.page-about {
  --about-rail-w: 132px;
  --about-sticky: calc(var(--hdr-lower) + 30px);
  position: relative;
  overflow-x: hidden;
  background: var(--c-ink);
  color: var(--c-text);
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  position: relative;
  padding: calc(var(--hdr-h) + clamp(18px, 3.4vw, 44px)) 0 clamp(30px, 4.4vw, 56px);
  background:
    radial-gradient(115% 72% at 84% -12%, rgba(47, 216, 198, 0.13), transparent 62%),
    radial-gradient(85% 62% at -6% 34%, rgba(240, 160, 60, 0.09), transparent 60%),
    linear-gradient(180deg, var(--c-night) 0%, var(--c-ink) 100%);
  border-bottom: 1px solid var(--c-scale);
}

.page-about .about-hero-grid {
  margin-top: clamp(18px, 2.8vw, 34px);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(22px, 3.4vw, 44px);
}

@media (min-width: 880px) {
  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    align-items: end;
  }
}

.page-about .about-hero-copy h1 {
  margin: 0.32em 0 0.5em;
  font-family: var(--f-display);
  font-weight: 200;
  font-size: clamp(2rem, 5.4vw, 4.05rem);
  line-height: 1.03;
  letter-spacing: 0.005em;
  color: var(--c-text);
  max-width: 22ch;
}

.page-about .about-hero-facts {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--c-scale);
  border: 1px solid var(--c-scale);
}

.page-about .about-hero-facts li {
  background: rgba(18, 48, 51, 0.6);
  padding: clamp(12px, 1.8vw, 20px) clamp(12px, 1.6vw, 18px);
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.page-about .about-hero-facts .fnum {
  font-family: var(--f-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(1.45rem, 2.8vw, 2.05rem);
  line-height: 1;
  color: var(--c-gold-soft);
}

.page-about .about-hero-facts .flabel {
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--c-dim);
}

.page-about .about-hero-media {
  margin: clamp(26px, 3.8vw, 48px) 0 0;
  line-height: 0;
  border: 1px solid var(--c-scale);
  background: var(--c-glass);
  overflow: hidden;
}

.page-about .about-hero-media img {
  display: block;
  width: 100%;
  height: clamp(180px, 30vw, 430px);
  object-fit: cover;
  object-position: center;
}

/* ---------- 阶段刻度总览 ---------- */

.page-about .about-overview {
  padding-block: clamp(42px, 6vw, 86px);
}

.page-about .about-scale {
  list-style: none;
  margin: clamp(24px, 3.2vw, 42px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--c-scale);
  border: 1px solid var(--c-scale);
}

@media (min-width: 760px) {
  .page-about .about-scale {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }
}

.page-about .about-scale-item {
  position: relative;
  background: var(--c-glass);
  padding: clamp(16px, 2.2vw, 24px) clamp(14px, 1.8vw, 20px);
  border-top: 3px solid var(--c-scale);
}

.page-about .about-scale-item[data-stage="s1"] { border-top-color: var(--c-gold); }
.page-about .about-scale-item[data-stage="s2"] { border-top-color: var(--c-red); }
.page-about .about-scale-item[data-stage="s3"] { border-top-color: var(--c-cyan); }
.page-about .about-scale-item[data-stage="s4"] { border-top-color: var(--c-green); }
.page-about .about-scale-item[data-stage="s5"] { border-top-color: var(--c-violet); }

.page-about .about-scale-num {
  display: block;
  font-family: var(--f-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--c-dim);
}

.page-about .about-scale-name {
  margin: 10px 0 8px;
  font-family: var(--f-display);
  font-weight: 400;
  font-size: clamp(1.05rem, 1.8vw, 1.32rem);
  line-height: 1.2;
  color: var(--c-text);
}

.page-about .about-scale-item p {
  margin: 0;
  font-size: 13px;
  line-height: 1.7;
  color: var(--c-dim);
}

.page-about .about-chart {
  margin: clamp(28px, 4vw, 50px) 0 0;
  padding: clamp(16px, 2.4vw, 28px);
  border: 1px solid var(--c-scale);
  background: rgba(18, 48, 51, 0.42);
}

.page-about .about-chart-svg {
  display: block;
  width: 100%;
  height: auto;
}

.page-about .about-chart-cap {
  margin: 14px 0 0;
  font-size: 12px;
  line-height: 1.65;
  letter-spacing: 0.02em;
  color: var(--c-dim);
}

/* ---------- 长卷：刻度轨 + 阶段 ---------- */

.page-about .about-lanes {
  padding-block: clamp(42px, 6vw, 88px);
  background: linear-gradient(180deg, var(--c-ink) 0%, var(--c-night) 52%, var(--c-ink) 100%);
  border-top: 1px solid var(--c-scale);
  border-bottom: 1px solid var(--c-scale);
}

.page-about .about-lanes-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(22px, 3vw, 38px);
  align-items: start;
}

@media (min-width: 960px) {
  .page-about .about-lanes-shell {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: clamp(32px, 4vw, 64px);
  }
}

.page-about .about-rail {
  display: flex;
  flex-direction: column;
  gap: 10px;
  min-width: 0;
}

@media (min-width: 960px) {
  .page-about .about-rail {
    position: sticky;
    top: var(--about-sticky);
  }
}

.page-about .about-rail-title {
  margin: 0;
  font-family: var(--f-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--c-dim);
}

.page-about .about-rail-nav {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding-bottom: 4px;
  scrollbar-width: none;
}

.page-about .about-rail-nav::-webkit-scrollbar {
  display: none;
}

@media (min-width: 960px) {
  .page-about .about-rail-nav {
    flex-direction: column;
    overflow: visible;
    padding-bottom: 0;
  }
}

.page-about .rail-link {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 56px;
  padding: 10px 12px;
  font-family: var(--f-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  text-decoration: none;
  color: var(--c-dim);
  background: rgba(18, 48, 51, 0.5);
  border: 1px solid var(--c-scale);
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease), background-color 0.18s var(--ease);
}

.page-about .rail-link:hover {
  color: var(--c-text);
  border-color: var(--c-cyan);
}

.page-about .rail-link:focus-visible {
  outline: 2px solid var(--c-cyan);
  outline-offset: 2px;
}

.page-about .rail-link.is-current {
  color: var(--c-mid);
  background: var(--c-cyan);
  border-color: var(--c-cyan);
}

.page-about .about-stages {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 3.6vw, 46px);
  min-width: 0;
}

.page-about .about-stage {
  position: relative;
  scroll-margin-top: calc(var(--hdr-lower) + 26px);
  padding: clamp(22px, 3vw, 34px) clamp(18px, 2.6vw, 32px);
  background:
    linear-gradient(142deg, rgba(255, 255, 255, 0.05), transparent 46%),
    var(--c-glass);
  border: 1px solid var(--c-scale);
  border-left: 3px solid var(--c-gold);
}

.page-about .about-stage[data-stage="s1"] { border-left-color: var(--c-gold); }
.page-about .about-stage[data-stage="s2"] { border-left-color: var(--c-red); }
.page-about .about-stage[data-stage="s3"] { border-left-color: var(--c-cyan); }
.page-about .about-stage[data-stage="s4"] { border-left-color: var(--c-green); }
.page-about .about-stage[data-stage="s5"] { border-left-color: var(--c-violet); }

.page-about .about-stage-head {
  display: flex;
  align-items: baseline;
  gap: clamp(12px, 2vw, 22px);
  margin-bottom: clamp(14px, 2vw, 22px);
  padding-bottom: clamp(12px, 1.8vw, 18px);
  border-bottom: 1px solid var(--c-scale);
}

.page-about .about-stage-index {
  flex: 0 0 auto;
  font-family: var(--f-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(2.1rem, 6vw, 3.8rem);
  line-height: 0.86;
  color: var(--c-gold-soft);
  opacity: 0.3;
}

.page-about .about-stage[data-stage="s2"] .about-stage-index { color: var(--c-red); opacity: 0.42; }
.page-about .about-stage[data-stage="s3"] .about-stage-index { color: var(--c-cyan); opacity: 0.42; }
.page-about .about-stage[data-stage="s4"] .about-stage-index { color: var(--c-green); opacity: 0.42; }
.page-about .about-stage[data-stage="s5"] .about-stage-index { color: var(--c-violet); opacity: 0.48; }

.page-about .about-stage-heading {
  min-width: 0;
}

.page-about .about-stage-heading .eyebrow {
  margin: 0;
}

.page-about .about-stage-title {
  margin: 6px 0 0;
  font-family: var(--f-display);
  font-weight: 300;
  font-size: clamp(1.32rem, 2.8vw, 1.95rem);
  line-height: 1.18;
  color: var(--c-text);
}

.page-about .about-stage-body p {
  margin: 0 0 1em;
  font-size: 15px;
  line-height: 1.78;
  color: var(--c-text);
  max-width: 68ch;
}

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

.page-about .about-stage-split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(16px, 2.4vw, 26px);
}

@media (min-width: 720px) {
  .page-about .about-stage-split {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr);
    align-items: start;
  }
}

.page-about .about-stage-media {
  margin: 0;
  line-height: 0;
  border: 1px solid var(--c-scale);
  background: var(--c-night);
  overflow: hidden;
}

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

.page-about .about-stage-facts {
  margin: clamp(18px, 2.4vw, 28px) 0 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--c-scale);
  border: 1px solid var(--c-scale);
}

@media (min-width: 620px) {
  .page-about .about-stage-facts {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

.page-about .about-stage-facts > div {
  background: var(--c-mid);
  padding: 12px 16px;
}

.page-about .about-stage-facts dt {
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--c-dim);
}

.page-about .about-stage-facts dd {
  margin: 7px 0 0;
  font-family: var(--f-mono);
  font-variant-numeric: tabular-nums;
  font-size: 1.28rem;
  line-height: 1;
  color: var(--c-gold-soft);
}

.page-about .about-role-list {
  list-style: none;
  margin: 0 0 1em;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--c-scale);
  border: 1px solid var(--c-scale);
}

@media (min-width: 620px) {
  .page-about .about-role-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

.page-about .about-role-list li {
  display: flex;
  flex-direction: column;
  gap: 5px;
  padding: 13px 16px;
  background: var(--c-mid);
}

.page-about .role-tag {
  font-family: var(--f-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--c-cyan);
}

.page-about .role-desc {
  font-size: 13.5px;
  line-height: 1.66;
  color: var(--c-dim);
}

.page-about .about-stage-more {
  margin-top: clamp(16px, 2.2vw, 24px);
  padding-top: clamp(12px, 1.8vw, 18px);
  border-top: 1px solid var(--c-scale);
}

.page-about .about-stage-more > summary {
  display: flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
  list-style: none;
  font-family: var(--f-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--c-cyan);
}

.page-about .about-stage-more > summary::-webkit-details-marker {
  display: none;
}

.page-about .about-stage-more > summary::before {
  content: "+";
  display: inline-block;
  width: 14px;
  font-size: 14px;
  line-height: 1;
}

.page-about .about-stage-more[open] > summary::before {
  content: "–";
}

.page-about .about-stage-more > summary:focus-visible {
  outline: 2px solid var(--c-cyan);
  outline-offset: 3px;
}

.page-about .about-stage-more-body {
  margin-top: 12px;
  max-width: 68ch;
}

.page-about .about-stage-more-body p {
  margin: 0 0 0.85em;
  font-size: 14px;
  line-height: 1.75;
  color: var(--c-dim);
}

.page-about .about-stage-more-body p:last-child {
  margin-bottom: 0;
}

.page-about .about-stage-copy {
  margin: clamp(16px, 2.2vw, 24px) 0 0;
}

/* ---------- 团队与质量口径 ---------- */

.page-about .about-team {
  padding-block: clamp(42px, 6vw, 88px);
}

.page-about .about-team-media {
  margin: clamp(24px, 3.4vw, 42px) 0 0;
  line-height: 0;
  border: 1px solid var(--c-scale);
  background: var(--c-glass);
  overflow: hidden;
}

.page-about .about-team-media img {
  display: block;
  width: 100%;
  height: clamp(190px, 32vw, 400px);
  object-fit: cover;
  object-position: center;
}

.page-about .about-team-grid {
  margin-top: clamp(24px, 3.4vw, 42px);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(22px, 3vw, 42px);
  align-items: start;
}

@media (min-width: 860px) {
  .page-about .about-team-grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 4fr);
  }
}

.page-about .about-team-roles {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--c-scale);
  border: 1px solid var(--c-scale);
}

.page-about .about-team-roles li {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  padding: 13px 18px;
  background: var(--c-ink);
}

.page-about .about-team-roles .role-name {
  font-size: 15px;
  color: var(--c-text);
}

.page-about .about-team-roles .role-num {
  font-family: var(--f-mono);
  font-variant-numeric: tabular-nums;
  font-size: 1.15rem;
  color: var(--c-cyan);
}

.page-about .about-team-total {
  margin: 16px 0 0;
  font-size: 13px;
  letter-spacing: 0.03em;
  color: var(--c-dim);
}

.page-about .about-team-total strong {
  font-family: var(--f-mono);
  font-weight: 400;
  font-size: 1.05rem;
  color: var(--c-gold-soft);
}

/* ---------- 继续核对 ---------- */

.page-about .about-next {
  padding-block: clamp(42px, 6vw, 88px);
}

.page-about .about-next-list {
  list-style: none;
  margin: clamp(24px, 3.2vw, 40px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--c-scale);
  border: 1px solid var(--c-scale);
}

@media (min-width: 720px) {
  .page-about .about-next-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 1060px) {
  .page-about .about-next-list {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

.page-about .about-next-list a {
  display: flex;
  flex-direction: column;
  gap: 8px;
  height: 100%;
  padding: clamp(18px, 2.4vw, 26px);
  background: var(--c-glass);
  text-decoration: none;
  border-top: 2px solid transparent;
  transition: background-color 0.18s var(--ease), border-color 0.18s var(--ease);
}

.page-about .about-next-list a:hover,
.page-about .about-next-list a:focus-visible {
  background: rgba(47, 216, 198, 0.08);
  border-top-color: var(--c-cyan);
}

.page-about .about-next-list a:focus-visible {
  outline: 2px solid var(--c-cyan);
  outline-offset: -2px;
}

.page-about .about-next-label {
  font-family: var(--f-display);
  font-weight: 400;
  font-size: 1.12rem;
  letter-spacing: 0.02em;
  color: var(--c-text);
}

.page-about .about-next-desc {
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--c-dim);
}

/* ---------- 减弱动态 ---------- */

@media (prefers-reduced-motion: reduce) {
  .page-about .rail-link,
  .page-about .about-next-list a {
    transition: none;
  }
}
<<<END>>>