.page-about {
  background: var(--sand);
  color: var(--ink);
}

.page-about img {
  max-width: 100%;
  height: auto;
  display: block;
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  position: relative;
  background: var(--deep-sea);
  color: var(--sand);
  padding: clamp(20px, 3vw, 34px) 0 clamp(32px, 5vw, 64px);
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: linear-gradient(to right, rgba(232, 238, 240, 0.055) 1px, transparent 1px);
  background-size: 88px 100%;
  pointer-events: none;
}

.page-about .about-hero .wrap {
  position: relative;
}

.page-about .about-hero .breadcrumbs {
  color: var(--reef-soft);
  margin-bottom: clamp(22px, 4vw, 44px);
}

.page-about .about-hero .breadcrumbs a {
  color: var(--sand);
  text-decoration: none;
}

.page-about .about-hero .breadcrumbs a:hover,
.page-about .about-hero .breadcrumbs a:focus-visible {
  color: var(--coral);
}

.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(18px, 3vw, 32px);
}

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

.page-about .about-rot {
  writing-mode: vertical-rl;
  transform: rotate(180deg);
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  color: var(--gold);
}

.page-about .about-hero__note {
  margin: 0;
  font-size: 13px;
  line-height: 1.8;
  color: var(--reef-soft);
  max-width: 22em;
}

.page-about .about-hero__main .overline {
  color: var(--coral);
  margin: 0;
}

.page-about .about-hero h1 {
  margin: 14px 0 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(32px, 6.4vw, 66px);
  line-height: 1.08;
  letter-spacing: -0.02em;
  color: var(--sand);
  max-width: 15em;
}

.page-about .about-hero .lead {
  margin: clamp(16px, 2.4vw, 26px) 0 0;
  max-width: 34em;
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.85;
  color: rgba(244, 239, 230, 0.84);
}

.page-about .about-stats {
  margin-top: clamp(28px, 4vw, 46px);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line-dark);
  border: 1px solid var(--line-dark);
}

.page-about .about-stat {
  background: var(--deep-sea);
  padding: clamp(14px, 2vw, 20px);
}

.page-about .about-stat .num {
  display: block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(24px, 3.4vw, 36px);
  line-height: 1;
  color: var(--sand);
}

.page-about .about-stat__k {
  display: block;
  margin-top: 9px;
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--reef-soft);
}

/* ---------- 主体骨架 ---------- */

.page-about .about-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(18px, 3vw, 40px);
  padding-top: clamp(26px, 5vw, 54px);
  padding-bottom: clamp(36px, 6vw, 72px);
}

.page-about .about-rail__list {
  display: flex;
  gap: 8px;
  list-style: none;
  margin: 0;
  padding: 0 0 8px;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.page-about .about-rail__link {
  display: flex;
  align-items: center;
  gap: 8px;
  min-height: 44px;
  padding: 8px 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--paper);
  color: var(--deep-sea);
  text-decoration: none;
  font-size: 13px;
  white-space: nowrap;
  transition: background 0.18s ease, border-color 0.18s ease, color 0.18s ease;
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  border-color: var(--coral);
  background: var(--coral-soft);
  color: var(--coral-deep);
}

.page-about .about-rail__no {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--reef);
}

/* ---------- 章节 ---------- */

.page-about .chapter {
  padding: clamp(30px, 5vw, 58px) 0;
  border-top: 1px solid var(--line);
  scroll-margin-top: 120px;
}

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

.page-about .chapter__head {
  display: flex;
  align-items: baseline;
  gap: 14px;
  margin-bottom: clamp(14px, 2.2vw, 22px);
}

.page-about .chapter__no {
  position: relative;
  flex: none;
  padding-left: 34px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--coral);
}

.page-about .chapter__no::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.6em;
  width: 24px;
  height: 2px;
  background: var(--coral);
}

.page-about .chapter__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(22px, 3.6vw, 36px);
  line-height: 1.22;
  letter-spacing: -0.01em;
  color: var(--deep-sea);
  text-wrap: balance;
}

.page-about .chapter__lede {
  margin: 0 0 clamp(20px, 3vw, 32px);
  padding-left: clamp(14px, 2vw, 22px);
  border-left: 3px solid var(--coral);
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(20px, 3.1vw, 32px);
  line-height: 1.38;
  letter-spacing: -0.01em;
  color: var(--moss);
  max-width: 22em;
}

.page-about .chapter__split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(18px, 3vw, 32px);
  align-items: start;
}

.page-about .chapter__text p {
  margin: 0 0 1.1em;
  max-width: 34em;
  font-size: 16px;
  line-height: 1.85;
  color: var(--ink);
}

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

/* ---------- 图片 ---------- */

.page-about .about-shot {
  margin: 0;
  position: relative;
  overflow: hidden;
  aspect-ratio: 4 / 3;
  background: var(--night);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  box-shadow: var(--shell);
}

.page-about .about-shot img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.page-about .about-shot--abstract {
  aspect-ratio: 1 / 1;
}

.page-about .about-banner {
  margin: 0 0 clamp(22px, 3.4vw, 38px);
  aspect-ratio: 3 / 2;
}

/* ---------- 四道工序 ---------- */

.page-about .steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.page-about .step {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--paper);
  transition: border-color 0.18s ease;
}

.page-about .step:hover {
  border-color: var(--line-strong);
}

.page-about .step summary {
  display: flex;
  align-items: center;
  gap: 12px;
  min-height: 44px;
  padding: 13px 16px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .step summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 18px;
  line-height: 1;
  color: var(--coral);
}

.page-about .step details[open] summary::after {
  content: "–";
}

.page-about .step__no {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--reef);
}

.page-about .step__name {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 16px;
  color: var(--deep-sea);
}

.page-about .step__meta {
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--reef);
}

.page-about .step__body {
  padding: 0 16px 16px;
  border-top: 1px dashed var(--line);
}

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

/* ---------- 时间线 ---------- */

.page-about .timeline {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 12px;
  bottom: 14px;
  width: 1px;
  background: var(--line-strong);
}

.page-about .timeline__item {
  position: relative;
  padding: 0 0 clamp(20px, 2.8vw, 28px) 34px;
}

.page-about .timeline__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 5px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--gold);
  box-shadow: 0 0 0 4px var(--sand);
  transition: transform 0.2s ease;
}

.page-about .timeline__item:hover::before {
  transform: scale(1.35);
}

.page-about .timeline__item--now::before {
  background: var(--coral);
}

.page-about .timeline__year {
  display: block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 14px;
  letter-spacing: 0.1em;
  color: var(--gold);
}

.page-about .timeline__item--now .timeline__year {
  color: var(--coral);
}

.page-about .timeline__title {
  margin: 6px 0 6px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 17px;
  color: var(--deep-sea);
}

.page-about .timeline__note {
  margin: 0;
  max-width: 36em;
  font-size: 15px;
  line-height: 1.82;
  color: var(--ink);
}

/* ---------- 团队 ---------- */

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

.page-about .crew__item {
  background: var(--paper);
  padding: clamp(16px, 2.4vw, 24px);
}

.page-about .crew__top {
  display: flex;
  align-items: baseline;
  gap: 12px;
}

.page-about .crew__num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(26px, 3.4vw, 34px);
  line-height: 1;
  color: var(--moss);
}

.page-about .crew__role {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 17px;
  color: var(--deep-sea);
}

.page-about .crew__desc {
  margin: 12px 0 16px;
  max-width: 36em;
  font-size: 15px;
  line-height: 1.82;
  color: var(--ink);
}

.page-about .crew__bar {
  height: 6px;
  background: var(--mist);
  overflow: hidden;
}

.page-about .crew__bar span {
  display: block;
  height: 100%;
  background: var(--moss);
}

.page-about .crew__item:nth-child(1) .crew__bar span {
  width: 48%;
}

.page-about .crew__item:nth-child(2) .crew__bar span {
  width: 30%;
}

.page-about .crew__item:nth-child(3) .crew__bar span {
  width: 22%;
}

.page-about .about-fineprint {
  margin: clamp(16px, 2.4vw, 22px) 0 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--reef);
  max-width: 40em;
}

/* ---------- 合作与资质 ---------- */

.page-about .partners {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(16px, 2.6vw, 28px);
}

.page-about .partner {
  border-left: 2px solid var(--moss);
  padding-left: clamp(14px, 2vw, 20px);
}

.page-about .partner__num {
  display: block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(26px, 3.2vw, 34px);
  line-height: 1;
  color: var(--coral);
}

.page-about .partner__name {
  margin: 8px 0 8px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 18px;
  color: var(--deep-sea);
}

.page-about .partner p {
  margin: 0;
  max-width: 32em;
  font-size: 15px;
  line-height: 1.82;
  color: var(--ink);
}

.page-about .credential {
  list-style: none;
  margin: clamp(22px, 3vw, 32px) 0 0;
  padding: clamp(16px, 2.4vw, 22px) 0 0;
  border-top: 1px solid var(--line);
  display: grid;
  gap: 12px;
}

.page-about .credential li {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 15px;
  line-height: 1.7;
  color: var(--ink);
}

.page-about .credential__dot {
  flex: none;
  width: 8px;
  height: 8px;
  margin-top: 0.62em;
  background: var(--gold);
  transform: rotate(45deg);
}

/* ---------- 准则 ---------- */

.page-about .creed {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 3vw, 30px);
}

.page-about .creed__item {
  position: relative;
  padding-top: 22px;
  border-top: 2px solid var(--deep-sea);
}

.page-about .creed__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: -2px;
  width: 38px;
  height: 2px;
  background: var(--coral);
}

.page-about .creed__no {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.24em;
  color: var(--reef);
}

.page-about .creed__title {
  margin: 10px 0 10px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 21px;
  letter-spacing: -0.01em;
  color: var(--deep-sea);
}

.page-about .creed__item p {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--ink);
}

/* ---------- 尾段 ---------- */

.page-about .about-cta {
  background: var(--night);
  color: var(--sand);
  padding: clamp(34px, 6vw, 68px) 0;
}

.page-about .about-cta h2 {
  margin: 0 0 14px;
  max-width: 20em;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(23px, 3.6vw, 36px);
  line-height: 1.24;
  letter-spacing: -0.01em;
  color: var(--sand);
}

.page-about .about-cta p {
  margin: 0 0 24px;
  max-width: 38em;
  font-size: 16px;
  line-height: 1.82;
  color: rgba(244, 239, 230, 0.8);
}

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

.page-about .about-cta__note {
  margin: 22px 0 0;
  font-size: 13px;
  line-height: 1.8;
  color: var(--reef-soft);
}

.page-about .about-cta__note a {
  color: var(--coral);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .about-cta__note a:hover,
.page-about .about-cta__note a:focus-visible {
  color: var(--sand);
}

.page-about .about-top {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 44px;
  margin-top: 18px;
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--sand);
  text-decoration: none;
  border-bottom: 1px solid var(--line-dark);
}

.page-about .about-top:hover,
.page-about .about-top:focus-visible {
  color: var(--coral);
  border-bottom-color: var(--coral);
}

/* ---------- 断点 ---------- */

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

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

@media (min-width: 760px) {
  .page-about .chapter__split {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  }

  .page-about .chapter__split--rev {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
  }

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

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 4fr) minmax(0, 8fr);
    gap: clamp(24px, 3vw, 48px);
  }

  .page-about .about-hero__aside {
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    gap: 26px;
    padding-right: clamp(16px, 2vw, 28px);
    border-right: 1px solid var(--line-dark);
  }
}

@media (min-width: 980px) {
  .page-about .about-shell {
    grid-template-columns: 168px minmax(0, 1fr);
    gap: clamp(28px, 4vw, 62px);
  }

  .page-about .about-rail {
    position: sticky;
    top: 96px;
    align-self: start;
  }

  .page-about .about-rail__list {
    flex-direction: column;
    gap: 0;
    padding-bottom: 0;
    overflow: visible;
    border-left: 1px solid var(--line);
  }

  .page-about .about-rail__link {
    min-height: 44px;
    padding: 10px 0 10px 14px;
    border: 0;
    border-left: 2px solid transparent;
    border-radius: 0;
    background: transparent;
    margin-left: -1px;
    font-size: 13px;
  }

  .page-about .about-rail__link:hover,
  .page-about .about-rail__link:focus-visible {
    background: transparent;
    border-left-color: var(--coral);
    color: var(--coral-deep);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .step,
  .page-about .about-rail__link,
  .page-about .timeline__item::before {
    transition: none;
  }

  .page-about .timeline__item:hover::before {
    transform: none;
  }
}
<<<END>>>