.page-about {
  --rail-w: 196px;
  --line-gold: rgba(195, 154, 78, 0.34);
  --hair-soft: 1px solid rgba(18, 35, 58, 0.1);
  background: var(--paper);
  color: var(--text);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  background:
    radial-gradient(130% 140% at 88% -12%, rgba(30, 58, 92, 0.94) 0%, rgba(18, 35, 58, 1) 58%),
    var(--ink);
  color: var(--paper);
  padding: clamp(20px, 4vw, 34px) 0 clamp(36px, 6vw, 72px);
  overflow: hidden;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--gold) 22%, rgba(195, 154, 78, 0.18) 72%, transparent);
}

.page-about .about-hero .crumbs__link {
  color: rgba(245, 241, 232, 0.68);
}

.page-about .about-hero .crumbs__link:hover,
.page-about .about-hero .crumbs__link:focus-visible {
  color: var(--gold-soft);
}

.page-about .about-hero .crumbs__sep {
  color: rgba(195, 154, 78, 0.55);
}

.page-about .about-hero .crumbs__current {
  color: var(--gold-soft);
}

.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(24px, 4vw, 46px);
  margin-top: clamp(22px, 4vw, 38px);
}

.page-about .about-hero__title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(1.9rem, 5.4vw, 3.65rem);
  line-height: 1.18;
  letter-spacing: 0.02em;
  color: var(--paper-2);
  margin: 0.34em 0 0.52em;
  text-wrap: balance;
}

.page-about .about-hero .u-label {
  color: var(--gold-soft);
  margin: 0;
}

.page-about .about-hero__sub {
  font-family: var(--font-serif);
  font-size: clamp(0.98rem, 1.6vw, 1.125rem);
  line-height: 1.9;
  color: rgba(245, 241, 232, 0.78);
  max-width: 46ch;
  margin: 0;
}

.page-about .hero-meta {
  list-style: none;
  margin: 24px 0 0;
  padding: 16px 0 0;
  border-top: 1px solid rgba(195, 154, 78, 0.22);
  display: flex;
  flex-wrap: wrap;
  gap: 10px 26px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.05em;
  color: rgba(245, 241, 232, 0.6);
}

.page-about .hero-meta__k {
  color: var(--gold);
  margin-right: 6px;
}

/* 章节索引卡 */
.page-about .hero-index {
  border: 1px solid var(--line-gold);
  border-radius: var(--radius-m);
  background: rgba(30, 58, 92, 0.5);
  padding: 16px 18px 6px;
  align-self: start;
}

.page-about .hero-index__label {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.18em;
  color: var(--gold-soft);
  margin: 0 0 10px;
}

.page-about .hero-index__list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .hero-index__item + .hero-index__item {
  border-top: 1px solid rgba(195, 154, 78, 0.16);
}

.page-about .hero-index__link {
  display: flex;
  gap: 12px;
  align-items: baseline;
  padding: 11px 0;
  color: rgba(245, 241, 232, 0.86);
  text-decoration: none;
  font-size: 0.9375rem;
  line-height: 1.5;
  transition: color 180ms var(--ease), transform 180ms var(--ease);
}

.page-about .hero-index__link:hover,
.page-about .hero-index__link:focus-visible {
  color: var(--gold-soft);
  transform: translateX(3px);
}

.page-about .hero-index__no {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--gold);
  flex: none;
}

/* ---------- 首屏横幅 ---------- */
.page-about .about-banner {
  position: relative;
  margin: 0;
  aspect-ratio: 4 / 3;
  background: var(--ink-3);
  overflow: hidden;
}

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

.page-about .about-banner__cap {
  position: absolute;
  left: 0;
  bottom: 0;
  max-width: 100%;
  padding: 9px clamp(16px, 4vw, 44px);
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.1em;
  color: rgba(245, 241, 232, 0.8);
  background: linear-gradient(90deg, rgba(11, 24, 38, 0.88), rgba(11, 24, 38, 0));
}

/* ---------- 主体网格 ---------- */
.page-about .about-body {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(20px, 4vw, 52px);
  padding: clamp(30px, 5vw, 58px) 0 clamp(46px, 7vw, 92px);
}

/* 左侧导轨 */
.page-about .about-rail {
  display: none;
}

.page-about .about-rail__label {
  margin: 0;
  font-size: 0.6875rem;
  letter-spacing: 0.16em;
  color: var(--muted);
}

.page-about .about-rail__list {
  list-style: none;
  margin: 12px 0 0;
  padding: 0;
  border-left: 1px solid var(--line-gold);
}

.page-about .about-rail__link {
  display: block;
  padding: 9px 0 9px 14px;
  margin-left: -1px;
  border-left: 2px solid transparent;
  color: var(--muted);
  text-decoration: none;
  font-size: 0.875rem;
  line-height: 1.5;
  transition: color 180ms var(--ease), border-color 180ms var(--ease), background 180ms var(--ease);
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  color: var(--ink);
  border-left-color: var(--gold);
  background: rgba(195, 154, 78, 0.08);
}

/* 章节 */
.page-about .about-sections > section {
  scroll-margin-top: 92px;
  padding-top: clamp(26px, 4vw, 42px);
  margin-top: clamp(26px, 4vw, 42px);
  border-top: var(--hair-gold);
}

.page-about .about-sections > section:first-child {
  padding-top: 0;
  margin-top: 0;
  border-top: 0;
}

.page-about .about-h2 {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(1.35rem, 2.7vw, 1.85rem);
  line-height: 1.38;
  letter-spacing: 0.03em;
  color: var(--ink);
  margin: 0 0 0.72em;
}

.page-about .about-sections p {
  font-family: var(--font-serif);
  font-size: 1.0625rem;
  line-height: 1.9;
  color: var(--text);
  margin: 0 0 1.05em;
  max-width: 68ch;
}

.page-about .about-lead {
  color: var(--muted);
}

.page-about .aside-note {
  margin: 0 0 14px;
  padding-left: 14px;
  border-left: 2px solid var(--gold);
  font-family: var(--font-serif);
  font-size: 0.875rem;
  line-height: 1.75;
  letter-spacing: 0.01em;
  color: var(--gold-ink);
}

/* 引用块 */
.page-about .pull {
  margin: 26px 0;
  padding: 18px 22px;
  border-left: 3px solid var(--gold);
  border-radius: 0 var(--radius-m) var(--radius-m) 0;
  background: linear-gradient(100deg, rgba(30, 58, 92, 0.08), rgba(195, 154, 78, 0.12));
}

.page-about .about-sections .pull p {
  margin: 0;
  font-size: 1.0625rem;
  color: var(--ink);
  max-width: 52ch;
}

/* ---------- 时间轴 ---------- */
.page-about .tl {
  list-style: none;
  margin: 8px 0 0;
  padding: 0;
  position: relative;
}

.page-about .tl::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 14px;
  bottom: 14px;
  width: 1px;
  background: linear-gradient(180deg, var(--gold) 0%, rgba(195, 154, 78, 0.14) 100%);
}

.page-about .stage {
  position: relative;
  padding-left: 34px;
  margin-bottom: 26px;
}

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

.page-about .stage__dot {
  position: absolute;
  left: 0;
  top: 5px;
  width: 15px;
  height: 15px;
  border-radius: 50%;
  border: 1px solid var(--gold);
  background: radial-gradient(circle, var(--gold) 0 3px, var(--paper) 3.6px);
}

.page-about .stage__year {
  display: block;
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  color: var(--gold-ink);
  margin-bottom: 4px;
}

.page-about .stage__title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.0625rem;
  line-height: 1.5;
  letter-spacing: 0.02em;
  color: var(--ink);
  margin: 0 0 6px;
}

.page-about .about-sections .stage__text {
  font-size: 0.9688rem;
  line-height: 1.85;
  margin: 0;
  max-width: 62ch;
}

.page-about .about-sections .stage__note {
  margin: 0;
  max-height: 0;
  opacity: 0;
  overflow: hidden;
  padding-left: 12px;
  border-left: 1px dashed var(--line-gold);
  font-family: var(--font-serif);
  font-size: 0.875rem;
  line-height: 1.8;
  color: var(--muted);
  transition: max-height 220ms var(--ease), opacity 220ms var(--ease), margin-top 220ms var(--ease);
}

.page-about .stage:hover .stage__note,
.page-about .stage:focus .stage__note,
.page-about .stage:focus-within .stage__note {
  max-height: 12em;
  opacity: 1;
  margin-top: 10px;
}

/* ---------- 分栏 ---------- */
.page-about .split {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(20px, 3vw, 32px);
  margin-top: 18px;
}

/* ---------- 团队角色 ---------- */
.page-about .role-list {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
}

.page-about .role-list li {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 2px 16px;
  padding: 16px 0;
  border-top: var(--hair-soft);
}

.page-about .role-list li:last-child {
  border-bottom: var(--hair-soft);
}

.page-about .role-list__no {
  grid-row: 1 / span 2;
  padding-top: 3px;
  font-size: 0.8125rem;
  color: var(--gold);
}

.page-about .role-list h3 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1rem;
  letter-spacing: 0.02em;
  color: var(--ink);
}

.page-about .about-sections .role-list p {
  margin: 0;
  font-family: var(--font-serif);
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--muted);
  max-width: 52ch;
}

/* ---------- 步骤 ---------- */
.page-about .steps {
  list-style: none;
  counter-reset: stp;
  margin: 18px 0 22px;
  padding: 0;
}

.page-about .steps li {
  counter-increment: stp;
  position: relative;
  padding: 14px 0 14px 40px;
  border-top: var(--hair-soft);
  font-family: var(--font-serif);
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--text);
}

.page-about .steps li:last-child {
  border-bottom: var(--hair-soft);
}

.page-about .steps li::before {
  content: counter(stp, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 15px;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.05em;
  color: var(--gold);
}

/* ---------- 合作渠道 ---------- */
.page-about .coop {
  list-style: none;
  margin: 22px 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}

.page-about .coop li {
  padding: 18px 18px 20px;
  border: var(--hair-ink);
  border-radius: var(--radius-m);
  background: var(--paper-2);
  transition: transform 180ms var(--ease), border-color 180ms var(--ease), box-shadow 180ms var(--ease);
}

.page-about .coop li:hover {
  transform: translateY(-3px);
  border-color: rgba(195, 154, 78, 0.6);
  box-shadow: 0 12px 26px -20px rgba(18, 35, 58, 0.7);
}

.page-about .coop h3 {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1rem;
  letter-spacing: 0.02em;
  color: var(--ink);
}

.page-about .about-sections .coop p {
  margin: 0;
  font-family: var(--font-serif);
  font-size: 0.875rem;
  line-height: 1.8;
  color: var(--muted);
}

/* ---------- 结尾引导 ---------- */
.page-about .about-cta {
  position: relative;
  background: var(--ink);
  color: var(--paper);
  padding: clamp(40px, 6vw, 76px) 0;
}

.page-about .about-cta::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--gold) 30%, rgba(195, 154, 78, 0.15) 85%, transparent);
}

.page-about .about-cta .u-label {
  color: var(--gold-soft);
  margin: 0;
}

.page-about .about-cta h2 {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(1.35rem, 3vw, 1.9rem);
  line-height: 1.4;
  letter-spacing: 0.03em;
  color: var(--paper-2);
  margin: 0.42em 0 0.6em;
}

.page-about .about-cta p {
  font-family: var(--font-serif);
  font-size: 1rem;
  line-height: 1.9;
  color: rgba(245, 241, 232, 0.76);
  margin: 0;
  max-width: 54ch;
}

.page-about .about-cta__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(24px, 4vw, 44px);
  align-items: center;
}

.page-about .about-cta__links {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .about-cta__link {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 14px;
  padding: 14px 16px;
  border: 1px solid rgba(195, 154, 78, 0.32);
  border-radius: var(--radius-s);
  color: rgba(245, 241, 232, 0.9);
  text-decoration: none;
  font-size: 0.9375rem;
  line-height: 1.5;
  transition: background 180ms var(--ease), border-color 180ms var(--ease), color 180ms var(--ease);
}

.page-about .about-cta__link:hover,
.page-about .about-cta__link:focus-visible {
  background: rgba(195, 154, 78, 0.14);
  border-color: var(--gold);
  color: var(--gold-soft);
}

.page-about .about-cta__arrow {
  font-family: var(--font-mono);
  color: var(--gold);
  flex: none;
}

/* ---------- 窄屏兜底 ---------- */
@media (max-width: 420px) {
  .page-about .hero-meta {
    gap: 8px 18px;
    font-size: 0.6875rem;
  }

  .page-about .stage {
    padding-left: 28px;
  }

  .page-about .about-cta__link {
    font-size: 0.875rem;
    padding: 13px 14px;
  }
}

/* ---------- 平板及桌面 ---------- */
@media (min-width: 760px) {
  .page-about .about-banner {
    aspect-ratio: 16 / 7;
  }

  .page-about .coop {
    grid-template-columns: 1.15fr 1fr 0.85fr;
  }
}

@media (min-width: 920px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.55fr) minmax(250px, 0.7fr);
    align-items: end;
  }

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

  .page-about .about-rail {
    display: block;
    position: sticky;
    top: 96px;
  }

  .page-about .split {
    grid-template-columns: minmax(0, 1fr) minmax(240px, 300px);
    align-items: start;
  }

  .page-about .split--flip {
    grid-template-columns: minmax(240px, 300px) minmax(0, 1fr);
  }

  .page-about .about-cta__grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 0.92fr);
  }

  .page-about .about-sections > section {
    scroll-margin-top: 104px;
  }
}

@media (min-width: 1180px) {
  .page-about .about-hero__grid {
    gap: clamp(40px, 5vw, 72px);
  }

  .page-about .split {
    grid-template-columns: minmax(0, 1fr) 320px;
  }

  .page-about .split--flip {
    grid-template-columns: 320px minmax(0, 1fr);
  }
}
<<<END>>>