.page-about {
  --about-rail-w: 138px;
  --about-shadow: 0 18px 48px rgba(6, 14, 20, 0.28);
}

/* ---------- 面包屑 ---------- */
.page-about .about-crumb {
  padding-top: clamp(16px, 2.6vw, 28px);
  padding-bottom: clamp(8px, 1.4vw, 16px);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  color: var(--paper);
  border-radius: 0 0 var(--r-lg) var(--r-lg);
  padding: clamp(34px, 5.6vw, 74px) 0 clamp(40px, 6vw, 82px);
  background:
    radial-gradient(120% 150% at 6% -12%, rgba(47, 167, 155, 0.34), transparent 56%),
    radial-gradient(96% 132% at 94% 4%, rgba(31, 90, 120, 0.62), transparent 62%),
    linear-gradient(158deg, var(--ink) 0%, var(--ink-2) 50%, var(--ink) 100%);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--line-aurora), transparent);
}

.page-about .about-hero-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(26px, 4vw, 54px);
  align-items: center;
}

.page-about .about-hero .eyebrow {
  color: var(--aurora-bright);
  margin: 0 0 clamp(12px, 1.8vw, 18px);
}

.page-about .about-hero h1 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(2rem, 5.2vw, 4rem);
  line-height: 1.12;
  letter-spacing: -0.02em;
  color: var(--paper);
  margin: 0 0 clamp(16px, 2.2vw, 24px);
  max-width: 16em;
}

.page-about .about-hero-lede {
  font-size: clamp(0.98rem, 1.1vw, 1.06rem);
  line-height: 1.85;
  color: rgba(244, 241, 234, 0.82);
  max-width: 40em;
  margin: 0 0 clamp(22px, 3vw, 30px);
}

.page-about .about-hero-facts {
  display: flex;
  flex-wrap: wrap;
  gap: clamp(16px, 2.6vw, 36px);
  list-style: none;
  margin: 0 0 clamp(24px, 3.4vw, 34px);
  padding: 0;
}

.page-about .about-hero-facts li {
  display: flex;
  flex-direction: column;
  gap: 5px;
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  color: rgba(244, 241, 234, 0.58);
}

.page-about .about-hero-facts .num {
  font-family: var(--font-num);
  font-weight: 800;
  font-size: clamp(1.45rem, 2.6vw, 2rem);
  line-height: 1;
  letter-spacing: -0.01em;
  color: var(--gold);
  font-variant-numeric: tabular-nums;
}

.page-about .about-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.page-about .about-hero .btn-quiet {
  color: var(--paper);
  border-color: rgba(244, 241, 234, 0.32);
}

.page-about .about-hero .btn-quiet:hover,
.page-about .about-hero .btn-quiet:focus-visible {
  color: var(--aurora-bright);
  border-color: var(--aurora-bright);
}

.page-about .about-figure {
  margin: 0;
  border-radius: var(--r-lg);
  overflow: hidden;
  background: var(--ink-2);
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .about-hero-media {
  border: 1px solid rgba(70, 201, 188, 0.2);
  box-shadow: var(--about-shadow);
}

/* ---------- 主体骨架 ---------- */
.page-about .about-shell {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(18px, 3vw, 44px);
  padding-bottom: clamp(40px, 6vw, 84px);
}

.page-about .about-rail {
  display: none;
}

.page-about .about-rail-title {
  font-size: 0.7rem;
  letter-spacing: 0.2em;
  color: var(--stone);
  margin: 0 0 14px;
}

.page-about .about-rail-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 2px;
  border-left: 1px solid var(--line-soft);
}

.page-about .about-rail-link {
  position: relative;
  display: grid;
  grid-template-columns: 32px 1fr;
  align-items: baseline;
  gap: 8px;
  padding: 8px 0 8px 14px;
  text-decoration: none;
  color: var(--stone);
  font-size: 0.83rem;
  line-height: 1.4;
  transition: color 160ms ease;
}

.page-about .about-rail-link::before {
  content: "";
  position: absolute;
  left: -1px;
  top: 7px;
  bottom: 7px;
  width: 2px;
  background: transparent;
  transition: background 200ms ease;
}

.page-about .about-rail-link:hover,
.page-about .about-rail-link:focus-visible {
  color: var(--aurora-deep);
}

.page-about .about-rail-link:hover::before,
.page-about .about-rail-link:focus-visible::before {
  background: var(--aurora);
}

.page-about .about-rail-num {
  font-family: var(--font-num);
  font-weight: 800;
  font-size: 0.92rem;
  letter-spacing: 0.02em;
  color: var(--gold-ink);
  font-variant-numeric: tabular-nums;
}

.page-about .about-body {
  min-width: 0;
}

/* ---------- 章节 ---------- */
.page-about .about-chapter {
  padding: clamp(30px, 4.6vw, 58px) 0;
  border-top: 1px solid var(--line-soft);
}

.page-about .about-chapter:first-child {
  border-top: 0;
  padding-top: clamp(6px, 1.4vw, 18px);
}

.page-about .about-chapter-index {
  font-family: var(--font-num);
  font-weight: 800;
  font-size: clamp(2rem, 7.4vw, 3rem);
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--stone);
  opacity: 0.42;
  margin: 0 0 12px;
  font-variant-numeric: tabular-nums;
}

.page-about .about-chapter h2 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.5rem, 3.3vw, 2.4rem);
  line-height: 1.24;
  letter-spacing: -0.01em;
  color: var(--ink);
  margin: 0 0 clamp(14px, 2vw, 20px);
  max-width: 24em;
}

.page-about .about-copy {
  max-width: 40em;
}

.page-about .about-copy--tight {
  max-width: 34em;
}

.page-about .about-copy--wide {
  max-width: 52em;
}

.page-about .about-chapter .lede {
  max-width: 46em;
  margin: 0 0 clamp(16px, 2.2vw, 24px);
}

/* ---------- 02 使用场景 ---------- */
.page-about .about-personas {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(14px, 2vw, 20px);
}

.page-about .about-persona {
  position: relative;
  overflow: hidden;
  padding: clamp(22px, 2.8vw, 30px) clamp(20px, 2.4vw, 28px) clamp(20px, 2.4vw, 26px);
  background: var(--fog);
  border-radius: var(--r-md);
  border: 1px solid transparent;
  transition: border-color 200ms ease;
}

.page-about .about-persona::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: var(--aurora);
}

.page-about .about-persona--glacier::before {
  background: var(--glacier);
}

.page-about .about-persona--gold::before {
  background: var(--gold);
}

.page-about .about-persona:hover {
  border-color: var(--aurora);
}

.page-about .about-persona h3 {
  font-family: var(--font-body);
  font-size: 1.04rem;
  font-weight: 700;
  color: var(--ink);
  margin: 0 0 10px;
}

.page-about .about-persona p {
  margin: 0;
  font-size: 0.94rem;
  line-height: 1.78;
  color: var(--ink-2);
}

/* ---------- 03 时间轴 ---------- */
.page-about .about-timeline-figure {
  margin: clamp(20px, 2.8vw, 30px) 0;
  background: var(--fog);
  border-radius: var(--r-lg);
}

.page-about .about-track {
  position: relative;
  padding-left: 24px;
  display: grid;
  gap: 10px;
}

.page-about .about-track::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 14px;
  bottom: 14px;
  width: 1px;
  background: linear-gradient(180deg, var(--moss), var(--gold));
  opacity: 0.55;
}

.page-about .about-node {
  position: relative;
  background: var(--paper);
  border: 1px solid var(--line-soft);
  border-radius: var(--r-md);
  transition: border-color 200ms ease, background 200ms ease;
}

.page-about .about-node::before {
  content: "";
  position: absolute;
  left: -24px;
  top: 20px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--paper);
  border: 2px solid var(--moss);
  box-sizing: border-box;
}

.page-about .about-node--official::before {
  border-color: var(--gold);
}

.page-about .about-node--current::before {
  border-color: var(--gold);
  background: var(--gold);
}

.page-about .about-node[open] {
  border-color: var(--aurora);
  background: var(--fog);
}

.page-about .about-node summary {
  position: relative;
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: clamp(10px, 1.6vw, 18px);
  padding: clamp(14px, 1.8vw, 18px) clamp(40px, 4.4vw, 52px) clamp(14px, 1.8vw, 18px) clamp(16px, 2vw, 22px);
  cursor: pointer;
  list-style: none;
  border-radius: var(--r-md);
}

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

.page-about .about-node summary::after {
  content: "";
  position: absolute;
  right: clamp(16px, 2vw, 22px);
  top: 50%;
  width: 9px;
  height: 9px;
  margin-top: -6px;
  border-right: 2px solid var(--stone);
  border-bottom: 2px solid var(--stone);
  transform: rotate(45deg);
  transition: transform 200ms ease, border-color 200ms ease;
}

.page-about .about-node[open] summary::after {
  transform: rotate(-135deg);
  border-color: var(--aurora);
}

.page-about .about-node-year {
  font-family: var(--font-num);
  font-weight: 800;
  font-size: clamp(1.05rem, 2vw, 1.32rem);
  line-height: 1;
  letter-spacing: -0.01em;
  color: var(--glacier);
  font-variant-numeric: tabular-nums;
}

.page-about .about-node-title {
  font-size: 0.96rem;
  font-weight: 600;
  color: var(--ink);
}

.page-about .about-node-body {
  padding: 0 clamp(16px, 2vw, 22px) clamp(16px, 2vw, 20px);
}

.page-about .about-node-body p {
  margin: 0;
  font-size: 0.93rem;
  line-height: 1.78;
  color: var(--ink-2);
}

/* ---------- 04 团队 ---------- */
.page-about .about-team {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(20px, 3vw, 36px);
  margin-bottom: clamp(20px, 2.8vw, 30px);
}

.page-about .about-team-figure {
  background: var(--fog);
}

.page-about .about-team-roster {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: clamp(10px, 1.6vw, 14px);
}

.page-about .about-team-roster li {
  display: grid;
  grid-template-columns: auto 1fr;
  align-items: center;
  column-gap: 14px;
  row-gap: 4px;
  padding: clamp(14px, 1.8vw, 18px) clamp(16px, 2vw, 22px);
  background: var(--fog);
  border-radius: var(--r-md);
  border-left: 3px solid var(--glacier);
}

.page-about .about-team-roster .num {
  font-family: var(--font-num);
  font-weight: 800;
  font-size: 1.6rem;
  line-height: 1;
  color: var(--glacier);
  font-variant-numeric: tabular-nums;
}

.page-about .about-team-roster strong {
  font-size: 1rem;
  font-weight: 700;
  color: var(--ink);
}

.page-about .about-team-roster p {
  grid-column: 1 / -1;
  margin: 0;
  font-size: 0.89rem;
  line-height: 1.7;
  color: var(--stone);
}

/* ---------- 05 服务清单 ---------- */
.page-about .about-services {
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
}

.page-about .about-service {
  background: var(--paper);
  border: 1px solid var(--line-soft);
  border-radius: var(--r-md);
  transition: border-color 200ms ease, background 200ms ease;
}

.page-about .about-service[open] {
  border-color: var(--aurora);
  background: var(--fog);
}

.page-about .about-service summary {
  display: grid;
  grid-template-columns: auto 1fr auto auto;
  align-items: center;
  gap: clamp(10px, 1.6vw, 18px);
  padding: clamp(14px, 1.8vw, 20px) clamp(16px, 2.2vw, 24px);
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-service-num {
  font-family: var(--font-num);
  font-weight: 800;
  font-size: 0.92rem;
  letter-spacing: 0.04em;
  color: var(--gold-ink);
  font-variant-numeric: tabular-nums;
}

.page-about .about-service-name {
  font-size: 1rem;
  font-weight: 700;
  color: var(--ink);
}

.page-about .about-service-count {
  font-size: 0.76rem;
  letter-spacing: 0.12em;
  color: var(--stone);
  white-space: nowrap;
}

.page-about .about-service summary::after {
  content: "";
  width: 9px;
  height: 9px;
  margin-top: -4px;
  border-right: 2px solid var(--stone);
  border-bottom: 2px solid var(--stone);
  transform: rotate(45deg);
  transition: transform 200ms ease, border-color 200ms ease;
}

.page-about .about-service[open] summary::after {
  transform: rotate(-135deg);
  border-color: var(--aurora);
}

.page-about .about-service-list {
  list-style: none;
  margin: 0;
  padding: 0 clamp(16px, 2.2vw, 24px) clamp(16px, 2.2vw, 22px);
  display: grid;
  gap: 8px;
  font-size: 0.92rem;
  line-height: 1.7;
  color: var(--ink-2);
}

.page-about .about-service-list li {
  position: relative;
  padding-left: 16px;
}

.page-about .about-service-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.68em;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--aurora);
}

/* ---------- 07 数据与入口 ---------- */
.page-about .about-stats {
  list-style: none;
  margin: clamp(18px, 2.6vw, 26px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line-soft);
  border-radius: var(--r-lg);
  overflow: hidden;
}

.page-about .about-stats li {
  background: var(--fog);
  padding: clamp(18px, 2.4vw, 26px) clamp(14px, 1.8vw, 20px);
}

.page-about .about-stats .num {
  display: block;
  font-family: var(--font-num);
  font-weight: 800;
  font-size: clamp(1.65rem, 3.4vw, 2.45rem);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--gold-ink);
  margin-bottom: 8px;
  font-variant-numeric: tabular-nums;
}

.page-about .about-stat-label {
  display: block;
  font-size: 0.81rem;
  line-height: 1.6;
  letter-spacing: 0.02em;
  color: var(--ink-2);
}

.page-about .about-next {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
  margin-top: clamp(26px, 3.6vw, 40px);
}

.page-about .about-next-card {
  position: relative;
  display: grid;
  gap: 6px;
  padding: clamp(18px, 2.4vw, 24px) clamp(46px, 5vw, 56px) clamp(18px, 2.4vw, 24px) clamp(18px, 2.4vw, 24px);
  text-decoration: none;
  background: var(--ink);
  color: var(--paper);
  border-radius: var(--r-md);
  border: 1px solid transparent;
  transition: border-color 200ms ease, background 200ms ease;
}

.page-about .about-next-card:hover,
.page-about .about-next-card:focus-visible {
  background: var(--ink-2);
  border-color: var(--aurora);
}

.page-about .about-next-title {
  font-family: var(--font-display);
  font-size: 1.08rem;
  font-weight: 700;
  color: var(--aurora-bright);
}

.page-about .about-next-desc {
  font-size: 0.88rem;
  line-height: 1.7;
  color: rgba(244, 241, 234, 0.76);
}

.page-about .about-next-card .btn-arrow {
  position: absolute;
  right: clamp(18px, 2.4vw, 24px);
  top: 50%;
  transform: translateY(-50%);
  font-size: 1.1rem;
  color: var(--aurora-bright);
  transition: transform 200ms ease;
}

.page-about .about-next-card:hover .btn-arrow,
.page-about .about-next-card:focus-visible .btn-arrow {
  transform: translateY(-50%) translateX(4px);
}

.page-about .about-contact {
  margin-top: clamp(26px, 3.6vw, 38px);
  padding: clamp(20px, 2.8vw, 30px);
  border-radius: var(--r-lg);
  border: 1px solid var(--line-soft);
  background: var(--paper);
}

.page-about .about-contact-lead {
  margin: 0 0 clamp(14px, 2vw, 20px);
  font-size: 0.95rem;
  color: var(--ink);
}

.page-about .about-contact-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: clamp(12px, 1.8vw, 18px);
}

.page-about .about-contact-list li {
  display: grid;
  gap: 4px;
  padding-left: 14px;
  border-left: 3px solid var(--aurora);
}

.page-about .about-contact-key {
  font-size: 0.72rem;
  letter-spacing: 0.16em;
  color: var(--stone);
}

.page-about .about-contact-val {
  font-family: var(--font-num);
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: var(--glacier);
  word-break: break-all;
}

.page-about .about-contact-note {
  font-size: 0.84rem;
  line-height: 1.65;
  color: var(--stone);
}

/* ---------- 响应式 ---------- */
@media (max-width: 560px) {
  .page-about .about-node summary {
    grid-template-columns: 1fr auto;
    row-gap: 6px;
  }

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

@media (min-width: 760px) {
  .page-about .about-personas {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

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

@media (min-width: 900px) {
  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr);
  }

  .page-about .about-team {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr);
    align-items: start;
  }

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

@media (min-width: 1024px) {
  .page-about .about-shell {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: clamp(34px, 4.6vw, 76px);
  }

  .page-about .about-rail {
    display: block;
    position: sticky;
    top: 118px;
    align-self: start;
  }

  .page-about .about-chapter-index {
    display: none;
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about .about-rail-link,
  .page-about .about-rail-link::before,
  .page-about .about-node,
  .page-about .about-node summary::after,
  .page-about .about-service,
  .page-about .about-service summary::after,
  .page-about .about-next-card,
  .page-about .about-next-card .btn-arrow,
  .page-about .about-persona {
    transition: none;
  }
}
</final>