.page-about {
  padding-block: clamp(16px, 3vw, 40px) clamp(48px, 8vw, 96px);
}

.page-about .about-shell {
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--pad);
}

.page-about .breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 18px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--muted);
}

.page-about .breadcrumb a {
  color: var(--muted);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}

.page-about .breadcrumb a:hover,
.page-about .breadcrumb a:focus-visible {
  color: var(--ink);
  border-bottom-color: var(--gold);
}

.page-about .breadcrumb-sep {
  color: var(--line);
}

/* ---------- 首屏档案头 ---------- */
.page-about .about-masthead {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  padding: clamp(28px, 5.5vw, 64px) clamp(22px, 4.5vw, 56px);
  background: var(--ink);
  color: var(--paper);
  border-radius: 6px;
  border-bottom: 3px solid var(--gold);
}

.page-about .about-masthead::after {
  content: "";
  position: absolute;
  right: -90px;
  bottom: -150px;
  width: 340px;
  height: 340px;
  border-radius: 50%;
  background: radial-gradient(circle at 32% 32%, rgba(217, 164, 65, 0.24), rgba(217, 164, 65, 0) 70%);
  z-index: -1;
}

.page-about .about-masthead .kicker {
  margin: 0;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.12em;
}

.page-about .about-masthead h1 {
  margin: 14px 0 0;
  max-width: 22ch;
  font-family: var(--serif);
  font-weight: 700;
  font-size: clamp(29px, 5vw, 52px);
  line-height: 1.2;
  letter-spacing: -0.01em;
  color: var(--paper);
}

.page-about .about-masthead .lede {
  margin: 20px 0 0;
  max-width: 62ch;
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.85;
  color: rgba(244, 239, 227, 0.84);
}

.page-about .about-facts {
  list-style: none;
  margin: clamp(26px, 4vw, 38px) 0 0;
  padding: clamp(20px, 3vw, 26px) 0 0;
  border-top: 1px solid rgba(127, 168, 147, 0.35);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px 20px;
}

.page-about .about-facts li {
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-width: 0;
}

.page-about .about-fact-num {
  font-family: var(--serif);
  font-weight: 600;
  font-size: clamp(24px, 3vw, 32px);
  line-height: 1.1;
  color: var(--gold-bright);
}

.page-about .about-fact-label {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.04em;
  color: rgba(244, 239, 227, 0.66);
}

/* ---------- 主体栅格 ---------- */
.page-about .about-layout {
  margin-top: clamp(38px, 6vw, 84px);
  display: grid;
  gap: clamp(28px, 4vw, 44px);
}

.page-about .about-body {
  min-width: 0;
}

/* ---------- 侧栏时间轴 ---------- */
.page-about .about-rail-title {
  margin: 0 0 12px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .about-timeline {
  list-style: none;
  margin: 0;
  padding: 0 0 4px;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.page-about .about-tl-link {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 8px 12px;
  white-space: nowrap;
  text-decoration: none;
  color: var(--body-soft);
  font-size: 13px;
  line-height: 1.2;
  border: 1px solid rgba(127, 168, 147, 0.5);
  border-radius: 4px;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease), background 0.18s var(--ease);
}

.page-about .about-tl-dot {
  flex: none;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--gold);
  transition: transform 0.18s var(--ease);
}

.page-about .about-tl-num {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.04em;
  color: var(--amber);
}

.page-about .about-tl-link:hover,
.page-about .about-tl-link:focus-visible {
  color: var(--ink);
  border-color: var(--gold);
  background: var(--paper-2);
}

.page-about .about-tl-link:hover .about-tl-dot,
.page-about .about-tl-link:focus-visible .about-tl-dot {
  transform: scale(1.2);
}

.page-about .about-rail-note {
  margin: 14px 0 0;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.04em;
  color: var(--muted);
}

/* ---------- 章节 ---------- */
.page-about .about-chapter {
  padding-block: clamp(38px, 6vw, 70px);
  border-top: 1px solid rgba(127, 168, 147, 0.45);
  scroll-margin-top: calc(var(--header-h) + 24px);
}

.page-about .about-chapter:first-child {
  padding-top: 0;
  border-top: 0;
}

.page-about .about-chapter-head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 10px 16px;
  align-items: start;
}

.page-about .about-num {
  font-family: var(--serif);
  font-weight: 600;
  font-size: clamp(46px, 9vw, 100px);
  line-height: 0.82;
  letter-spacing: -0.02em;
  color: var(--gold);
  opacity: 0.3;
  transition: opacity 0.22s var(--ease);
}

.page-about .about-chapter.is-visible .about-num {
  opacity: 0.42;
}

.page-about .about-chapter h2 {
  margin: 0;
  padding-top: 4px;
  font-family: var(--serif);
  font-weight: 700;
  font-size: clamp(20px, 2.6vw, 29px);
  line-height: 1.38;
  color: var(--ink);
  letter-spacing: -0.005em;
}

.page-about .about-lead {
  margin: clamp(18px, 2.5vw, 26px) 0 0;
  padding-left: 16px;
  border-left: 3px solid var(--gold);
  font-size: clamp(15px, 1.8vw, 18px);
  line-height: 1.8;
  font-weight: 500;
  color: var(--ink);
}

.page-about .about-cols {
  margin-top: clamp(22px, 3vw, 30px);
  display: grid;
  gap: 24px;
}

.page-about .about-prose p {
  margin: 0 0 16px;
  font-size: 16px;
  line-height: 1.85;
  color: var(--body-soft);
}

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

.page-about .about-prose--after {
  margin-top: clamp(22px, 3vw, 30px);
}

.page-about .num {
  font-family: var(--serif);
  font-weight: 700;
  font-size: 1.12em;
  color: var(--amber);
  letter-spacing: 0;
}

/* 图片 */
.page-about .about-figure,
.page-about .about-wide-figure {
  margin: 0;
}

.page-about .about-wide-figure {
  margin-top: clamp(26px, 4vw, 40px);
}

.page-about .about-figure img,
.page-about .about-wide-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  border-radius: 6px;
  object-fit: cover;
}

.page-about .figure-caption {
  margin: 10px 0 0;
  font-family: var(--mono);
  font-size: 12px;
  line-height: 1.7;
  letter-spacing: 0.02em;
  color: var(--muted);
}

/* 翻页入口 */
.page-about .about-turn {
  margin: clamp(24px, 3.5vw, 34px) 0 0;
}

.page-about .about-turn a {
  display: inline-flex;
  align-items: baseline;
  gap: 10px;
  padding-bottom: 4px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--ink);
  text-decoration: none;
  border-bottom: 1px solid var(--gold);
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}

.page-about .about-turn-hint {
  font-family: var(--sans);
  font-size: 12px;
  color: var(--muted);
  opacity: 0.75;
  transform: translateX(-2px);
  transition: opacity 0.18s var(--ease), transform 0.18s var(--ease), color 0.18s var(--ease);
}

.page-about .about-turn a:hover .about-turn-hint,
.page-about .about-turn a:focus-visible .about-turn-hint {
  opacity: 1;
  color: var(--amber);
  transform: translateX(2px);
}

/* 演进节点 */
.page-about .about-milestones {
  list-style: none;
  margin: clamp(22px, 3vw, 30px) 0 0;
  padding: 0;
}

.page-about .about-milestone {
  display: grid;
  grid-template-columns: 76px minmax(0, 1fr);
  gap: 14px;
  padding: 15px 0;
  border-top: 1px dashed rgba(127, 168, 147, 0.55);
}

.page-about .about-milestone:last-child {
  border-bottom: 1px dashed rgba(127, 168, 147, 0.55);
}

.page-about .about-ms-label {
  padding-top: 3px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--amber);
}

.page-about .about-ms-title {
  margin: 0 0 6px;
  font-size: 16px;
  font-weight: 600;
  color: var(--ink);
}

.page-about .about-ms-desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--body-soft);
}

/* 三个小组 */
.page-about .about-teams {
  list-style: none;
  margin: clamp(22px, 3vw, 30px) 0 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .about-team {
  padding: 20px 18px;
  background: var(--paper-2);
  border-left: 3px solid var(--gold);
  border-radius: 4px;
}

.page-about .about-team h3 {
  margin: 0 0 8px;
  font-family: var(--serif);
  font-weight: 600;
  font-size: 17px;
  color: var(--ink);
}

.page-about .about-team p {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--body-soft);
}

/* 使用数据 */
.page-about .about-metrics {
  list-style: none;
  margin: clamp(22px, 3vw, 30px) 0 0;
  padding: 0;
  display: grid;
  gap: 18px;
}

.page-about .about-metric {
  padding-top: 12px;
  border-top: 2px solid var(--gold);
}

.page-about .about-metric-num {
  display: block;
  margin-bottom: 6px;
  font-family: var(--serif);
  font-weight: 700;
  font-size: clamp(22px, 3vw, 30px);
  line-height: 1.2;
  color: var(--amber);
}

.page-about .about-metric-label {
  display: block;
  font-size: 14px;
  line-height: 1.7;
  color: var(--muted);
}

/* ---------- 结尾入口 ---------- */
.page-about .about-next {
  margin-top: clamp(44px, 7vw, 92px);
  padding: clamp(26px, 4vw, 46px) clamp(22px, 4vw, 44px);
  background: var(--ink-2);
  color: var(--paper);
  border-radius: 6px;
  border-top: 3px solid var(--gold);
}

.page-about .about-next-title {
  margin: 0;
  font-family: var(--serif);
  font-weight: 700;
  font-size: clamp(21px, 2.8vw, 30px);
  line-height: 1.35;
  color: var(--paper);
}

.page-about .about-next-desc {
  margin: 12px 0 0;
  max-width: 58ch;
  font-size: 15px;
  line-height: 1.8;
  color: rgba(244, 239, 227, 0.78);
}

.page-about .about-links {
  list-style: none;
  margin: clamp(22px, 3vw, 30px) 0 0;
  padding: 0;
  display: grid;
  gap: 2px;
  border-radius: 4px;
  overflow: hidden;
}

.page-about .about-links a {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 16px 18px;
  text-decoration: none;
  background: var(--ink);
  color: var(--paper);
  transition: background 0.18s var(--ease), box-shadow 0.18s var(--ease);
}

.page-about .about-links a:hover,
.page-about .about-links a:focus-visible {
  background: var(--moss);
  box-shadow: inset 3px 0 0 var(--gold);
}

.page-about .about-link-title {
  font-family: var(--serif);
  font-weight: 600;
  font-size: 17px;
  color: var(--gold-bright);
}

.page-about .about-link-desc {
  font-size: 13px;
  line-height: 1.7;
  color: rgba(244, 239, 227, 0.76);
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .about-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

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

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

  .page-about .about-milestone {
    grid-template-columns: 96px minmax(0, 1fr);
    gap: 20px;
  }
}

@media (min-width: 860px) {
  .page-about .about-cols {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    gap: 34px;
    align-items: start;
  }

  .page-about .about-figure {
    margin-top: 4px;
  }
}

@media (min-width: 960px) {
  .page-about .about-layout {
    grid-template-columns: 196px minmax(0, 1fr);
    gap: clamp(40px, 5vw, 72px);
    align-items: start;
  }

  .page-about .about-rail {
    position: sticky;
    top: calc(var(--header-h) + 32px);
  }

  .page-about .about-timeline {
    flex-direction: column;
    gap: 0;
    overflow: visible;
    padding: 0;
  }

  .page-about .about-tl-link {
    display: flex;
    padding: 9px 0 9px 14px;
    border: 0;
    border-left: 1px solid rgba(127, 168, 147, 0.5);
    border-radius: 0;
    white-space: normal;
  }

  .page-about .about-tl-link:hover,
  .page-about .about-tl-link:focus-visible {
    background: transparent;
    border-left-color: var(--gold);
    color: var(--ink);
  }

  .page-about .about-rail-note {
    margin-top: 18px;
    padding-left: 14px;
  }

  .page-about .about-next {
    margin-left: calc(196px + clamp(40px, 5vw, 72px));
  }
}

@media (min-width: 1180px) {
  .page-about .about-chapter-head {
    gap: 8px 22px;
  }

  .page-about .about-cols {
    grid-template-columns: minmax(0, 1.25fr) minmax(0, 0.75fr);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-tl-link,
  .page-about .about-tl-dot,
  .page-about .about-turn a,
  .page-about .about-turn-hint,
  .page-about .about-links a,
  .page-about .about-num,
  .page-about .breadcrumb a {
    transition: none;
  }

  .page-about .about-tl-link:hover .about-tl-dot,
  .page-about .about-tl-link:focus-visible .about-tl-dot {
    transform: none;
  }

  .page-about .about-turn a:hover .about-turn-hint,
  .page-about .about-turn a:focus-visible .about-turn-hint {
    transform: none;
  }
}