.page-about {
  --about-rail: 88px;
  padding-bottom: clamp(64px, 10vw, 128px);
}

/* ---------- 面包屑位置 ---------- */
.page-about .breadcrumb {
  margin: 24px 0 0;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: clamp(32px, 5vw, 56px) 0 clamp(40px, 6vw, 72px);
  border-bottom: 1px solid var(--line);
}

.page-about .about-hero__ruler {
  height: 6px;
  margin: 20px 0 clamp(20px, 3vw, 32px);
  border-bottom: 1px solid var(--line);
  background-image: repeating-linear-gradient(90deg, var(--line) 0 1px, transparent 1px 24px);
}

.page-about .about-hero__title {
  margin: 0 0 clamp(20px, 3vw, 32px);
  font-family: var(--font-sans);
  font-weight: 200;
  font-size: clamp(36px, 6.4vw, 96px);
  line-height: 1.04;
  letter-spacing: -0.02em;
  color: var(--paper);
  max-width: 15ch;
}

.page-about .about-hero__title strong {
  font-weight: 700;
  color: var(--signal);
}

.page-about .about-hero__lede {
  max-width: 44ch;
  margin: 0;
  font-size: 16px;
  line-height: 1.85;
  color: var(--muted);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.page-about .facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(32px, 5vw, 56px) 0 0;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .facts__cell {
  background: var(--ink-900);
  padding: 18px 16px 16px;
}

.page-about .facts__label {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .facts__num {
  margin: 0;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(24px, 3.4vw, 36px);
  font-weight: 700;
  line-height: 1;
  color: var(--paper);
}

.page-about .facts__unit {
  margin-left: 4px;
  font-size: 12px;
  font-weight: 400;
  color: var(--muted);
}

/* ---------- 通用章节 ---------- */
.page-about .section {
  padding: clamp(48px, 7vw, 112px) 0;
  border-bottom: 1px solid var(--line);
}

.page-about .split {
  display: grid;
  gap: 28px;
}

.page-about .section__title {
  margin: 12px 0 0;
  font-size: clamp(26px, 3.4vw, 44px);
  font-weight: 300;
  line-height: 1.16;
  letter-spacing: -0.01em;
  color: var(--paper);
  max-width: 14ch;
}

.page-about .section__note {
  margin: 16px 0 0;
  font-size: 13px;
  line-height: 1.75;
  color: var(--muted);
  max-width: 26ch;
}

.page-about .prose {
  color: var(--muted);
  font-size: 16px;
  line-height: 1.85;
}

.page-about .prose p {
  margin: 0 0 18px;
  max-width: 40ch;
}

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

/* ---------- 编年史 ---------- */
.page-about .chronicle__figure {
  margin: 0 0 clamp(28px, 4vw, 44px);
}

.page-about .chronicle {
  display: grid;
  gap: 0;
}

.page-about .chronicle__rail {
  position: sticky;
  top: var(--bar);
  z-index: 3;
  display: flex;
  gap: 22px;
  padding: 10px 0;
  margin-bottom: 20px;
  overflow-x: auto;
  background: var(--ink-900);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  scrollbar-width: none;
}

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

.page-about .chronicle__tick {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 2px 0;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--muted);
  text-decoration: none;
  white-space: nowrap;
  transition: color 0.2s var(--ease);
}

.page-about .chronicle__tick::before {
  content: "";
  width: 12px;
  height: 1px;
  background: var(--line);
  transition: width 0.2s var(--ease), background 0.2s var(--ease);
}

.page-about .chronicle__tick:hover,
.page-about .chronicle__tick:focus-visible {
  color: var(--paper);
}

.page-about .chronicle__tick:hover::before,
.page-about .chronicle__tick:focus-visible::before {
  width: 20px;
  background: var(--violet);
}

.page-about .year-card {
  position: relative;
  margin: 0 0 14px;
  padding: 22px 20px;
  border: 1px solid var(--line);
  border-left: 3px solid var(--line);
  border-radius: 2px;
  background: var(--ink-800);
  box-shadow: var(--shadow-hair);
  scroll-margin-top: calc(var(--bar) + 76px);
  transition: border-color 0.2s var(--ease), background 0.2s var(--ease);
}

.page-about .year-card:hover {
  border-left-color: var(--signal);
}

.page-about .year-card:target {
  border-color: var(--violet);
  border-left-color: var(--violet);
  background: var(--ink-700);
}

.page-about .year-card__year {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 13px;
  letter-spacing: 0.16em;
  color: var(--violet);
}

.page-about .year-card__title {
  margin: 0 0 10px;
  font-size: 19px;
  font-weight: 400;
  line-height: 1.35;
  color: var(--paper);
}

.page-about .year-card__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
  max-width: 38ch;
}

/* ---------- 团队 ---------- */
.page-about .crew {
  list-style: none;
  margin: clamp(28px, 4vw, 44px) 0 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.page-about .crew__item {
  padding: 18px 0 20px;
  border-bottom: 1px solid var(--line);
}

.page-about .crew__bar {
  display: block;
  height: 3px;
  margin-bottom: 14px;
  background: var(--ink-700);
}

.page-about .crew__fill {
  display: block;
  height: 100%;
  width: 10%;
  background: var(--signal);
  transition: width 0.4s var(--ease);
}

.page-about .crew__item:nth-child(1) .crew__fill { width: 26%; }
.page-about .crew__item:nth-child(2) .crew__fill { width: 20%; background: var(--cold); }
.page-about .crew__item:nth-child(3) .crew__fill { width: 33%; background: var(--violet); }
.page-about .crew__item:nth-child(4) .crew__fill { width: 22%; background: var(--amber); }

.page-about .crew__head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  margin: 0;
}

.page-about .crew__name {
  font-size: 17px;
  color: var(--paper);
}

.page-about .crew__count {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 13px;
  color: var(--muted);
}

.page-about .crew__detail {
  margin: 8px 0 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
  max-width: 40ch;
}

.page-about .experts {
  margin-top: clamp(28px, 4vw, 44px);
  padding: 24px 20px;
  border: 1px solid var(--line);
  border-left: 3px solid var(--violet);
  border-radius: 2px;
  background: var(--ink-800);
}

.page-about .experts__num {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(40px, 6vw, 64px);
  font-weight: 700;
  line-height: 1;
  color: var(--violet);
}

.page-about .experts__text {
  margin: 0 0 16px;
  font-size: 15px;
  line-height: 1.85;
  color: var(--muted);
  max-width: 42ch;
}

.page-about .experts__link {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--signal);
  text-decoration: none;
  border-bottom: 1px solid currentColor;
  padding-bottom: 2px;
}

.page-about .experts__link:hover {
  color: var(--paper);
}

/* ---------- 校验流程 ---------- */
.page-about .flow {
  display: grid;
  gap: 14px;
}

.page-about .flow__node {
  position: relative;
  padding: 20px 18px;
  border: 1px solid var(--line);
  border-radius: 2px;
  background: var(--ink-800);
  outline-offset: 3px;
  transition: border-color 0.2s var(--ease), background 0.2s var(--ease);
}

.page-about .flow__node:hover,
.page-about .flow__node:focus-visible {
  border-color: var(--cold);
  background: var(--ink-700);
}

.page-about .flow__step {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--cold);
}

.page-about .flow__name {
  margin: 0 0 8px;
  font-size: 18px;
  font-weight: 400;
  color: var(--paper);
}

.page-about .flow__detail {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
  max-width: 34ch;
}

.page-about .flow__hint {
  margin: 12px 0 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--line);
}

.page-about .cards-three {
  display: grid;
  gap: 12px;
  margin: clamp(24px, 4vw, 36px) 0;
}

.page-about .type-card {
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 2px;
  background: var(--ink-800);
}

.page-about .type-card__name {
  margin: 12px 0 8px;
  font-size: 17px;
  font-weight: 400;
  color: var(--paper);
}

.page-about .type-card__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
}

/* ---------- 覆盖与合作 ---------- */
.page-about .coverage {
  display: grid;
  gap: 22px;
  margin: clamp(24px, 4vw, 36px) 0;
}

.page-about .coverage__name {
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 400;
  color: var(--paper);
  padding-left: 12px;
  border-left: 2px solid var(--signal);
}

.page-about .coverage__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.85;
  color: var(--muted);
  max-width: 40ch;
}

.page-about .partners {
  padding-top: 20px;
  border-top: 1px solid var(--line);
}

.page-about .partners__label {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .partners__label:not(:first-child) {
  margin-top: 20px;
}

.page-about .partners__list {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .partner-tile {
  padding: 9px 12px;
  border: 1px solid var(--line);
  border-radius: 2px;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.1em;
  color: var(--muted);
  transition: border-color 0.2s var(--ease), color 0.2s var(--ease);
}

.page-about .partner-tile:hover {
  border-color: var(--signal);
  color: var(--paper);
}

/* ---------- 原则 ---------- */
.page-about .rules {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.page-about .rules__item {
  display: grid;
  grid-template-columns: 40px minmax(0, 1fr);
  gap: 12px;
  padding: 20px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .rules__num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--violet);
  padding-top: 4px;
}

.page-about .rules__name {
  margin: 0 0 6px;
  font-size: 17px;
  font-weight: 400;
  color: var(--paper);
}

.page-about .rules__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
  max-width: 42ch;
}

.page-about .about-cta {
  margin-top: clamp(28px, 4vw, 44px);
  padding: 24px 20px;
  border: 1px solid var(--line);
  border-top: 3px solid var(--signal);
  border-radius: 2px;
  background: var(--ink-800);
}

.page-about .about-cta__text {
  margin: 0 0 18px;
  font-size: 15px;
  line-height: 1.85;
  color: var(--muted);
  max-width: 40ch;
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

/* ---------- 图片容器约束 ---------- */
.page-about .media {
  border: 1px solid var(--line);
  border-radius: 2px;
  overflow: hidden;
  background: var(--ink-800);
}

.page-about .media__img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .media__caption {
  padding: 10px 14px;
  font-size: 12px;
  line-height: 1.7;
  color: var(--muted);
  border-top: 1px solid var(--line);
}

/* ---------- 平板与桌面 ---------- */
@media (min-width: 760px) {
  .page-about .facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

  .page-about .flow__node + .flow__node {
    margin-left: 30px;
  }

  .page-about .flow__node + .flow__node::before {
    content: "";
    position: absolute;
    left: -30px;
    top: 50%;
    width: 30px;
    border-top: 1px dashed var(--line);
  }

  .page-about .cards-three {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .coverage {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 24px;
  }
}

@media (min-width: 900px) {
  .page-about .split {
    grid-template-columns: 5fr 7fr;
    gap: var(--gutter);
    align-items: start;
  }

  .page-about .split__head {
    position: sticky;
    top: calc(var(--bar) + 40px);
  }

  .page-about .section__title {
    font-size: clamp(30px, 3vw, 44px);
  }

  .page-about .chronicle {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: 40px;
  }

  .page-about .chronicle__rail {
    flex-direction: column;
    gap: 0;
    top: calc(var(--bar) + 40px);
    padding: 0;
    margin-bottom: 0;
    overflow: visible;
    background: transparent;
    border-top: 0;
    border-bottom: 0;
    border-left: 1px solid var(--line);
  }

  .page-about .chronicle__tick {
    padding: 16px 0 16px 18px;
  }

  .page-about .chronicle__tick::before {
    position: absolute;
    left: -1px;
    width: 1px;
    height: 12px;
    background: var(--line);
  }

  .page-about .chronicle__tick {
    position: relative;
  }

  .page-about .chronicle__tick:hover::before,
  .page-about .chronicle__tick:focus-visible::before {
    width: 3px;
    background: var(--violet);
  }

  .page-about .year-card {
    padding: 26px 30px;
    margin-bottom: 22px;
    max-width: 92%;
  }

  .page-about .year-card:nth-child(even) {
    margin-left: 6%;
  }

  .page-about .year-card:nth-child(3n) {
    max-width: 84%;
  }

  .page-about .year-card__text {
    max-width: 44ch;
  }

  .page-about .crew__item {
    padding: 20px 0 22px;
  }

  .page-about .experts {
    padding: 30px 32px;
  }

  .page-about .about-cta {
    padding: 30px 32px;
  }
}

@media (min-width: 1100px) {
  .page-about .about-hero__lede {
    font-size: 17px;
  }

  .page-about .flagship-media {
    margin-bottom: 56px;
  }
}

/* ---------- 悬停展开（仅精确指针设备） ---------- */
@media (hover: hover) and (pointer: fine) and (min-width: 900px) {
  .page-about .crew__detail {
    max-height: 0;
    margin-top: 0;
    opacity: 0;
    overflow: hidden;
    transition: max-height 0.25s var(--ease), opacity 0.2s var(--ease), margin-top 0.25s var(--ease);
  }

  .page-about .crew__item:hover .crew__detail,
  .page-about .crew__item:focus-within .crew__detail {
    max-height: 6em;
    margin-top: 8px;
    opacity: 1;
  }

  .page-about .flow__detail {
    max-height: 0;
    opacity: 0;
    overflow: hidden;
    transition: max-height 0.25s var(--ease), opacity 0.2s var(--ease);
  }

  .page-about .flow__node:hover .flow__detail,
  .page-about .flow__node:focus-visible .flow__detail,
  .page-about .flow__node:focus-within .flow__detail {
    max-height: 8em;
    opacity: 1;
  }
}

@media (hover: none) {
  .page-about .flow__hint {
    display: none;
  }
}