clamp(26px, 3.6vw, 40px) 0 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--about-rule-ink);
}

.page-about .about-data__facts li {
  padding: 14px 0;
  border-bottom: 1px solid var(--about-rule-ink);
  font-size: 15px;
  line-height: 1.6;
  color: var(--fg);
}

.page-about .about-data__facts strong {
  font-family: var(--font-score);
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  font-size: 19px;
  color: var(--c-amber-deep);
  margin: 0 3px;
}

/* ---------- 团队 ---------- */
.page-about .about-team__layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(22px, 3.4vw, 36px);
  margin-top: clamp(22px, 3vw, 32px);
}

.page-about .about-team__intro {
  margin: 0 0 18px;
  max-width: 40em;
  line-height: 1.75;
}

.page-about .about-team__card {
  margin: 0 0 14px;
  padding: 0;
  overflow: hidden;
}

.page-about .about-team__card:last-of-type {
  margin-bottom: 0;
}

.page-about .about-team__card summary {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 16px clamp(16px, 2.4vw, 22px);
  cursor: pointer;
  list-style: none;
  transition: background var(--t-fast) var(--ease);
}

.page-about .about-team__card summary::-webkit-details-marker {
  display: none;
}

.page-about .about-team__card summary:hover {
  background: rgba(240, 138, 36, 0.08);
}

.page-about .about-team__role {
  flex: 1 1 auto;
  font-family: var(--font-heading);
  font-weight: 800;
  font-size: 17px;
  color: var(--fg);
}

.page-about .about-team__size {
  flex: 0 0 auto;
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--fg-muted);
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  padding: 3px 10px;
}

.page-about .about-team__card[open] summary {
  border-bottom: 1px solid var(--about-rule-ink);
}

.page-about .about-team__card p {
  margin: 0;
  padding: 14px clamp(16px, 2.4vw, 22px) 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--fg-muted);
}

.page-about .about-team__card p:last-child {
  padding-bottom: 18px;
}

.page-about .about-team__figure {
  margin: 0;
}

.page-about .about-team__figure img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: var(--radius-lg);
}

/* ---------- 覆盖 ---------- */
.page-about .about-reach__layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(22px, 3.4vw, 36px);
  margin-top: clamp(22px, 3vw, 32px);
}

.page-about .about-reach__text p {
  margin: 0 0 1em;
  max-width: 38em;
  line-height: 1.75;
}

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

.page-about .about-reach__map {
  padding: clamp(20px, 3vw, 28px);
  border-radius: var(--radius-lg);
  background: var(--surface-raised);
  border: 1px solid var(--about-rule-ink);
}

.page-about .about-reach__dots {
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-reach__dots li {
  width: 14px;
  height: 14px;
  border-radius: 2px;
  background: rgba(16, 28, 40, 0.13);
}

.page-about .about-reach__dots li.is-nw {
  background: var(--c-jade);
}

.page-about .about-reach__legend {
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 18px 0 0;
  font-size: 14px;
  color: var(--fg-muted);
}

.page-about .about-reach__key {
  width: 14px;
  height: 14px;
  border-radius: 2px;
  background: var(--c-jade);
  flex: 0 0 auto;
}

/* ---------- 下一步 ---------- */
.page-about .about-next__lead {
  margin-top: clamp(12px, 1.8vw, 18px);
  color: var(--c-snow);
}

.page-about .about-next__links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(22px, 3vw, 32px);
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .about-hero__metrics {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-trail__marks {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: clamp(20px, 3vw, 36px);
  }

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

  .page-about .about-flow__check {
    grid-column: 1 / -1;
  }

  .page-about .about-data__facts {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: clamp(20px, 3vw, 36px);
  }
}

@media (min-width: 900px) {
  .page-about .about-trail__body {
    display: grid;
    grid-template-columns: minmax(0, 1fr);
  }

  .page-about .about-team__layout {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .about-reach__layout {
    grid-template-columns: minmax(0, 1.2fr) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .about-trail__marks {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-trail__mark {
    padding: 22px 0 22px 0;
    border-bottom: 0;
    border-top: 3px solid var(--c-sunset);
    margin-right: clamp(14px, 2vw, 24px);
    padding-top: 18px;
  }

  .page-about .about-trail__mark:last-child {
    margin-right: 0;
  }

  .page-about .about-trail__mark .about-trail__year {
    position: static;
    display: block;
    margin-bottom: 10px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-axis__note,
  .page-about .about-axis__dot,
  .page-about .about-team__card summary {
    transition: none;
  }
}