.page-about {
  --about-rail-w: 78px;
  --about-gap: clamp(20px, 4vw, 72px);
  --about-ch-pad: clamp(0px, 3vw, 46px);
  --about-space: clamp(52px, 8vw, 104px);
  background: var(--ink);
  color: var(--paper);
  padding-bottom: clamp(48px, 8vw, 112px);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding: clamp(26px, 5vw, 56px) 0 clamp(40px, 6vw, 76px);
  border-bottom: 1px solid var(--line);
}

.page-about .about-hero .crumbs {
  margin: 0 0 clamp(22px, 3vw, 38px);
}

.page-about .about-hero__kicker {
  color: var(--lime);
  margin: 0;
}

.page-about .about-hero__title {
  font-size: clamp(34px, 6.4vw, 78px);
  line-height: 1.05;
  letter-spacing: -0.015em;
  margin: 16px 0 0;
  max-width: 16em;
}

.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(28px, 4vw, 52px);
  margin-top: clamp(28px, 4vw, 52px);
  align-items: start;
}

.page-about .about-hero__quote {
  font-family: var(--font-serif);
  font-size: clamp(19px, 2.3vw, 24px);
  line-height: 1.68;
  margin: 0 0 24px;
  padding-left: 18px;
  border-left: 3px solid var(--lime);
  max-width: 24em;
}

.page-about .about-hero__copy {
  font-size: 17px;
  line-height: 1.78;
  color: var(--mist);
  max-width: 34em;
  margin: 0 0 18px;
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

.page-about .about-hero__fig {
  width: 100%;
}

/* ---------- 主体两栏 ---------- */
.page-about .about-body {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
}

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

.page-about .about-flow {
  min-width: 0;
  padding-top: clamp(36px, 6vw, 72px);
}

.page-about .about-ch {
  padding-bottom: var(--about-space);
  position: relative;
}

.page-about .about-ch:last-of-type {
  padding-bottom: clamp(32px, 5vw, 56px);
}

/* ---------- 章节头 ---------- */
.page-about .about-ch__head {
  display: flex;
  align-items: stretch;
  gap: clamp(12px, 2vw, 22px);
  padding-bottom: 16px;
  border-bottom: 1px solid var(--line);
  margin-bottom: clamp(22px, 3vw, 36px);
}

.page-about .about-ch__num {
  flex: none;
  writing-mode: vertical-rl;
  text-orientation: upright;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  line-height: 1;
  color: var(--lime);
  padding-top: 3px;
}

.page-about .about-ch__title {
  font-size: clamp(23px, 3.6vw, 42px);
  line-height: 1.16;
  letter-spacing: -0.01em;
  margin: 0;
  max-width: 20em;
}

.page-about .about-ch__lead {
  font-family: var(--font-serif);
  font-size: clamp(17px, 2.1vw, 22px);
  line-height: 1.72;
  margin: 0 0 clamp(24px, 3vw, 36px);
  padding-left: 16px;
  border-left: 2px solid var(--lime);
  max-width: 26em;
}

/* ---------- 01 统计 ---------- */
.page-about .about-stats {
  margin-bottom: 26px;
}

.page-about .about-stat {
  border-top: 1px solid var(--line);
  padding-top: 16px;
}

.page-about .about-stat__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(38px, 5.8vw, 62px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--lime);
}

.page-about .about-stat__label {
  display: block;
  margin: 10px 0 12px;
  color: var(--mist);
}

.page-about .about-stat__text {
  font-size: 15px;
  line-height: 1.75;
  color: var(--mist);
  margin: 0;
  max-width: 30em;
}

.page-about .about-note {
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.9;
  letter-spacing: 0.02em;
  color: var(--mist);
  margin: 0;
  padding-left: 16px;
  position: relative;
}

.page-about .about-note::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.85em;
  width: 9px;
  height: 1px;
  background: var(--mist);
}

.page-about .about-inline-link {
  color: var(--data-blue);
  text-decoration: none;
  border-bottom: 1px solid currentColor;
}

.page-about .about-inline-link:hover {
  color: var(--lime);
}

/* ---------- 02 时间轴 ---------- */
.page-about .about-timeline {
  list-style: none;
  margin: 0 0 26px;
  padding: 0 0 0 26px;
  position: relative;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 3px;
  top: 10px;
  bottom: 10px;
  width: 1px;
  background: var(--line);
}

.page-about .about-timeline__item {
  position: relative;
  padding-bottom: clamp(26px, 3.6vw, 42px);
}

.page-about .about-timeline__item:last-child {
  padding-bottom: 0;
}

.page-about .about-timeline__dot {
  position: absolute;
  left: -26px;
  top: 8px;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--lime);
}

.page-about .about-timeline__ver {
  display: inline-block;
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--lime);
  border: 1px solid var(--line);
  padding: 3px 9px;
  margin-bottom: 10px;
}

.page-about .about-timeline__title {
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 700;
  letter-spacing: 0.01em;
  margin: 0 0 8px;
  color: var(--paper);
}

.page-about .about-timeline__text {
  font-size: 15px;
  line-height: 1.75;
  color: var(--mist);
  margin: 0;
  max-width: 36em;
}

.page-about .about-fold {
  margin-top: 12px;
  border-top: 1px solid var(--line);
  max-width: 36em;
}

.page-about .about-fold__summary {
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 11px 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--mist);
  transition: color 240ms var(--ease);
}

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

.page-about .about-fold__summary::before {
  content: "+";
  font-size: 15px;
  line-height: 1;
  color: var(--lime);
}

.page-about .about-fold[open] .about-fold__summary {
  color: var(--paper);
}

.page-about .about-fold[open] .about-fold__summary::before {
  content: "−";
}

.page-about .about-fold__body {
  padding: 0 0 8px;
}

.page-about .about-fold__body p {
  font-size: 15px;
  line-height: 1.78;
  color: var(--mist);
  margin: 0;
}

/* ---------- 03 流程 ---------- */
.page-about .about-pipeline {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(24px, 3.5vw, 44px);
  margin-bottom: clamp(24px, 3vw, 38px);
}

.page-about .about-pipeline__fig {
  width: 100%;
  aspect-ratio: 3 / 2;
}

.page-about .about-steps {
  list-style: none;
  margin: 0;
  padding: 0;
  counter-reset: none;
}

.page-about .about-steps__item {
  padding: 0 0 20px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 20px;
}

.page-about .about-steps__item:last-child {
  padding-bottom: 0;
  border-bottom: 0;
  margin-bottom: 0;
}

.page-about .about-steps__num {
  display: inline-block;
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--data-blue);
  margin-bottom: 8px;
}

.page-about .about-steps__title {
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 700;
  margin: 0 0 6px;
  color: var(--paper);
}

.page-about .about-steps__item p {
  font-size: 15px;
  line-height: 1.75;
  color: var(--mist);
  margin: 0;
  max-width: 34em;
}

.page-about .about-metrics {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 0 0 18px;
  padding: 0;
  background: var(--line);
}

.page-about .about-metrics__item {
  background: var(--ink);
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 10px;
  padding: 14px 16px;
}

.page-about .about-metrics__k {
  color: var(--mist);
}

.page-about .about-metrics__v {
  font-size: 22px;
  color: var(--lime);
  line-height: 1;
}

/* ---------- 04 团队 ---------- */
.page-about .about-team {
  margin-bottom: 24px;
}

.page-about .about-team__row {
  display: grid;
  grid-template-columns: 64px minmax(0, 1fr);
  gap: clamp(14px, 2.5vw, 30px);
  align-items: start;
  padding: clamp(18px, 2.4vw, 28px) 0;
  border-top: 1px solid var(--line);
}

.page-about .about-team__row:last-child {
  border-bottom: 1px solid var(--line);
}

.page-about .about-team__num {
  font-size: clamp(34px, 5vw, 54px);
  line-height: 0.9;
  letter-spacing: -0.03em;
  color: transparent;
  -webkit-text-stroke: 1px var(--lime);
  text-stroke: 1px var(--lime);
}

.page-about .about-team__role {
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 700;
  margin: 0 0 8px;
  color: var(--paper);
}

.page-about .about-team__txt p {
  font-size: 15px;
  line-height: 1.78;
  color: var(--mist);
  margin: 0;
  max-width: 34em;
}

/* ---------- 05 伙伴 ---------- */
.page-about .about-partners {
  list-style: none;
  margin: 0 0 24px;
  padding: 0;
}

.page-about .about-partners__item {
  display: grid;
  grid-template-columns: 72px minmax(0, 1fr);
  gap: clamp(14px, 2.4vw, 28px);
  align-items: start;
  padding: clamp(18px, 2.4vw, 26px) 0;
  border-top: 1px solid rgba(244, 247, 242, 0.14);
}

.page-about .about-partners__item:last-child {
  border-bottom: 1px solid rgba(244, 247, 242, 0.14);
}

.page-about .about-partners__num {
  font-size: clamp(24px, 3.4vw, 36px);
  line-height: 1;
  color: var(--warn);
  letter-spacing: -0.02em;
}

.page-about .about-partners__title {
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 700;
  margin: 0 0 7px;
  color: var(--paper);
}

.page-about .about-partners__item p {
  font-size: 15px;
  line-height: 1.76;
  color: var(--mist);
  margin: 0;
  max-width: 34em;
}

/* ---------- 06 长期跟队 ---------- */
.page-about .about-longterm {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(24px, 3.5vw, 44px);
  align-items: start;
}

.page-about .about-longterm__fig {
  width: 100%;
  aspect-ratio: 4 / 5;
}

.page-about .about-longterm__copy {
  font-size: 16px;
  line-height: 1.8;
  color: var(--paper);
  margin: 0 0 clamp(20px, 3vw, 30px);
  max-width: 32em;
}

.page-about .about-perks {
  list-style: none;
  margin: 0 0 clamp(22px, 3vw, 30px);
  padding: 0;
}

.page-about .about-perks__item {
  padding: 0 0 16px 18px;
  border-bottom: 1px solid rgba(244, 247, 242, 0.12);
  margin-bottom: 16px;
  position: relative;
}

.page-about .about-perks__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.7em;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--lime);
}

.page-about .about-perks__item:last-child {
  border-bottom: 0;
  margin-bottom: 0;
  padding-bottom: 0;
}

.page-about .about-perks__title {
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 700;
  margin: 0 0 6px;
  color: var(--paper);
}

.page-about .about-perks__item p {
  font-size: 15px;
  line-height: 1.76;
  color: var(--mist);
  margin: 0;
  max-width: 32em;
}

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

/* ---------- 收尾 ---------- */
.page-about .about-cta {
  border-top: 1px solid var(--line);
  padding-top: clamp(30px, 4vw, 48px);
}

.page-about .about-cta__title {
  font-size: clamp(24px, 3.6vw, 40px);
  line-height: 1.18;
  margin: 0 0 16px;
  max-width: 18em;
}

.page-about .about-cta__text {
  font-size: 16px;
  line-height: 1.8;
  color: var(--mist);
  margin: 0 0 26px;
  max-width: 36em;
}

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

/* ---------- 色块画板 ---------- */
.page-about .about-ch--moss {
  --line: #31452f;
  background: var(--moss);
  border-radius: var(--radius-soft);
  padding: clamp(24px, 4vw, 46px);
  margin-bottom: var(--about-space);
}

.page-about .about-ch--moss.about-ch {
  padding-bottom: clamp(24px, 4vw, 46px);
}

.page-about .about-ch--slate {
  background: var(--panel);
  border-radius: var(--radius-soft);
  padding: clamp(24px, 4vw, 46px);
  margin-bottom: var(--about-space);
}

.page-about .about-ch--slate.about-ch {
  padding-bottom: clamp(24px, 4vw, 46px);
}

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

/* ---------- 桌面 ---------- */
@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: 7fr 5fr;
  }

  .page-about .about-body {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: var(--about-gap);
  }

  .page-about .about-rail {
    display: block;
    position: sticky;
    top: 96px;
    align-self: start;
    padding-top: clamp(40px, 6vw, 76px);
  }

  .page-about .about-rail__list {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    flex-direction: column;
    gap: 18px;
    border-left: 1px solid var(--line);
    padding-left: 12px;
  }

  .page-about .about-rail__link {
    display: flex;
    align-items: center;
    gap: 8px;
    text-decoration: none;
    color: var(--mist);
    transition: color 240ms var(--ease);
  }

  .page-about .about-rail__bar {
    display: block;
    width: 2px;
    height: 14px;
    background: var(--line);
    transition: background 240ms var(--ease);
  }

  .page-about .about-rail__txt {
    font-family: var(--font-mono);
    font-size: 12px;
    letter-spacing: 0.1em;
  }

  .page-about .about-rail__link:hover {
    color: var(--paper);
  }

  .page-about .about-rail__link[aria-current="true"] {
    color: var(--lime);
  }

  .page-about .about-rail__link[aria-current="true"] .about-rail__bar {
    background: var(--lime);
  }

  .page-about .about-pipeline {
    grid-template-columns: 5fr 7fr;
    align-items: start;
  }

  .page-about .about-longterm {
    grid-template-columns: 5fr 7fr;
  }

  .page-about .about-team__row {
    grid-template-columns: 108px minmax(0, 1fr);
  }
}

@media (min-width: 1100px) {
  .page-about .about-pipeline__fig {
    position: sticky;
    top: 96px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-rail__link,
  .page-about .about-rail__bar,
  .page-about .about-fold__summary,
  .page-about .about-inline-link {
    transition: none;
  }
}
<<<END>>>