.page-about {
  --about-rail: 112px;
  --about-gap: clamp(24px, 4vw, 48px);
  --about-line: rgba(122, 90, 46, .16);
  display: block;
  overflow-x: clip;
  color: var(--text-body);
  background:
    radial-gradient(120% 55% at 108% 0%, rgba(15, 58, 95, .55) 0%, rgba(14, 17, 22, 0) 62%),
    radial-gradient(90% 40% at -10% 42%, rgba(178, 74, 34, .16) 0%, rgba(14, 17, 22, 0) 60%),
    var(--ink-900);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  display: grid;
  gap: clamp(24px, 4vw, 44px);
  padding-top: clamp(26px, 5vw, 56px);
  padding-bottom: clamp(32px, 6vw, 68px);
}

.page-about .about-hero__kicker {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  margin: 0 0 18px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--ochre-300);
}

.page-about .about-hero__kicker::before {
  content: "";
  width: 36px;
  height: 1px;
  background: var(--ochre-600);
}

.page-about .about-hero h1 {
  margin: 0;
  max-width: 20ch;
  font-family: var(--font-heading);
  font-weight: 900;
  font-size: clamp(30px, 5.6vw, 56px);
  line-height: 1.14;
  letter-spacing: -.02em;
  color: var(--text-strong);
}

.page-about .about-hero__lede {
  margin: 22px 0 0;
  max-width: 58ch;
  font-size: clamp(16px, 1.9vw, 18px);
  line-height: 1.8;
  color: var(--text-body);
}

.page-about .about-hero__stats {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  margin: 30px 0 0;
  padding: 0;
  list-style: none;
  background: var(--about-line);
  border: 1px solid var(--about-line);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.page-about .about-hero__stats li {
  padding: 14px 14px 16px;
  background: var(--ink-900);
}

.page-about .about-hero__stats .num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(22px, 3.4vw, 30px);
  line-height: 1.05;
  color: var(--yellow-400);
}

.page-about .about-hero__stats small {
  display: block;
  margin-top: 7px;
  font-size: 12px;
  letter-spacing: .05em;
  line-height: 1.5;
  color: var(--text-dim);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.page-about .about-hero__media {
  margin: 0;
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--about-line);
}

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

/* ---------- 长卷与刻度尺 ---------- */
.page-about .about-canvas {
  padding-bottom: clamp(48px, 8vw, 96px);
}

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

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

.page-about .about-section {
  padding-block: clamp(34px, 6vw, 72px);
  border-top: 1px solid var(--about-line);
}

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

.page-about .about-section__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px 18px;
  margin-bottom: 14px;
}

.page-about .about-section__num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--ochre-300);
}

.page-about .about-section h2 {
  margin: 0 0 clamp(16px, 2.6vw, 26px);
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: clamp(23px, 3.3vw, 35px);
  line-height: 1.24;
  letter-spacing: -.02em;
  color: var(--text-strong);
}

.page-about .about-section .prose {
  max-width: 66ch;
}

.page-about .about-section .prose p {
  margin: 0 0 14px;
  line-height: 1.8;
}

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

/* ---------- 起点 ---------- */
.page-about .about-origin {
  display: grid;
  gap: 18px;
  margin-bottom: clamp(22px, 3.4vw, 34px);
}

.page-about .about-origin__year {
  display: block;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(46px, 9vw, 82px);
  line-height: .88;
  letter-spacing: -.04em;
  color: var(--ochre-600);
}

.page-about .about-quote {
  margin: 0;
  padding: 16px 20px 16px 22px;
  border-left: 4px solid var(--ochre-600);
  background: linear-gradient(90deg, rgba(178, 74, 34, .16), rgba(178, 74, 34, 0));
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

.page-about .about-quote p {
  margin: 0;
  font-family: var(--font-heading);
  font-size: clamp(18px, 2.6vw, 22px);
  line-height: 1.5;
  color: var(--text-strong);
}

.page-about .about-quote cite {
  display: block;
  margin-top: 8px;
  font-family: var(--font-mono);
  font-style: normal;
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--text-dim);
}

/* ---------- 时间轴分段切换 ---------- */
.page-about .about-timeline {
  margin-top: clamp(20px, 3vw, 30px);
  padding-top: 4px;
}

.page-about .about-timeline .tabs__list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: clamp(20px, 3vw, 28px);
}

.page-about .about-timeline .tabs__tab {
  appearance: none;
  cursor: pointer;
  padding: 10px 18px;
  border: 1px solid var(--line-gold);
  border-radius: var(--radius-pill);
  background: transparent;
  color: var(--text-body);
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .05em;
  transition: background var(--dur) var(--ease), color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-timeline .tabs__tab:hover {
  border-color: var(--ochre-300);
  color: var(--text-strong);
}

.page-about .about-timeline .tabs__tab[aria-selected="true"] {
  background: var(--yellow-400);
  border-color: var(--yellow-400);
  color: var(--ink-900);
}

.page-about .about-timeline .tabs__tab:focus-visible {
  outline: 2px solid var(--sea-400);
  outline-offset: 3px;
}

.page-about .about-step {
  display: grid;
  grid-template-columns: 40px minmax(0, 1fr);
  column-gap: 14px;
  row-gap: 7px;
  align-items: start;
  padding: 16px 0;
  border-top: 1px solid var(--about-line);
}

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

.page-about .about-step__n {
  grid-column: 1;
  grid-row: 1 / span 2;
  padding-top: 3px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .06em;
  color: var(--ochre-300);
}

.page-about .about-step__what {
  grid-column: 2;
  margin: 0;
  line-height: 1.72;
  color: var(--text-strong);
}

.page-about .about-step__gain {
  grid-column: 2;
  margin: 0;
  padding-left: 12px;
  border-left: 2px solid var(--sea-700);
  font-size: 14px;
  line-height: 1.75;
  color: var(--text-dim);
}

.page-about .about-timeline__figure {
  margin-top: clamp(22px, 3.4vw, 34px);
}

/* ---------- 恒定导航 ---------- */
.page-about .about-index {
  display: grid;
  gap: clamp(18px, 3vw, 32px);
  margin-top: clamp(20px, 3vw, 30px);
}

.page-about .about-index__grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
  background: var(--about-line);
  border: 1px solid var(--about-line);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.page-about .about-index__item {
  background: var(--ink-900);
}

.page-about .about-index__item a {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 15px 14px;
  font-size: 14px;
  color: var(--text-body);
  text-decoration: none;
  transition: background var(--dur) var(--ease), color var(--dur) var(--ease);
}

.page-about .about-index__item a:hover,
.page-about .about-index__item a:focus-visible {
  background: var(--ink-700);
  color: var(--yellow-400);
}

.page-about .about-index__n {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--ochre-300);
}

.page-about .about-index__aside {
  padding: 22px 20px;
  border: 1px dashed var(--line-gold);
  border-radius: var(--radius-md);
  background: linear-gradient(180deg, rgba(15, 58, 95, .42) 0%, rgba(15, 58, 95, 0) 100%);
}

.page-about .about-index__big {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: clamp(40px, 7vw, 60px);
  line-height: 1;
  color: var(--yellow-400);
}

.page-about .about-index__aside p {
  margin: 0 0 12px;
  font-size: 14px;
  line-height: 1.75;
  color: var(--text-body);
}

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

/* ---------- 团队 ---------- */
.page-about .about-team {
  display: grid;
  gap: clamp(20px, 3vw, 34px);
  margin-top: clamp(20px, 3vw, 30px);
}

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

.page-about .about-team__card {
  padding: 20px 20px 22px;
  border-radius: var(--radius-md);
}

.page-about .about-team__num {
  display: inline-block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--yellow-400);
}

.page-about .about-team__card h3 {
  margin: 0 0 9px;
  font-family: var(--font-heading);
  font-size: 19px;
  line-height: 1.35;
  color: var(--text-strong);
}

.page-about .about-team__card p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: rgba(243, 237, 227, .8);
}

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

/* ---------- 覆盖规模 ---------- */
.page-about .about-scale {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(22px, 3.4vw, 32px) 0 0;
  padding: 0;
  list-style: none;
  background: var(--about-line);
  border-top: 1px solid var(--about-line);
  border-bottom: 1px solid var(--about-line);
}

.page-about .about-scale li {
  padding: 20px 16px 22px;
  background: var(--ink-900);
}

.page-about .about-scale__n {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(28px, 4.6vw, 40px);
  line-height: 1;
  color: var(--turquoise-400);
}

.page-about .about-scale__l {
  display: block;
  margin-top: 10px;
  font-size: 13.5px;
  line-height: 1.65;
  color: var(--text-dim);
}

/* ---------- 三件事 ---------- */
.page-about .about-principles {
  display: grid;
  gap: 14px;
  margin: clamp(20px, 3vw, 30px) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-principles__item {
  padding: 20px 20px 22px;
  border-left: 4px solid var(--ochre-600);
  border-radius: var(--radius-sm);
  background: var(--ink-700);
}

.page-about .about-principles__item:nth-child(2) {
  border-left-color: var(--sea-400);
}

.page-about .about-principles__item:nth-child(3) {
  border-left-color: var(--yellow-400);
}

.page-about .about-principles__item h3 {
  margin: 0 0 10px;
  font-family: var(--font-heading);
  font-size: 19px;
  line-height: 1.3;
  color: var(--text-strong);
}

.page-about .about-principles__item p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--text-body);
}

.page-about .about-principles__item .about-principles__proof {
  margin-top: 14px;
  padding-top: 12px;
  border-top: 1px solid rgba(122, 90, 46, .34);
  font-family: var(--font-mono);
  font-size: 12.5px;
  line-height: 1.6;
  letter-spacing: .02em;
  color: var(--sea-400);
}

/* ---------- 收尾入口 ---------- */
.page-about .about-cta {
  margin-top: clamp(34px, 6vw, 72px);
  padding: clamp(24px, 4vw, 44px);
  border: 1px solid var(--line-gold);
  border-radius: var(--radius-lg);
  background:
    linear-gradient(135deg, rgba(178, 74, 34, .22) 0%, rgba(15, 58, 95, .34) 100%),
    var(--ink-700);
}

.page-about .about-cta h2 {
  margin: 0 0 12px;
  font-family: var(--font-heading);
  font-size: clamp(22px, 3.2vw, 30px);
  line-height: 1.3;
  letter-spacing: -.02em;
  color: var(--text-strong);
}

.page-about .about-cta p {
  margin: 0;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--text-body);
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 22px;
}

/* ---------- 折点 ---------- */
@media (min-width: 560px) {
  .page-about .about-index__grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

@media (min-width: 720px) {
  .page-about .about-origin {
    grid-template-columns: auto minmax(0, 1fr);
    column-gap: clamp(22px, 4vw, 44px);
    align-items: start;
  }
}

@media (min-width: 860px) {
  .page-about .about-index {
    grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr);
    column-gap: clamp(24px, 4vw, 52px);
    align-items: start;
  }

  .page-about .about-principles {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 16px;
  }

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

@media (min-width: 900px) {
  .page-about .about-hero {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    column-gap: clamp(30px, 5vw, 72px);
    align-items: end;
  }

  .page-about .about-team {
    grid-template-columns: minmax(0, 1.55fr) minmax(0, 1fr);
    column-gap: clamp(24px, 4vw, 48px);
    align-items: start;
  }
}

@media (min-width: 1024px) {
  .page-about .about-canvas {
    display: grid;
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    column-gap: var(--about-gap);
    align-items: start;
  }

  .page-about .about-rail {
    display: block;
    align-self: stretch;
    border-right: 1px solid var(--about-line);
  }

  .page-about .about-rail__track {
    position: sticky;
    top: calc(var(--header-h) + 34px);
    display: flex;
    flex-direction: column;
    gap: 30px;
    padding-block: 10px;
  }

  .page-about .about-rail__tick {
    display: flex;
    align-items: center;
    gap: 12px;
    font-family: var(--font-mono);
    font-size: 12px;
    letter-spacing: .1em;
    white-space: nowrap;
    color: var(--text-dim);
  }

  .page-about .about-rail__tick::after {
    content: "";
    flex: 1;
    height: 1px;
    background: linear-gradient(90deg, var(--line-gold) 0%, rgba(122, 90, 46, 0) 100%);
  }

  .page-about .about-rail__tick--now {
    color: var(--yellow-400);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-timeline .tabs__tab,
  .page-about .about-index__item a {
    transition: none;
  }
}
<<<END>>>