.page-about {
  --about-rail-w: 168px;
  --about-card-bg: linear-gradient(160deg, rgba(20, 21, 25, 0.96), rgba(20, 21, 25, 0.58));
}

/* ---------- 面包屑 ---------- */
.page-about .about-crumb-wrap {
  padding-top: clamp(14px, 2.4vw, 26px);
}

.page-about .breadcrumb {
  font-size: 12px;
  letter-spacing: 0.05em;
  color: var(--smoke);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  padding-block: clamp(24px, 3.6vw, 46px) clamp(44px, 6vw, 86px);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: -18% -28% 18% -12%;
  z-index: -1;
  pointer-events: none;
  transform: skewY(-5deg);
  background:
    radial-gradient(120% 92% at 10% 6%, rgba(183, 122, 61, 0.22), transparent 62%),
    radial-gradient(86% 76% at 94% 2%, rgba(64, 224, 208, 0.1), transparent 60%);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1px;
  z-index: -1;
  background: linear-gradient(90deg, transparent, var(--bronze-line) 20%, var(--cyan-line) 74%, transparent);
}

.page-about .about-hero-inner {
  display: grid;
  gap: clamp(26px, 4vw, 52px);
  align-items: center;
}

.page-about .about-hero-copy .eyebrow {
  color: var(--gold);
}

.page-about h1 {
  margin: 12px 0 0;
  font-family: var(--font-display);
  font-size: clamp(29px, 5.2vw, 52px);
  font-weight: 800;
  line-height: 1.16;
  letter-spacing: 0.02em;
  color: var(--paper);
  text-wrap: balance;
}

.page-about .about-lede {
  margin: 18px 0 0;
  max-width: 38em;
  color: var(--smoke);
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.86;
}

.page-about .about-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 24px;
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(26px, 3.4vw, 40px) 0 0;
  background: var(--hair);
  border: 1px solid var(--hair);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .about-stat {
  display: flex;
  flex-direction: column;
  gap: 5px;
  padding: 14px 14px 12px;
  background: rgba(10, 10, 12, 0.76);
}

.page-about .about-stat dd {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(17px, 2.2vw, 22px);
  line-height: 1.1;
  letter-spacing: 0.02em;
  color: var(--gold);
}

.page-about .about-stat dt {
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--smoke);
}

.page-about .about-hero-figure {
  position: relative;
  margin: 0;
  aspect-ratio: 7 / 5;
  overflow: hidden;
  border-radius: 6px;
  border: 1px solid var(--bronze-line);
  background: var(--graphite);
  box-shadow: 0 34px 80px -48px rgba(0, 0, 0, 0.95);
}

.page-about .about-hero-figure img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(0.9) contrast(1.06) brightness(0.9);
}

.page-about .about-hero-figcaption {
  position: absolute;
  left: 14px;
  bottom: 14px;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--paper);
  background: rgba(10, 10, 12, 0.74);
  border: 1px solid var(--bronze-line);
  border-radius: 3px;
  backdrop-filter: blur(6px);
}

.page-about .about-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 8px rgba(64, 224, 208, 0.8);
}

/* ---------- 主体两栏 ---------- */
.page-about .about-body {
  display: grid;
  gap: clamp(22px, 3.2vw, 40px);
  padding-block: clamp(34px, 4.6vw, 68px) clamp(46px, 6vw, 92px);
}

/* ---------- 章节索引栏 ---------- */
.page-about .about-rail {
  display: flex;
  gap: 6px;
  overflow-x: auto;
  padding: 8px 0;
  border-bottom: 1px solid var(--hair);
  scrollbar-width: none;
  -ms-overflow-style: none;
}

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

.page-about .about-rail-title {
  display: none;
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  color: rgba(169, 169, 178, 0.6);
}

.page-about .index-rail-link {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: baseline;
  gap: 7px;
  padding: 7px 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--smoke);
  text-decoration: none;
  border: 1px solid transparent;
  border-radius: 3px;
  transition: color 0.2s ease, background-color 0.2s ease, border-color 0.2s ease;
}

.page-about .index-rail-link:hover,
.page-about .index-rail-link:focus-visible {
  color: var(--gold);
  border-color: var(--bronze-line);
  outline: none;
}

.page-about .index-rail-link.is-current {
  color: var(--cyan);
  background: rgba(64, 224, 208, 0.07);
  border-color: rgba(64, 224, 208, 0.28);
}

.page-about .about-rail-num {
  font-size: 11px;
  color: var(--bronze);
}

.page-about .index-rail-link.is-current .about-rail-num {
  color: var(--cyan);
}

/* ---------- 章节通用 ---------- */
.page-about .about-chapter {
  position: relative;
  padding-block: clamp(30px, 4.2vw, 56px);
  border-top: 1px solid var(--hair);
  scroll-margin-top: calc(var(--header-h) + 28px);
}

.page-about .about-chapter:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .about-chapter-head {
  position: relative;
  margin-bottom: clamp(16px, 2.4vw, 28px);
}

.page-about .about-chapter-num {
  display: block;
  margin-bottom: 2px;
  font-family: var(--font-mono);
  font-size: clamp(42px, 7.6vw, 78px);
  font-weight: 700;
  line-height: 0.92;
  letter-spacing: 0.04em;
  color: rgba(183, 122, 61, 0.15);
  -webkit-text-stroke: 1px rgba(183, 122, 61, 0.42);
  pointer-events: none;
  user-select: none;
}

.page-about .about-chapter h2 {
  margin: 6px 0 0;
  font-family: var(--font-display);
  font-size: clamp(21px, 3.1vw, 33px);
  font-weight: 800;
  line-height: 1.28;
  letter-spacing: 0.015em;
  color: var(--paper);
  text-wrap: balance;
}

.page-about .about-prose p,
.page-about .about-chapter-lede {
  margin: 0 0 12px;
  max-width: 40em;
  font-size: 15.5px;
  line-height: 1.88;
  color: var(--smoke);
}

.page-about .about-lead {
  margin: 0 0 clamp(16px, 2.2vw, 22px);
  max-width: 40em;
  font-size: 15.5px;
  line-height: 1.88;
  color: rgba(243, 238, 228, 0.82);
}

/* ---------- 02 空间 ---------- */
.page-about .about-space-feature {
  position: relative;
  overflow: hidden;
  display: grid;
  gap: 16px;
  padding: clamp(18px, 2.6vw, 26px);
  margin-bottom: 16px;
  background: var(--about-card-bg);
  border: 1px solid var(--iron);
  border-radius: var(--radius);
}

.page-about .about-space-feature::after {
  content: "";
  position: absolute;
  right: -18%;
  bottom: -62%;
  width: 260px;
  height: 260px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(64, 224, 208, 0.16), transparent 70%);
  pointer-events: none;
}

.page-about .about-space-feature-body h3 {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 800;
  letter-spacing: 0.03em;
  color: var(--gold);
}

.page-about .about-space-feature-body p {
  margin: 0;
  max-width: 34em;
  font-size: 14px;
  line-height: 1.85;
  color: var(--smoke);
}

.page-about .about-space-facts {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 8px;
}

.page-about .about-space-facts li {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding-bottom: 8px;
  border-bottom: 1px dashed rgba(255, 255, 255, 0.08);
  font-size: 12.5px;
  color: var(--smoke);
}

.page-about .about-space-facts li:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}

.page-about .about-space-scroller {
  display: flex;
  gap: 14px;
  padding: 4px 0 14px;
  scroll-snap-type: x proximity;
  -webkit-overflow-scrolling: touch;
}

.page-about .about-space-card {
  flex: 0 0 min(78vw, 292px);
  scroll-snap-align: start;
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 20px 18px;
  background: var(--graphite);
  border: 1px solid var(--iron);
  border-radius: var(--radius);
  transition: border-color 0.25s ease, background-color 0.25s ease;
}

.page-about .about-space-card:hover {
  border-color: var(--bronze-soft);
  background: rgba(255, 255, 255, 0.025);
}

.page-about .about-space-count {
  font-family: var(--font-mono);
  font-size: 22px;
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--bronze);
}

.page-about .about-space-card .about-space-count {
  font-size: 17px;
}

.page-about .about-space-name {
  margin: 0;
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--paper);
}

.page-about .about-space-desc {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.75;
  color: var(--smoke);
}

.page-about .about-scroll-hint {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: rgba(169, 169, 178, 0.6);
}

/* ---------- 03 团队 ---------- */
.page-about .about-team {
  margin-top: 6px;
  border-top: 1px solid var(--hair);
}

.page-about .about-team .accordion-item {
  border-bottom: 1px solid var(--hair);
}

.page-about .about-team-head {
  margin: 0;
  font-size: inherit;
  font-weight: inherit;
  line-height: inherit;
}

.page-about .about-team-trigger {
  width: 100%;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 15px 2px;
  background: none;
  border: 0;
  font: inherit;
  text-align: left;
  color: var(--paper);
  cursor: pointer;
  transition: color 0.2s ease;
}

.page-about .about-team-trigger:hover {
  color: var(--gold);
}

.page-about .about-team-trigger:focus-visible {
  outline: 1px solid var(--bronze);
  outline-offset: 3px;
}

.page-about .about-team-trigger .accordion-index {
  min-width: 54px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--bronze);
}

.page-about .about-team-name {
  font-family: var(--font-display);
  font-size: 15.5px;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.page-about .about-team-tag {
  display: none;
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: rgba(169, 169, 178, 0.68);
}

.page-about .about-team .accordion-content {
  padding: 0 2px 16px;
}

.page-about .about-team .accordion-content p {
  margin: 0 0 8px;
  max-width: 38em;
  font-size: 14px;
  line-height: 1.85;
  color: var(--smoke);
}

.page-about .about-team .accordion-content p:last-child {
  margin-bottom: 0;
}

.page-about .about-steps {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  display: grid;
  gap: 12px;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
}

.page-about .about-step {
  padding: 2px 0 2px 12px;
  border-left: 1px solid var(--bronze-line);
}

.page-about .about-step-num {
  display: block;
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.14em;
  color: var(--bronze);
}

.page-about .about-step-name {
  display: block;
  margin-top: 4px;
  font-size: 14px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .about-step-desc {
  display: block;
  margin-top: 3px;
  font-size: 12.5px;
  line-height: 1.72;
  color: var(--smoke);
}

/* ---------- 04 会员 ---------- */
.page-about .about-tiers {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.page-about .about-tier {
  position: relative;
  overflow: hidden;
  padding: 18px 15px 16px;
  background: linear-gradient(170deg, rgba(20, 21, 25, 0.95), rgba(20, 21, 25, 0.5));
  border: 1px solid var(--iron);
  border-radius: var(--radius);
}

.page-about .about-tier::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--bronze), transparent 82%);
  opacity: 0.85;
}

.page-about .about-tier--top::before {
  background: linear-gradient(90deg, var(--cyan), transparent 82%);
}

.page-about .about-tier-name {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-size: 16.5px;
  font-weight: 800;
  letter-spacing: 0.08em;
  color: var(--gold);
}

.page-about .about-tier--top .about-tier-name {
  color: var(--cyan);
}

.page-about .about-tier-desc {
  margin: 0;
  font-size: 13px;
  line-height: 1.78;
  color: var(--smoke);
}

.page-about .about-return {
  display: grid;
  gap: 10px;
  margin-top: 18px;
  padding: clamp(16px, 2.4vw, 22px);
  border: 1px solid var(--bronze-line);
  border-radius: var(--radius);
  background: rgba(183, 122, 61, 0.045);
}

.page-about .about-return h3 {
  margin: 0;
  font-family: var(--font-display);
  font-size: 15.5px;
  font-weight: 800;
  letter-spacing: 0.04em;
  color: var(--paper);
}

.page-about .about-return-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 8px;
}

.page-about .about-return-list li {
  position: relative;
  padding-left: 18px;
  font-size: 13.5px;
  line-height: 1.82;
  color: var(--smoke);
}

.page-about .about-return-list li::before {
  content: "";
  position: absolute;
  left: 2px;
  top: 0.72em;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--cyan);
  opacity: 0.85;
}

/* ---------- 05 索引时间线 ---------- */
.page-about .about-index-layout {
  display: grid;
  gap: clamp(20px, 3vw, 34px);
}

.page-about .about-timeline {
  position: relative;
  padding-top: 2px;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 16px;
  bottom: 16px;
  width: 1px;
  background: linear-gradient(180deg, var(--bronze-soft), rgba(64, 224, 208, 0.5));
}

.page-about .about-node {
  position: relative;
  padding-left: 30px;
  border-bottom: 1px solid var(--hair);
}

.page-about .about-node:last-child {
  border-bottom: 0;
}

.page-about .about-node::before {
  content: "";
  position: absolute;
  left: 2px;
  top: 21px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--bronze);
  box-shadow: 0 0 0 3px rgba(183, 122, 61, 0.14);
}

.page-about .about-node--current::before {
  background: var(--cyan);
  box-shadow: 0 0 0 3px rgba(64, 224, 208, 0.16), 0 0 12px rgba(64, 224, 208, 0.6);
}

.page-about .about-node-head {
  margin: 0;
  font-size: inherit;
  font-weight: inherit;
  line-height: inherit;
}

.page-about .about-node-trigger {
  width: 100%;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px;
  padding: 16px 0;
  background: none;
  border: 0;
  font: inherit;
  text-align: left;
  color: var(--paper);
  cursor: pointer;
  transition: color 0.2s ease;
}

.page-about .about-node-trigger:hover {
  color: var(--gold);
}

.page-about .about-node-trigger:focus-visible {
  outline: 1px solid var(--bronze);
  outline-offset: 3px;
}

.page-about .about-node-year {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--bronze);
}

.page-about .about-node--current .about-node-year {
  color: var(--cyan);
}

.page-about .about-node-version {
  font-family: var(--font-mono);
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 0.03em;
}

.page-about .about-node-label {
  margin-left: auto;
  font-size: 12.5px;
  color: rgba(169, 169, 178, 0.78);
}

.page-about .about-node .accordion-content {
  padding: 0 0 16px;
}

.page-about .about-node .accordion-content p {
  margin: 0;
  max-width: 36em;
  font-size: 13.5px;
  line-height: 1.85;
  color: var(--smoke);
}

.page-about .about-index-figure {
  margin: 0;
  aspect-ratio: 9 / 7;
  overflow: hidden;
  border: 1px solid var(--bronze-line);
  border-radius: var(--radius);
  background: var(--graphite);
}

.page-about .about-index-figure img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(0.9) contrast(1.05) brightness(0.9);
}

.page-about .about-note {
  margin: clamp(16px, 2.4vw, 24px) 0 0;
  padding: 12px 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.8;
  letter-spacing: 0.02em;
  color: rgba(169, 169, 178, 0.88);
  border-left: 2px solid var(--bronze-line);
  border-radius: 0 var(--radius) var(--radius) 0;
  background: rgba(183, 122, 61, 0.05);
}

/* ---------- 06 城市 ---------- */
.page-about .about-city {
  display: grid;
  gap: clamp(18px, 3vw, 32px);
}

.page-about .about-city-figure {
  margin: 0;
  aspect-ratio: 11 / 8;
  overflow: hidden;
  border: 1px solid var(--iron);
  border-radius: var(--radius);
  background: var(--graphite);
}

.page-about .about-city-figure img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(0.95) contrast(1.05) brightness(0.92);
}

.page-about .about-city-body p {
  margin: 0 0 12px;
  max-width: 38em;
  font-size: 14.5px;
  line-height: 1.88;
  color: var(--smoke);
}

.page-about .about-city-stats {
  list-style: none;
  margin: 16px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .about-city-stats li {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding-top: 10px;
  border-top: 1px solid var(--hair);
}

.page-about .about-city-num {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: 19px;
  letter-spacing: 0.02em;
  color: var(--gold);
}

.page-about .about-city-txt {
  font-size: 13px;
  line-height: 1.72;
  color: var(--smoke);
}

/* ---------- 下一步 ---------- */
.page-about .about-next {
  padding-block: clamp(38px, 5.2vw, 78px);
  border-top: 1px solid var(--hair);
  background: linear-gradient(180deg, rgba(20, 21, 25, 0), rgba(20, 21, 25, 0.62));
}

.page-about .about-next h2 {
  margin: 0 0 clamp(18px, 2.6vw, 28px);
  font-family: var(--font-display);
  font-size: clamp(20px, 2.8vw, 28px);
  font-weight: 800;
  letter-spacing: 0.02em;
  color: var(--paper);
}

.page-about .about-next-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}

.page-about .about-next-card {
  display: flex;
  flex-direction: column;
  gap: 7px;
  padding: 18px 16px 20px;
  text-decoration: none;
  background: var(--graphite);
  border: 1px solid var(--iron);
  border-radius: var(--radius);
  transition: border-color 0.25s ease;
}

.page-about .about-next-card:hover,
.page-about .about-next-card:focus-visible {
  border-color: var(--bronze-soft);
  outline: none;
}

.page-about .about-next-kicker {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--bronze);
}

.page-about .about-next-title {
  font-size: 14.5px;
  line-height: 1.6;
  color: var(--paper);
}

.page-about .about-next-arrow {
  margin-top: 2px;
  font-family: var(--font-mono);
  font-size: 15px;
  color: rgba(169, 169, 178, 0.7);
  transition: color 0.25s ease, transform 0.25s ease;
}

.page-about .about-next-card:hover .about-next-arrow {
  color: var(--cyan);
  transform: translateX(3px);
}

/* ---------- 响应式 ---------- */
@media (min-width: 620px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-team-tag {
    display: inline;
  }
}

@media (min-width: 720px) {
  .page-about .about-space-feature {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    align-items: center;
  }

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

@media (min-width: 820px) {
  .page-about .about-city {
    grid-template-columns: minmax(0, 0.92fr) minmax(0, 1.08fr);
    align-items: center;
  }

  .page-about .about-index-layout {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    align-items: start;
  }

  .page-about .about-team .accordion-content {
    padding-left: 66px;
  }
}

@media (min-width: 860px) {
  .page-about .about-tiers {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 900px) {
  .page-about .about-hero-inner {
    grid-template-columns: minmax(0, 1.06fr) minmax(0, 0.94fr);
    gap: clamp(30px, 4vw, 60px);
  }
}

@media (min-width: 1024px) {
  .page-about .about-body {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: clamp(32px, 4vw, 62px);
    align-items: start;
  }

  .page-about .about-rail {
    position: sticky;
    top: calc(var(--header-h) + 26px);
    flex-direction: column;
    gap: 2px;
    overflow: visible;
    padding: 0 0 0 16px;
    border-bottom: 0;
    border-left: 1px solid var(--hair);
  }

  .page-about .about-rail-title {
    display: block;
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about .index-rail-link,
  .page-about .about-space-card,
  .page-about .about-team-trigger,
  .page-about .about-node-trigger,
  .page-about .about-next-card,
  .page-about .about-next-arrow {
    transition: none;
  }
}
<<<END>>>