.page-about {
  --pa-gap: clamp(20px, 3.2vw, 40px);
  --pa-block: clamp(56px, 8vw, 112px);
  --pa-tl-pad: clamp(20px, 3vw, 34px);
  --pa-shadow: 0 26px 64px -38px rgba(3, 10, 22, .95);
}

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

.page-about .ca-media {
  position: relative;
  overflow: hidden;
}

.page-about .ca-media--4x3 {
  aspect-ratio: 4 / 3;
}

.page-about .ca-media img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* ---------- 左侧坐标刻度 ---------- */
.page-about__rail {
  display: none;
}

.page-about__rail-num {
  font-family: var(--ca-font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--ca-ice);
  display: block;
  transition: color .18s var(--ca-ease);
}

.page-about__rail-label {
  font-size: 11px;
  letter-spacing: .06em;
  color: rgba(159, 178, 198, .62);
  display: block;
  margin-top: 2px;
}

.page-about .ca-rail__link {
  display: block;
  padding: 6px 8px;
  border-left: 2px solid transparent;
  text-decoration: none;
  transition: border-color .18s var(--ca-ease);
}

.page-about .ca-rail__link:hover,
.page-about .ca-rail__link[data-active],
.page-about .ca-rail__link[aria-current] {
  border-left-color: var(--ca-maple);
}

.page-about .ca-rail__link:hover .page-about__rail-num,
.page-about .ca-rail__link[data-active] .page-about__rail-num,
.page-about .ca-rail__link[aria-current] .page-about__rail-num {
  color: var(--ca-gold);
}

.page-about .ca-rail__link:hover .page-about__rail-label,
.page-about .ca-rail__link[data-active] .page-about__rail-label,
.page-about .ca-rail__link[aria-current] .page-about__rail-label {
  color: var(--ca-frost);
}

/* ---------- 首屏 ---------- */
.page-about__hero {
  position: relative;
  overflow: hidden;
  padding-block: clamp(28px, 4vw, 52px) clamp(52px, 8vw, 108px);
}

.page-about__hero::before {
  content: "";
  position: absolute;
  inset: 26% -14% 18% 40%;
  background:
    radial-gradient(58% 58% at 42% 40%, rgba(47, 180, 154, .17), transparent 72%),
    radial-gradient(52% 52% at 72% 78%, rgba(200, 50, 43, .14), transparent 74%);
  pointer-events: none;
}

.page-about__hero .ca-wrap {
  position: relative;
  z-index: 1;
}

.page-about__hero-grid {
  display: grid;
  gap: var(--pa-gap);
  margin-top: clamp(22px, 3vw, 40px);
  align-items: start;
}

.page-about__h1 {
  margin: 14px 0 0;
  font-family: var(--ca-font-display);
  font-weight: 900;
  font-size: clamp(37px, 8.2vw, 80px);
  line-height: 1.06;
  letter-spacing: -.02em;
  color: var(--ca-frost);
}

.page-about__lede {
  margin: clamp(16px, 2vw, 26px) 0 0;
  max-width: 46ch;
  font-size: clamp(16px, 1.7vw, 19px);
  line-height: 1.95;
  color: rgba(244, 247, 250, .8);
}

.page-about__hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(22px, 3vw, 34px);
}

.page-about__hero-fig {
  position: relative;
  margin: 0;
}

.page-about__hero-media {
  border: 1px solid rgba(217, 164, 65, .34);
  border-radius: 3px 24px 3px 24px;
  box-shadow: var(--pa-shadow);
}

.page-about__hero-fig::after {
  content: "";
  position: absolute;
  right: -8px;
  bottom: -8px;
  width: clamp(40px, 7vw, 70px);
  height: clamp(40px, 7vw, 70px);
  border-right: 2px solid var(--ca-gold);
  border-bottom: 2px solid var(--ca-gold);
  opacity: .55;
  pointer-events: none;
}

/* ---------- 01 为谁开门 ---------- */
.page-about__who {
  padding-block: var(--pa-block);
}

.page-about__dropcap > p:first-of-type::first-letter {
  float: left;
  font-family: var(--ca-font-display);
  font-weight: 900;
  font-size: 3.1em;
  line-height: .84;
  color: var(--ca-maple);
  margin: .1em .14em .02em 0;
}

.page-about__cases {
  border-top: 2px solid var(--ca-ink);
  padding-top: 18px;
}

.page-about__cases-title {
  margin: 0 0 6px;
  font-family: var(--ca-font-mono);
  font-size: 13px;
  font-weight: 500;
  letter-spacing: .08em;
  color: rgba(11, 27, 51, .66);
}

.page-about__case-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about__case {
  display: grid;
  gap: 9px;
  padding: 16px 0;
  border-bottom: 1px solid var(--ca-line-ink);
}

.page-about__case p {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.85;
  color: rgba(11, 27, 51, .82);
}

/* ---------- 02 双通道 ---------- */
.page-about__lanes {
  padding-block: var(--pa-block);
}

.page-about__lanes-grid {
  display: grid;
  gap: var(--pa-gap);
  margin-top: clamp(26px, 3.6vw, 48px);
}

.page-about__lane {
  border-left: 2px solid rgba(159, 178, 198, .28);
  padding: 2px 0 2px 20px;
}

.page-about__lane--main {
  border-left-color: var(--ca-aurora);
}

.page-about__lane--backup {
  border-left-color: var(--ca-gold);
}

.page-about__lane + .page-about__lane {
  margin-top: clamp(22px, 3vw, 32px);
}

.page-about__lane .ca-eyebrow {
  margin: 0 0 6px;
}

.page-about__lane-title {
  margin: 0 0 10px;
  font-family: var(--ca-font-display);
  font-size: clamp(19px, 2.3vw, 25px);
  font-weight: 700;
  line-height: 1.4;
  color: var(--ca-frost);
}

.page-about__lane p {
  margin: 0;
  font-size: 16px;
  line-height: 1.92;
  color: rgba(244, 247, 250, .78);
}

.page-about__lanes-visual {
  display: grid;
  gap: clamp(18px, 2.6vw, 28px);
}

.page-about__diagram-box {
  border: 1px solid var(--ca-line);
  border-radius: var(--ca-radius-sm);
  background: var(--ca-ink-2);
  padding: clamp(12px, 2vw, 20px);
}

.page-about__diagram {
  display: block;
  width: 100%;
  height: auto;
}

.page-about__diagram text {
  font-family: var(--ca-font-mono);
}

.page-about__lanes-fig {
  margin: 0;
}

.page-about__lanes-fig .ca-media {
  border: 1px solid var(--ca-line);
  border-radius: var(--ca-radius);
}

.page-about__stats {
  list-style: none;
  margin: clamp(30px, 4vw, 50px) 0 0;
  padding: 1px;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--ca-line);
  border: 1px solid var(--ca-line);
}

.page-about__stat {
  background: var(--ca-ink);
  padding: clamp(16px, 2vw, 22px) clamp(14px, 1.8vw, 20px);
  display: grid;
  gap: 6px;
}

.page-about__stat-num {
  font-family: var(--ca-font-mono);
  font-size: clamp(24px, 3vw, 34px);
  line-height: 1;
  color: var(--ca-gold);
  letter-spacing: .02em;
}

.page-about__stat-label {
  font-size: 13.5px;
  line-height: 1.6;
  color: var(--ca-ice);
}

/* ---------- 03 团队 ---------- */
.page-about__crew {
  padding-block: var(--pa-block);
}

.page-about__crew-top {
  display: grid;
  gap: var(--pa-gap);
  align-items: end;
}

.page-about__crew-fig {
  margin: 0;
}

.page-about__crew-fig .ca-media {
  border: 1px solid var(--ca-line-ink);
  border-radius: var(--ca-radius);
}

.page-about__crew-cards {
  display: grid;
  gap: 16px;
  margin-top: clamp(24px, 3vw, 38px);
}

.page-about__crew-card {
  display: flex;
  flex-direction: column;
  gap: 12px;
  background: var(--ca-paper);
  color: var(--ca-ink);
  border: 1px solid rgba(47, 180, 154, .5);
  border-radius: var(--ca-radius);
  padding: clamp(18px, 2.2vw, 26px);
}

.page-about__crew-num {
  width: 34px;
  height: 34px;
  display: inline-grid;
  place-items: center;
  font-family: var(--ca-font-mono);
  font-size: 15px;
  color: var(--ca-ink);
  border: 1px solid var(--ca-aurora);
  border-radius: var(--ca-radius-sm);
  transition: background .18s var(--ca-ease), color .18s var(--ca-ease), transform .18s var(--ca-ease);
}

.page-about__crew-card:hover .page-about__crew-num {
  background: var(--ca-maple);
  border-color: var(--ca-maple);
  color: #fff;
  transform: translateY(-2px);
}

.page-about__crew-title {
  margin: 0;
  font-family: var(--ca-font-display);
  font-size: clamp(18px, 2.1vw, 22px);
  font-weight: 700;
  color: var(--ca-ink);
}

.page-about__crew-card p {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.9;
  color: rgba(11, 27, 51, .82);
}

/* ---------- 04 时间线 ---------- */
.page-about__timeline-section {
  padding-block: var(--pa-block);
}

.page-about__timeline {
  list-style: none;
  margin: clamp(28px, 4vw, 50px) 0 0;
  padding: 0 0 0 var(--pa-tl-pad);
  border-left: 1px solid rgba(159, 178, 198, .26);
  display: grid;
  gap: clamp(26px, 3.4vw, 42px);
}

.page-about__tl-item {
  position: relative;
  padding-right: clamp(0px, 2vw, 24px);
}

.page-about__tl-item::before {
  content: "";
  position: absolute;
  left: calc(-1 * var(--pa-tl-pad) - 6px);
  top: 10px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--ca-ink);
  border: 2px solid var(--ca-gold);
  transition: background .18s var(--ca-ease), border-color .18s var(--ca-ease);
}

.page-about__tl-item:hover::before {
  background: var(--ca-maple);
  border-color: var(--ca-maple);
}

.page-about__tl-year {
  margin: 0;
  font-family: var(--ca-font-mono);
  font-size: clamp(20px, 2.6vw, 30px);
  letter-spacing: .06em;
  color: var(--ca-gold);
  line-height: 1.2;
}

.page-about__tl-title {
  margin: 8px 0 0;
  font-family: var(--ca-font-display);
  font-size: clamp(17px, 2vw, 21px);
  font-weight: 700;
  color: var(--ca-frost);
}

.page-about__tl-text {
  margin: 8px 0 0;
  max-width: 62ch;
  font-size: 15.5px;
  line-height: 1.92;
  color: rgba(244, 247, 250, .74);
}

.page-about__tl-more {
  margin-top: 12px;
  border-top: 1px dashed rgba(159, 178, 198, .24);
  padding-top: 10px;
  max-width: 62ch;
}

.page-about__tl-more summary {
  cursor: pointer;
  list-style: none;
  font-family: var(--ca-font-mono);
  font-size: 13px;
  letter-spacing: .06em;
  color: var(--ca-ice);
  transition: color .18s var(--ca-ease);
}

.page-about__tl-more summary::-webkit-details-marker {
  display: none;
}

.page-about__tl-more summary::before {
  content: "+ ";
  color: var(--ca-aurora);
}

.page-about__tl-more[open] summary::before {
  content: "− ";
}

.page-about__tl-more summary:hover,
.page-about__tl-more summary:focus-visible {
  color: var(--ca-frost);
}

.page-about__tl-more p {
  margin: 10px 0 0;
  font-size: 15px;
  line-height: 1.9;
  color: rgba(244, 247, 250, .68);
}

/* ---------- 05 长期价值 ---------- */
.page-about__keep {
  padding-block: var(--pa-block);
}

.page-about__reasons {
  list-style: none;
  margin: clamp(26px, 3.6vw, 46px) 0 0;
  padding: 0;
  display: grid;
  gap: 28px;
}

.page-about__reason {
  border-top: 2px solid var(--ca-maple);
  padding-top: 16px;
}

.page-about__reason h3 {
  margin: 0 0 8px;
  font-family: var(--ca-font-display);
  font-size: clamp(17px, 2vw, 21px);
  font-weight: 700;
  color: var(--ca-ink);
}

.page-about__reason p {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.92;
  color: rgba(11, 27, 51, .82);
}

.page-about__closing {
  margin-top: clamp(36px, 5vw, 64px);
  padding: clamp(24px, 3.4vw, 42px);
  background: var(--ca-ink);
  border-radius: var(--ca-radius);
  border: 1px solid rgba(217, 164, 65, .28);
}

.page-about__closing-text {
  margin: 0;
  max-width: 60ch;
  font-family: var(--ca-font-display);
  font-size: clamp(17px, 2.1vw, 23px);
  font-weight: 500;
  line-height: 1.85;
  color: var(--ca-frost);
}

.page-about__closing-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 16px 24px;
  margin-top: clamp(20px, 2.6vw, 30px);
}

.page-about__closing-link {
  color: var(--ca-frost);
  font-size: 15.5px;
  text-decoration: none;
  border-bottom: 1px solid var(--ca-maple);
  padding-bottom: 2px;
  transition: color .18s var(--ca-ease), border-color .18s var(--ca-ease);
}

.page-about__closing-link:hover,
.page-about__closing-link:focus-visible {
  color: var(--ca-gold);
  border-bottom-color: var(--ca-gold);
}

/* ---------- 响应式 ---------- */
@media (min-width: 700px) {
  .page-about__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

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

  .page-about__reasons {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 26px;
  }
}

@media (min-width: 900px) {
  .page-about__hero-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: clamp(32px, 4.5vw, 64px);
  }

  .page-about__crew-top {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: clamp(32px, 4vw, 56px);
  }
}

@media (min-width: 960px) {
  .page-about__lanes-grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    align-items: start;
    gap: clamp(32px, 4vw, 60px);
  }
}

@media (min-width: 1240px) {
  .page-about__rail {
    display: flex;
    flex-direction: column;
    gap: 10px;
    position: fixed;
    left: clamp(10px, 2vw, 26px);
    top: 50%;
    transform: translateY(-50%);
    z-index: 30;
    margin: 0;
    padding: 0;
    list-style: none;
  }

  .page-about__hero .ca-wrap,
  .page-about__who .ca-wrap,
  .page-about__lanes .ca-wrap,
  .page-about__crew .ca-wrap,
  .page-about__timeline-section .ca-wrap,
  .page-about__keep .ca-wrap {
    max-width: var(--ca-wrap);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about__crew-num,
  .page-about__tl-item::before,
  .page-about .ca-rail__link {
    transition: none;
  }
}
<<<END>>>