.page-about {
  --ab-line: rgba(203, 195, 180, .55);
  background: var(--paper);
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  position: relative;
  background: linear-gradient(180deg, var(--indigo-900) 0%, var(--indigo-800) 62%, var(--indigo-600) 100%);
  color: var(--on-deep);
  overflow: hidden;
}
.page-about .ab-hero::after {
  content: "";
  position: absolute;
  inset: auto 0 0 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--gold), transparent);
  opacity: .55;
}
.page-about .ab-hero__inner {
  position: relative;
  padding: clamp(30px, 5vw, 58px) 0 clamp(46px, 7vw, 88px);
}
.page-about .ab-hero .crumbs__link,
.page-about .ab-hero .crumbs__current { color: var(--on-deep-dim); }
.page-about .ab-hero .crumbs__link:hover { color: var(--gold); }
.page-about .ab-hero .eyebrow { color: var(--sky); }
.page-about .ab-hero__title {
  margin: 18px 0 0;
  color: #fff;
  font-weight: 200;
  font-size: clamp(34px, 6.2vw, 76px);
  line-height: 1.14;
  letter-spacing: -.01em;
}
.page-about .ab-hero__lede {
  margin: 24px 0 0;
  max-width: 62ch;
  color: var(--on-deep);
  opacity: .9;
}
.page-about .ab-hero__facts {
  margin-top: clamp(34px, 5vw, 62px);
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: rgba(159, 190, 207, .26);
  border-top: 1px solid rgba(159, 190, 207, .26);
  border-bottom: 1px solid rgba(159, 190, 207, .26);
}
.page-about .ab-fact {
  background: var(--indigo-900);
  padding: 20px 18px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.page-about .ab-fact__num {
  font-family: var(--font-num);
  font-size: clamp(34px, 5vw, 48px);
  line-height: 1;
  color: var(--gold);
  letter-spacing: -.02em;
}
.page-about .ab-fact__unit {
  font-size: .42em;
  margin-left: 4px;
  letter-spacing: .04em;
}
.page-about .ab-fact__label {
  font-size: 13px;
  line-height: 1.7;
  color: var(--on-deep-dim);
  letter-spacing: .04em;
}

/* ---------- 年份刻度栏 + 叙事画布 ---------- */
.page-about .ab-body {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
  padding: 0 0 clamp(60px, 9vw, 120px);
}
.page-about .ab-rail {
  position: relative;
  padding: 28px 0 6px;
  border-bottom: 1px solid var(--ab-line);
}
.page-about .ab-rail__label {
  margin: 0 0 14px;
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--muted);
}
.page-about .ab-rail__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 10px 22px;
}
.page-about .ab-rail__link {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  text-decoration: none;
  color: var(--ink);
  border-bottom: 1px solid transparent;
  padding-bottom: 2px;
  transition: border-color .25s var(--ease), color .25s var(--ease);
}
.page-about .ab-rail__link:hover,
.page-about .ab-rail__link:focus-visible {
  border-bottom-color: var(--gold);
  color: var(--indigo-800);
}
.page-about .ab-rail__year {
  font-family: var(--font-num);
  font-size: 18px;
  color: var(--indigo-800);
}
.page-about .ab-rail__note {
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--muted);
}
.page-about .ab-rail__foot {
  margin: 16px 0 0;
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--muted);
}

.page-about .ab-canvas { min-width: 0; }
.page-about .ab-sec {
  position: relative;
  padding: clamp(44px, 7vw, 92px) 0 0;
}
.page-about .ab-sec .eyebrow { color: var(--indigo-600); }
.page-about .ab-sec .section-title {
  margin: 12px 0 0;
  color: var(--indigo-900);
  max-width: 30ch;
  line-height: 1.3;
}
.page-about .ab-prose { margin-top: 20px; }
.page-about .ab-sec .prose p + p { margin-top: 1.1em; }
.page-about .ab-link {
  color: var(--indigo-800);
  text-decoration: none;
  border-bottom: 1px solid var(--gold);
  padding-bottom: 1px;
  transition: color .22s var(--ease), border-color .22s var(--ease);
}
.page-about .ab-link:hover,
.page-about .ab-link:focus-visible {
  color: var(--gold);
  border-bottom-color: var(--indigo-800);
}

/* ---------- 三类支持 ---------- */
.page-about .ab-uses {
  list-style: none;
  margin: clamp(30px, 4vw, 46px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
  border-top: 1px solid var(--ab-line);
}
.page-about .ab-use {
  padding: 24px 0;
  border-bottom: 1px solid var(--ab-line);
  display: grid;
  grid-template-columns: 44px 1fr;
  gap: 6px 16px;
  align-items: start;
}
.page-about .ab-use__num {
  font-family: var(--font-num);
  font-size: 15px;
  line-height: 1.9;
  color: var(--gold);
  letter-spacing: .1em;
}
.page-about .ab-use__title {
  margin: 0;
  font-size: 19px;
  font-weight: 600;
  color: var(--indigo-900);
  grid-column: 2;
}
.page-about .ab-use p {
  grid-column: 2;
  margin: 6px 0 0;
  color: var(--muted);
  font-size: 15.5px;
  line-height: 1.85;
}

/* ---------- 场景切换 ---------- */
.page-about .ab-seg { margin-top: clamp(26px, 4vw, 40px); }
.page-about .ab-seg .segmented__panel { padding: 26px 0 0; }
.page-about .ab-seg__title {
  margin: 0 0 12px;
  font-size: 20px;
  font-weight: 600;
  color: var(--indigo-900);
}
.page-about .ab-seg .segmented__panel p {
  max-width: 62ch;
  color: var(--ink);
  line-height: 1.9;
}
.page-about .ab-seg .segmented__panel p + p { margin-top: 14px; }

/* ---------- 时间轴 ---------- */
.page-about .ab-sec--timeline { padding-top: clamp(48px, 7vw, 96px); }
.page-about .ab-tl {
  position: relative;
  margin-top: clamp(28px, 4vw, 48px);
}
.page-about .ab-tl__bg {
  width: 100%;
  height: clamp(120px, 22vw, 220px);
  object-fit: cover;
  display: block;
  border-radius: var(--radius);
  opacity: .9;
}
.page-about .ab-tl::before {
  content: "";
  position: absolute;
  left: 12px;
  top: clamp(150px, 26vw, 260px);
  bottom: 40px;
  width: 1px;
  background: linear-gradient(180deg, var(--stone), rgba(203, 195, 180, .15));
}
.page-about .ab-node {
  position: relative;
  padding: 30px 0 30px 40px;
  border-bottom: 1px solid var(--ab-line);
}
.page-about .ab-node:last-child { border-bottom: 0; }
.page-about .ab-node__dot {
  position: absolute;
  left: 6px;
  top: 40px;
  width: 13px;
  height: 13px;
  border-radius: 50%;
  background: var(--paper);
  border: 2px solid var(--gold);
  box-shadow: 0 0 0 4px rgba(224, 169, 78, .16);
}
.page-about .ab-node--now .ab-node__dot {
  background: var(--gold);
  box-shadow: 0 0 0 5px rgba(224, 169, 78, .22);
}
.page-about .ab-node__year {
  display: block;
  font-family: var(--font-num);
  font-size: clamp(26px, 4vw, 38px);
  line-height: 1;
  color: var(--indigo-600);
  letter-spacing: -.01em;
  margin-bottom: 12px;
}
.page-about .ab-node__title {
  margin: 12px 0 0;
  font-size: clamp(19px, 2.4vw, 24px);
  font-weight: 600;
  color: var(--indigo-900);
  line-height: 1.4;
}
.page-about .ab-node__body p {
  margin: 12px 0 0;
  max-width: 64ch;
  color: var(--ink);
  line-height: 1.9;
}
.page-about .ab-node__body .tag { margin: 0; }

/* ---------- 服务版图 ---------- */
.page-about .ab-sec--map { padding-top: clamp(48px, 7vw, 96px); }
.page-about .ab-map__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(26px, 4vw, 44px);
  align-items: start;
}
.page-about .ab-map__text .prose { margin-top: 18px; }
.page-about .ab-map__stats {
  margin-top: 28px;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  background: var(--ab-line);
  border: 1px solid var(--ab-line);
}
.page-about .ab-map__stats .stat {
  background: var(--paper-lift);
  padding: 18px 14px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.page-about .ab-map__stats .stat__num {
  font-family: var(--font-num);
  font-size: clamp(26px, 4vw, 40px);
  color: var(--indigo-800);
  line-height: 1;
}
.page-about .ab-map__stats .stat__label {
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--muted);
  letter-spacing: .04em;
}
.page-about .ab-map__cities {
  margin: 22px 0 0;
  font-size: 13px;
  letter-spacing: .12em;
  color: var(--indigo-600);
}
.page-about .ab-map__figure { margin: 0; }
.page-about .ab-map__figure .figure__frame {
  border: 1px solid var(--ab-line);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--indigo-900);
}
.page-about .ab-map__figure .figure__img {
  width: 100%;
  height: auto;
  display: block;
  object-fit: cover;
}
.page-about .ab-map__figure .figure__cap {
  margin-top: 12px;
  font-size: 12.5px;
  letter-spacing: .04em;
  color: var(--muted);
  line-height: 1.7;
}

/* ---------- 团队 ---------- */
.page-about .ab-team {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(26px, 4vw, 44px);
  margin-top: clamp(26px, 4vw, 40px);
  align-items: start;
}
.page-about .ab-team__figure { margin: 0; }
.page-about .ab-team__figure .figure__frame {
  border: 1px solid var(--ab-line);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--indigo-900);
}
.page-about .ab-team__figure .figure__img {
  width: 100%;
  height: auto;
  display: block;
  object-fit: cover;
}
.page-about .ab-team__figure .figure__cap {
  margin-top: 12px;
  font-size: 12.5px;
  color: var(--muted);
  line-height: 1.7;
}
.page-about .ab-roles {
  margin: clamp(24px, 3vw, 34px) 0 0;
  padding: 0;
  border-top: 1px solid var(--ab-line);
}
.page-about .ab-roles__row {
  display: grid;
  grid-template-columns: 1fr;
  gap: 4px;
  padding: 16px 0;
  border-bottom: 1px solid var(--ab-line);
}
.page-about .ab-roles__row dt {
  font-size: 15px;
  font-weight: 600;
  color: var(--indigo-800);
  letter-spacing: .06em;
}
.page-about .ab-roles__row dd {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--muted);
}
.page-about .ab-team__cta { margin: 26px 0 0; }

/* ---------- 安全与协作 ---------- */
.page-about .ab-sec--trust { padding-top: clamp(48px, 7vw, 96px); }
.page-about .ab-trust__grid {
  margin-top: clamp(26px, 4vw, 40px);
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
  border-top: 1px solid var(--ab-line);
}
.page-about .ab-trust__card {
  padding: 26px 0;
  border-bottom: 1px solid var(--ab-line);
}
.page-about .ab-trust__title {
  margin: 0 0 10px;
  font-size: 18px;
  font-weight: 600;
  color: var(--indigo-900);
}
.page-about .ab-trust__card p {
  margin: 0;
  max-width: 58ch;
  color: var(--ink);
  font-size: 15.5px;
  line-height: 1.9;
}
.page-about .ab-trust__card p + p { margin-top: 12px; }

/* ---------- 结尾 ---------- */
.page-about .ab-sec--end { padding-top: clamp(48px, 7vw, 96px); }
.page-about .ab-end {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(28px, 4vw, 48px);
  background: var(--indigo-800);
  color: var(--on-deep);
  border-radius: var(--radius);
  padding: clamp(28px, 5vw, 52px);
}
.page-about .ab-end .eyebrow { color: var(--sky); }
.page-about .ab-end .section-title { color: #fff; }
.page-about .ab-end .lede { color: var(--on-deep); opacity: .9; margin-top: 18px; }
.page-about .ab-end__actions {
  margin-top: 26px;
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}
.page-about .ab-end__contact-title {
  margin: 0 0 14px;
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--sky);
}
.page-about .ab-end__list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--hair-deep);
}
.page-about .ab-end__list li {
  display: grid;
  grid-template-columns: 76px 1fr;
  gap: 12px;
  padding: 12px 0;
  border-bottom: 1px solid var(--hair-deep);
  font-size: 14.5px;
  line-height: 1.75;
}
.page-about .ab-end__key {
  color: var(--sky);
  letter-spacing: .08em;
  font-size: 12.5px;
  padding-top: 3px;
}
.page-about .ab-end__val {
  color: var(--on-deep);
  word-break: break-word;
}
.page-about .ab-end__legal {
  margin: 18px 0 0;
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--on-deep-dim);
}

/* ---------- 平板 ---------- */
@media (min-width: 760px) {
  .page-about .ab-hero__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .ab-uses {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .page-about .ab-use {
    border-bottom: 0;
    border-right: 1px solid var(--ab-line);
    padding: 28px 22px;
  }
  .page-about .ab-use:first-child { padding-left: 0; }
  .page-about .ab-use:last-child { border-right: 0; padding-right: 0; }
  .page-about .ab-roles__row {
    grid-template-columns: 92px 1fr;
    gap: 18px;
    align-items: baseline;
  }
  .page-about .ab-trust__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 0 40px;
  }
}

/* ---------- 桌面：左侧刻度栏固定 ---------- */
@media (min-width: 1024px) {
  .page-about .ab-body {
    grid-template-columns: 216px minmax(0, 1fr);
    gap: clamp(40px, 5vw, 76px);
    align-items: start;
  }
  .page-about .ab-rail {
    position: sticky;
    top: calc(var(--bar-h) + 28px);
    border-bottom: 0;
    border-right: 1px solid var(--ab-line);
    padding: 46px 26px 20px 0;
  }
  .page-about .ab-rail__list {
    flex-direction: column;
    gap: 0;
    position: relative;
  }
  .page-about .ab-rail__list::before {
    content: "";
    position: absolute;
    left: 3px;
    top: 10px;
    bottom: 10px;
    width: 1px;
    background: linear-gradient(180deg, var(--gold), rgba(203, 195, 180, .2));
  }
  .page-about .ab-rail__item { position: relative; }
  .page-about .ab-rail__link {
    display: flex;
    flex-direction: column;
    gap: 2px;
    padding: 10px 0 10px 20px;
    border-bottom: 0;
  }
  .page-about .ab-rail__link::before {
    content: "";
    position: absolute;
    left: 0;
    top: 16px;
    width: 7px;
    height: 7px;
    border-radius: 50%;
    background: var(--paper);
    border: 1px solid var(--stone);
    transition: background .25s var(--ease), border-color .25s var(--ease);
  }
  .page-about .ab-rail__link:hover::before,
  .page-about .ab-rail__link:focus-visible::before {
    background: var(--gold);
    border-color: var(--gold);
  }
  .page-about .ab-rail__year { font-size: 20px; }
  .page-about .ab-map__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  }
  .page-about .ab-team {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
  }
  .page-about .ab-end {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    padding: clamp(40px, 4vw, 60px);
  }
  .page-about .ab-tl::before { left: 15px; }
  .page-about .ab-node { padding-left: 56px; }
  .page-about .ab-node__dot { left: 9px; }
  .page-about .ab-tl__bg { height: clamp(180px, 18vw, 260px); }
  .page-about .ab-trust__card--wide { max-width: 62ch; }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-rail__link,
  .page-about .ab-rail__link::before,
  .page-about .ab-link {
    transition: none;
  }
}