.page-about {
  --about-node-bg: var(--cream-200);
  --about-rail-a: var(--cyan-400);
  --about-rail-b: var(--coral-500);
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumbs {
  padding: 28px var(--pad-x) 0;
  max-width: var(--shell-max);
  margin: 0 auto;
}

.page-about .breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  list-style: none;
  margin: 0;
  padding: 0;
  font-size: 13px;
  letter-spacing: .06em;
  color: var(--graphite-600);
}

.page-about .breadcrumb-item + .breadcrumb-item::before {
  content: "/";
  margin-right: 10px;
  color: var(--line-soft);
}

.page-about .breadcrumb-link {
  color: var(--ink-700);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 160ms var(--ease), color 160ms var(--ease);
}

.page-about .breadcrumb-link:hover {
  color: var(--cyan-600);
  border-bottom-color: var(--cyan-600);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding-top: clamp(32px, 5vw, 64px);
  padding-bottom: clamp(56px, 8vw, 104px);
}

.page-about .about-hero-grid {
  display: grid;
  gap: 40px;
  align-items: end;
}

.page-about .display-title {
  font-size: clamp(34px, 5.6vw, 74px);
  line-height: 1.08;
  letter-spacing: -0.02em;
  margin: 12px 0 24px;
  color: var(--ink-900);
  max-width: 15em;
}

.page-about .about-hero .lede {
  max-width: 38em;
  margin: 0;
}

.page-about .hero-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 0;
  background: var(--line-soft);
  clip-path: var(--cut-path);
  overflow: hidden;
}

.page-about .hero-facts .fact {
  background: var(--cream-200);
  padding: 20px 22px;
}

.page-about .hero-facts .fact--accent {
  background: var(--ink-900);
}

.page-about .hero-facts .fact--accent dt {
  color: var(--cyan-400);
}

.page-about .hero-facts .fact--accent dd {
  color: var(--cream-100);
  cursor: pointer;
}

.page-about .hero-facts dt {
  margin: 0 0 8px;
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--ink-700);
}

.page-about .hero-facts dd {
  margin: 0;
  font-size: clamp(22px, 2.6vw, 30px);
  font-weight: 700;
  color: var(--ink-900);
  line-height: 1.1;
}

/* ---------- 区块抬头 ---------- */
.page-about .about-head {
  display: grid;
  gap: 20px;
  margin-bottom: clamp(40px, 6vw, 72px);
}

.page-about .about-head-note {
  margin: 0;
  max-width: 40em;
}

.page-about .label--on-ink {
  color: var(--cyan-400);
}

.page-about .about-more {
  margin: clamp(28px, 4vw, 44px) 0 0;
  font-size: 16px;
}

/* ---------- 运营脉络时间轴 ---------- */
.page-about .about-history {
  padding-top: clamp(56px, 8vw, 104px);
  padding-bottom: clamp(56px, 8vw, 104px);
}

.page-about .about-timeline {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  top: 10px;
  bottom: 24px;
  left: 9px;
  width: 2px;
  background: linear-gradient(180deg, var(--about-rail-a) 0%, var(--about-rail-a) 42%, var(--about-rail-b) 100%);
  border-radius: 2px;
}

.page-about .tl-node {
  position: relative;
  padding-left: 42px;
  padding-bottom: 46px;
}

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

.page-about .tl-node::before {
  content: "";
  position: absolute;
  left: 3px;
  top: 9px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--cream-100);
  border: 2px solid var(--cyan-600);
}

.page-about .tl-node--current::before {
  background: var(--coral-500);
  border-color: var(--coral-500);
  box-shadow: 0 0 0 5px rgba(255, 107, 74, .18);
}

.page-about .tl-year {
  display: block;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: .06em;
  color: var(--cyan-600);
  margin-bottom: 8px;
}

.page-about .tl-node--current .tl-year {
  color: var(--coral-700);
}

.page-about .tl-body {
  max-width: 40em;
}

.page-about .tl-body .block-title {
  margin: 0 0 10px;
}

.page-about .tl-body .text-body {
  margin: 0;
}

/* ---------- 团队分工 ---------- */
.page-about .about-team {
  padding-top: clamp(56px, 8vw, 104px);
  padding-bottom: clamp(56px, 8vw, 104px);
}

.page-about .about-team-body {
  display: grid;
  gap: 44px;
}

.page-about .team-media {
  margin: 0;
}

.page-about .team-media img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  aspect-ratio: 3 / 2;
}

.page-about .team-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line-soft);
  clip-path: var(--cut-path);
  overflow: hidden;
}

.page-about .team-card {
  background: var(--cream-100);
  padding: 26px 24px 28px;
  position: relative;
  transition: background 200ms var(--ease);
}

.page-about .team-card:hover {
  background: var(--white);
}

.page-about .team-mark {
  display: block;
  width: 28px;
  height: 4px;
  margin-bottom: 18px;
  background: var(--cyan-400);
  clip-path: polygon(0 0, 100% 0, 78% 100%, 0 100%);
}

.page-about .team-card:nth-child(2) .team-mark { background: var(--azure-500); }
.page-about .team-card:nth-child(3) .team-mark { background: var(--coral-500); }
.page-about .team-card:nth-child(4) .team-mark { background: var(--ink-700); }

.page-about .team-card .block-title {
  margin: 0 0 10px;
}

.page-about .team-card .text-body {
  margin: 0;
  font-size: 15.5px;
}

/* ---------- 更新节奏（深色） ---------- */
.page-about .about-cadence {
  padding-top: clamp(64px, 9vw, 120px);
  padding-bottom: clamp(64px, 9vw, 120px);
}

.page-about .about-cadence .about-head-note {
  color: rgba(246, 241, 230, .78);
}

.page-about .about-cadence .section-title {
  color: var(--cream-100);
}

.page-about .cadence-figure {
  margin: 0 0 clamp(36px, 5vw, 56px);
}

.page-about .cadence-figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  aspect-ratio: 5 / 3;
  clip-path: var(--cut-path);
}

.page-about .about-cadence .media-caption {
  color: rgba(246, 241, 230, .6);
}

.page-about .cadence-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line-ink);
}

.page-about .cadence-item {
  display: grid;
  grid-template-columns: 48px 1fr;
  gap: 18px;
  align-items: start;
  padding: 22px 0;
  border-top: 1px solid var(--line-ink);
}

.page-about .cadence-item:first-child {
  border-top: none;
}

.page-about .cadence-num {
  font-size: 14px;
  color: var(--cyan-400);
  letter-spacing: .05em;
  padding-top: 3px;
}

.page-about .cadence-item p {
  margin: 0;
  color: rgba(246, 241, 230, .88);
  font-size: 16.5px;
  line-height: 1.8;
  max-width: 44em;
}

.page-about .about-cadence .about-more .link-inline {
  color: var(--cyan-400);
  border-bottom-color: rgba(23, 209, 200, .4);
}

.page-about .about-cadence .about-more .link-inline:hover {
  color: var(--cream-100);
  border-bottom-color: var(--cream-100);
}

/* ---------- 内容维护 ---------- */
.page-about .about-docs {
  padding-top: clamp(56px, 8vw, 104px);
  padding-bottom: clamp(56px, 8vw, 104px);
}

.page-about .about-docs-grid {
  display: grid;
  gap: 44px;
}

.page-about .docs-lead .section-title {
  margin: 12px 0 20px;
}

.page-about .docs-lead .text-body {
  margin: 0 0 22px;
}

.page-about .docs-lead .about-more {
  margin-top: 0;
}

.page-about .docs-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 24px;
}

.page-about .docs-item {
  display: grid;
  grid-template-columns: 72px 1fr;
  gap: 20px;
  align-items: start;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .docs-item:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.page-about .docs-num {
  font-size: clamp(28px, 3.4vw, 38px);
  font-weight: 700;
  color: var(--coral-700);
  line-height: 1;
  letter-spacing: -.02em;
}

.page-about .docs-item .block-title {
  margin: 0 0 8px;
  font-size: 18px;
}

.page-about .docs-item .text-body {
  margin: 0;
  font-size: 15.5px;
}

/* ---------- 协作生态 ---------- */
.page-about .about-partners {
  padding-top: clamp(56px, 8vw, 104px);
  padding-bottom: clamp(56px, 8vw, 104px);
}

.page-about .partners-body {
  display: grid;
  gap: 44px;
}

.page-about .partners-media {
  margin: 0;
}

.page-about .partners-media img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  aspect-ratio: 9 / 7;
}

.page-about .partners-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 26px;
}

.page-about .partner-item {
  padding-left: 18px;
  border-left: 2px solid var(--cyan-600);
}

.page-about .partner-item:nth-child(2) { border-left-color: var(--azure-500); }
.page-about .partner-item:nth-child(3) { border-left-color: var(--coral-500); }

.page-about .partner-tag {
  display: block;
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--graphite-600);
  margin-bottom: 8px;
}

.page-about .partner-item .block-title {
  margin: 0 0 8px;
}

.page-about .partner-item .text-body {
  margin: 0;
  font-size: 15.5px;
}

/* ---------- 服务范围 ---------- */
.page-about .about-coverage {
  padding-top: clamp(56px, 8vw, 104px);
  padding-bottom: clamp(56px, 8vw, 104px);
  border-top: 1px solid var(--line-soft);
}

.page-about .about-coverage-grid {
  display: grid;
  gap: 40px;
}

.page-about .about-coverage-grid .section-title {
  margin: 12px 0 20px;
}

.page-about .about-coverage-grid .text-body {
  margin: 0;
}

.page-about .coverage-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line-soft);
  clip-path: var(--cut-path);
  overflow: hidden;
}

.page-about .coverage-item {
  background: var(--cream-200);
  display: grid;
  grid-template-columns: minmax(84px, 110px) 1fr;
  gap: 16px;
  align-items: baseline;
  padding: 18px 20px;
}

.page-about .coverage-k {
  font-size: clamp(18px, 2vw, 22px);
  font-weight: 700;
  color: var(--ink-900);
  letter-spacing: -.01em;
}

.page-about .coverage-v {
  font-size: 15px;
  line-height: 1.7;
  color: var(--ink-700);
}

/* ---------- 下一步 ---------- */
.page-about .about-next {
  padding-top: clamp(56px, 8vw, 104px);
  padding-bottom: clamp(72px, 10vw, 128px);
}

.page-about .next-grid {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 24px;
}

.page-about .next-card {
  position: relative;
  padding: 28px 24px 26px;
  background: var(--cream-200);
  clip-path: var(--cut-path);
  display: flex;
  flex-direction: column;
  gap: 12px;
  transition: transform 220ms var(--ease), background 220ms var(--ease);
}

.page-about .next-card::after {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 4px;
  height: 100%;
  background: var(--cyan-400);
  transform: scaleY(0);
  transform-origin: top;
  transition: transform 240ms var(--ease);
}

.page-about .next-card:hover {
  background: var(--white);
  transform: translateY(-3px);
}

.page-about .next-card:hover::after {
  transform: scaleY(1);
}

.page-about .next-card .block-title {
  margin: 0;
  font-size: 19px;
}

.page-about .next-card .text-body {
  margin: 0;
  font-size: 15px;
  flex: 1;
}

.page-about .next-card .link-inline {
  align-self: flex-start;
  font-size: 15px;
}

/* ---------- 桌面端布局 ---------- */
@media (min-width: 900px) {
  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: clamp(48px, 6vw, 88px);
  }

  .page-about .about-head {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    align-items: end;
    gap: 56px;
  }

  .page-about .about-head-note {
    text-align: right;
    justify-self: end;
  }

  /* 时间轴：左年份右内容 */
  .page-about .about-timeline::before {
    left: 100px;
    top: 14px;
    bottom: 36px;
  }

  .page-about .tl-node {
    display: grid;
    grid-template-columns: 100px minmax(0, 1fr);
    gap: 40px;
    padding-left: 0;
    padding-bottom: clamp(56px, 6vw, 84px);
  }

  .page-about .tl-node::before {
    left: 93px;
    top: 8px;
  }

  .page-about .tl-year {
    text-align: right;
    padding-right: 28px;
    margin-bottom: 0;
    padding-top: 2px;
  }

  .page-about .tl-body {
    max-width: 34em;
  }

  /* 团队分工 */
  .page-about .about-team-body {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: clamp(48px, 5vw, 72px);
    align-items: start;
  }

  .page-about .team-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  /* 内容维护 */
  .page-about .about-docs-grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: clamp(48px, 6vw, 88px);
    align-items: start;
  }

  /* 协作生态 */
  .page-about .partners-body {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: clamp(48px, 5vw, 72px);
    align-items: center;
  }

  .page-about .partners-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 28px;
  }

  .page-about .partner-item {
    padding-left: 20px;
  }

  /* 服务范围 */
  .page-about .about-coverage-grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: clamp(48px, 6vw, 88px);
    align-items: start;
  }

  /* 下一步 */
  .page-about .next-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 28px;
  }
}

@media (min-width: 1180px) {
  .page-about .next-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (max-width: 560px) {
  .page-about .hero-facts {
    grid-template-columns: 1fr;
  }

  .page-about .coverage-item {
    grid-template-columns: 1fr;
    gap: 6px;
  }

  .page-about .docs-item {
    grid-template-columns: 1fr;
    gap: 10px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .team-card,
  .page-about .next-card,
  .page-about .next-card::after,
  .page-about .breadcrumb-link {
    transition: none;
  }

  .page-about .next-card:hover {
    transform: none;
  }
}
</main>