.page-about {
  --about-rail: 190px;
  --about-ink: #10131F;
  position: relative;
  isolation: isolate;
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding-block: 18px 12px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--mist);
  border-bottom: 1px dashed var(--line-steel);
}

.page-about .breadcrumb a {
  color: var(--mist);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

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

.page-about .breadcrumb__sep {
  color: var(--line-steel);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding-block: clamp(34px, 6vw, 78px) clamp(40px, 6vw, 82px);
  border-bottom: 1px solid var(--line-steel);
  background-image:
    linear-gradient(180deg, rgba(12, 23, 48, 0) 30%, rgba(12, 23, 48, .72) 100%),
    repeating-linear-gradient(90deg, rgba(35, 50, 90, .45) 0 1px, transparent 1px 92px);
}

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

.page-about .about-hero__copy .eyebrow {
  margin: 0 0 16px;
  color: var(--ember);
}

.page-about .about-hero h1 {
  margin: 0 0 20px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(30px, 5.4vw, 58px);
  line-height: 1.1;
  letter-spacing: .04em;
  color: var(--frost);
  max-width: 18ch;
}

.page-about .about-hero__lede {
  margin: 0 0 26px;
  max-width: 62ch;
  font-size: clamp(16px, 1.35vw, 18px);
  line-height: 1.85;
  color: var(--frost);
}

.page-about .about-hero__facts {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.page-about .about-hero__art {
  position: relative;
  margin: 0;
  padding: 10px;
  border: 1px solid var(--line-steel);
  background: var(--navy-deck);
}

.page-about .about-hero__art::after {
  content: "";
  position: absolute;
  right: -1px;
  bottom: -1px;
  width: 34px;
  height: 34px;
  border-right: 2px solid var(--signal);
  border-bottom: 2px solid var(--signal);
  pointer-events: none;
}

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

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.12fr) minmax(0, .88fr);
    gap: clamp(32px, 5vw, 72px);
  }
}

/* ---------- 分屏与索引轨 ---------- */
.page-about .page-about__split {
  display: grid;
  gap: clamp(28px, 4vw, 52px);
  padding-block: clamp(40px, 6vw, 78px);
}

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

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

.page-about .page-about__section {
  scroll-margin-top: calc(var(--header-h) + 24px);
}

.page-about .page-about__section + .page-about__section {
  margin-top: clamp(56px, 8vw, 104px);
  padding-top: clamp(40px, 5vw, 64px);
  border-top: 1px solid var(--line-steel);
}

@media (min-width: 1000px) {
  .page-about .page-about__split {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .page-about__rail {
    display: block;
    position: sticky;
    top: calc(var(--header-h) + 28px);
    padding-left: 24px;
  }

  .page-about .page-about__rail::before {
    content: "";
    position: absolute;
    left: 0;
    top: 2px;
    bottom: 2px;
    width: 8px;
    border-left: 1px solid var(--line-steel);
    background-image: repeating-linear-gradient(
      to bottom,
      var(--mist) 0 1px,
      transparent 1px 14px
    );
    opacity: .5;
  }
}

.page-about .rail-nav {
  display: flex;
  flex-direction: column;
  margin-top: 12px;
}

.page-about .rail-nav__link {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 7px 0;
  font-size: 13px;
  line-height: 1.45;
  color: var(--mist);
  text-decoration: none;
  transition: color var(--dur) var(--ease);
}

.page-about .rail-nav__link:hover,
.page-about .rail-nav__link:focus-visible,
.page-about .rail-nav__link.is-active {
  color: var(--cyan);
}

.page-about .rail-nav__num {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: .12em;
  color: var(--ember);
}

/* ---------- 章节头微调 ---------- */
.page-about .section-head__title {
  font-size: clamp(22px, 3.2vw, 34px);
  line-height: 1.22;
  max-width: 24ch;
}

/* ---------- 时间线 ---------- */
.page-about .about-timeline {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-timeline__item {
  display: grid;
  gap: 6px;
  padding-bottom: clamp(24px, 3vw, 36px);
}

.page-about .about-timeline__year {
  font-size: clamp(22px, 3vw, 30px);
  font-weight: 700;
  line-height: 1;
  color: var(--ember);
  letter-spacing: .04em;
}

.page-about .about-timeline__card {
  position: relative;
  padding-left: 20px;
  border-left: 1px solid var(--line-steel);
}

.page-about .about-timeline__card::before {
  content: "";
  position: absolute;
  left: -4px;
  top: 9px;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--ember);
  box-shadow: 0 0 0 3px rgba(217, 58, 33, .16);
}

.page-about .about-timeline__title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 17px;
  line-height: 1.5;
  letter-spacing: .02em;
  color: var(--frost);
}

.page-about .about-timeline__card p {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--mist);
}

@media (min-width: 720px) {
  .page-about .about-timeline__item {
    grid-template-columns: 88px minmax(0, 1fr);
    gap: 26px;
  }

  .page-about .about-timeline__year {
    padding-top: 4px;
    text-align: left;
  }
}

.page-about .page-about__figure {
  margin: clamp(24px, 3vw, 40px) 0 0;
  border: 1px solid var(--line-steel);
  background: var(--navy-deck);
  padding: 10px;
}

.page-about .page-about__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 14 / 9;
  object-fit: cover;
}

.page-about .page-about__figure figcaption {
  padding: 12px 4px 4px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--mist);
}

/* ---------- 团队 ---------- */
.page-about .about-team {
  display: grid;
  gap: clamp(24px, 3.4vw, 44px);
}

.page-about .about-roles {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line-steel);
  border: 1px solid var(--line-steel);
}

.page-about .about-roles__item {
  position: relative;
  padding: clamp(18px, 2.4vw, 26px);
  background: var(--navy-deck);
}

.page-about .about-roles__idx {
  display: block;
  font-size: 11px;
  letter-spacing: .2em;
  color: var(--ember);
  margin-bottom: 8px;
}

.page-about .about-roles__name {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 17px;
  letter-spacing: .02em;
  color: var(--frost);
}

.page-about .about-roles__item p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--mist);
}

.page-about .about-team__art {
  margin: 0;
  border: 1px solid var(--line-steel);
  padding: 10px;
  background: var(--navy-deck);
}

.page-about .about-team__art img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
}

.page-about .about-team__art figcaption {
  padding: 12px 4px 4px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--mist);
}

@media (min-width: 900px) {
  .page-about .about-team {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr);
    align-items: start;
  }
}

/* ---------- 数据能力 ---------- */
.page-about .about-metrics {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line-steel);
  border: 1px solid var(--line-steel);
}

.page-about .about-metrics__cell {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: clamp(16px, 2.2vw, 26px);
  background: var(--navy-deck);
}

.page-about .about-metrics__num {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: clamp(28px, 4vw, 44px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--frost);
  font-variant-numeric: tabular-nums;
  transform-origin: left center;
  transition: transform var(--dur) var(--ease), color var(--dur) var(--ease);
}

.page-about .about-metrics__suffix {
  font-size: .5em;
  margin-left: 3px;
  color: var(--cyan);
}

.page-about .about-metrics__unit {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--cyan);
}

.page-about .about-metrics__desc {
  margin: 6px 0 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--mist);
}

.page-about .about-metrics__cell:hover .about-metrics__num,
.page-about .about-metrics__cell:focus-within .about-metrics__num {
  transform: scale(1.05);
  color: var(--cyan);
}

@media (min-width: 760px) {
  .page-about .about-metrics {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-metrics__cell--wide {
    grid-column: span 2;
  }

  .page-about .about-metrics__cell--wide .about-metrics__num {
    font-size: clamp(40px, 5.4vw, 62px);
  }
}

.page-about .about-access {
  margin-top: clamp(28px, 3.6vw, 44px);
  border-top: 1px dashed var(--line-steel);
  padding-top: clamp(20px, 2.6vw, 30px);
}

.page-about .about-access__title {
  margin: 0 0 18px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 18px;
  letter-spacing: .03em;
  color: var(--frost);
}

.page-about .about-access__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: clamp(16px, 2vw, 24px);
}

.page-about .about-access__item {
  padding-left: 16px;
  border-left: 2px solid var(--teal-shadow);
}

.page-about .about-access__key {
  display: block;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 15px;
  letter-spacing: .04em;
  color: var(--cyan);
  margin-bottom: 6px;
}

.page-about .about-access__item p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--mist);
}

@media (min-width: 820px) {
  .page-about .about-access__list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

/* ---------- 会员体系 ---------- */
.page-about .about-intro {
  margin: 0 0 clamp(24px, 3vw, 36px);
  max-width: 70ch;
  font-size: 16.5px;
  line-height: 1.85;
  color: var(--frost);
}

.page-about .about-plans {
  display: grid;
  gap: 14px;
}

.page-about .about-plan {
  border: 1px solid var(--line-steel);
  background: var(--navy-deck);
}

.page-about .about-plan summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 16px 20px;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 16px;
  letter-spacing: .03em;
  color: var(--frost);
  transition: color var(--dur) var(--ease), background var(--dur) var(--ease);
}

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

.page-about .about-plan summary:hover,
.page-about .about-plan summary:focus-visible {
  color: var(--cyan);
}

.page-about .about-plan__hint {
  flex: none;
  width: 16px;
  height: 16px;
  position: relative;
}

.page-about .about-plan__hint::before,
.page-about .about-plan__hint::after {
  content: "";
  position: absolute;
  background: var(--cyan);
  transition: transform var(--dur) var(--ease), opacity var(--dur) var(--ease);
}

.page-about .about-plan__hint::before {
  left: 0;
  top: 7px;
  width: 16px;
  height: 2px;
}

.page-about .about-plan__hint::after {
  left: 7px;
  top: 0;
  width: 2px;
  height: 16px;
}

.page-about .about-plan[open] .about-plan__hint::after {
  transform: scaleY(0);
  opacity: 0;
}

.page-about .about-plan[open] summary {
  color: var(--cyan);
  border-bottom: 1px solid var(--line-steel);
}

.page-about .about-plan__body {
  padding: 18px 20px 22px;
}

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

.page-about .about-plan__list li {
  position: relative;
  padding-left: 20px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--mist);
}

.page-about .about-plan__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 12px;
  width: 10px;
  height: 1px;
  background: var(--cyan);
}

.page-about .about-membership__foot {
  margin: clamp(22px, 3vw, 32px) 0 0;
  max-width: 70ch;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--mist);
}

.page-about .about-membership__foot .link {
  color: var(--cyan);
}

@media (min-width: 880px) {
  .page-about .about-plans {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    align-items: start;
  }
}

/* ---------- 合作生态 ---------- */
.page-about .about-partners {
  display: grid;
  gap: clamp(16px, 2.2vw, 24px);
}

.page-about .about-partners__card {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.page-about .about-partners__num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(34px, 4.6vw, 52px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--signal);
  font-variant-numeric: tabular-nums;
}

.page-about .about-partners__card--local .about-partners__num {
  color: var(--ember);
}

.page-about .about-partners__note {
  margin: clamp(22px, 3vw, 32px) 0 0;
  max-width: 70ch;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--mist);
}

@media (min-width: 860px) {
  .page-about .about-partners {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-partners__card--local {
    grid-column: span 2;
  }
}

/* ---------- 服务节奏 ---------- */
.page-about .about-service {
  display: grid;
  gap: clamp(28px, 4vw, 48px);
}

.page-about .about-service__row {
  display: grid;
  gap: 6px;
  padding: 16px 0;
  border-bottom: 1px dashed var(--line-steel);
}

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

.page-about .about-service__time {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .1em;
  color: var(--cyan);
}

.page-about .about-service__row p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--mist);
}

.page-about .about-service__paper {
  align-self: start;
}

.page-about .about-service__paper-title {
  margin: 0 0 14px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(20px, 2.6vw, 26px);
  line-height: 1.3;
  letter-spacing: .03em;
  color: var(--cream-ink);
}

.page-about .about-service__paper p {
  margin: 0 0 14px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--cream-ink);
}

.page-about .about-service__paper .link {
  color: #0E6F6B;
  border-bottom-color: rgba(14, 111, 107, .4);
}

.page-about .about-service__paper .link:hover,
.page-about .about-service__paper .link:focus-visible {
  color: var(--ember);
  border-bottom-color: var(--ember);
}

.page-about .about-service__paper .btn {
  margin-top: 6px;
}

@media (min-width: 900px) {
  .page-about .about-service {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr);
    align-items: start;
  }

  .page-about .about-service__row {
    grid-template-columns: 150px minmax(0, 1fr);
    gap: 18px;
    align-items: baseline;
  }
}

/* ---------- 动效收敛 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .about-metrics__num,
  .page-about .about-plan summary,
  .page-about .rail-nav__link,
  .page-about .breadcrumb a {
    transition: none;
  }

  .page-about .about-metrics__cell:hover .about-metrics__num,
  .page-about .about-metrics__cell:focus-within .about-metrics__num {
    transform: none;
  }
}
<<<END>>>