.page-about {
  --about-rail-w: 156px;
}

/* ---------- 面包屑与首屏 ---------- */
.page-about .breadcrumbs {
  padding: 22px 0 0;
  font-size: 13px;
}

.page-about .about-hero {
  position: relative;
  padding: 34px 0 40px;
  border-bottom: 1px solid var(--edge);
}

.page-about .about-hero .eyebrow {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 0;
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--text-3);
}

.page-about .about-hero .eyebrow::before {
  content: "";
  flex: 0 0 auto;
  width: 46px;
  height: 5px;
  background: linear-gradient(90deg, var(--c-red) 0 50%, var(--c-yellow) 50% 100%);
}

.page-about .about-hero h1 {
  margin: 16px 0 0;
  max-width: 20ch;
  font-size: clamp(30px, 6.4vw, 54px);
  line-height: 1.14;
  letter-spacing: -.01em;
  font-weight: 800;
}

.page-about .about-hero-lead {
  margin: 20px 0 0;
  max-width: 46ch;
  font-size: 16px;
  line-height: 1.8;
  color: var(--text-2);
}

.page-about .hero-stat-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 32px 0 0;
  padding: 0;
  list-style: none;
  background: var(--edge);
  border: 1px solid var(--edge);
}

.page-about .hero-stat {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 18px 18px 16px;
  background: var(--surface);
}

.page-about .hero-stat-num {
  font-size: clamp(24px, 5vw, 34px);
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--text);
}

.page-about .hero-stat-unit {
  margin-left: 2px;
  font-size: .5em;
  color: var(--text-2);
}

.page-about .hero-stat-label {
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--text-3);
}

/* ---------- 时间线主骨架 ---------- */
.page-about .about-layout {
  padding-top: 40px;
  padding-bottom: 72px;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--gap-l);
}

.page-about .year-rail {
  border-bottom: 1px solid var(--edge);
  padding-bottom: 14px;
}

.page-about .year-rail-title {
  margin: 0 0 10px;
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--text-3);
}

.page-about .year-list {
  display: flex;
  gap: 6px;
  margin: 0;
  padding: 0;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .year-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px 8px;
  white-space: nowrap;
  text-decoration: none;
  color: var(--text-3);
  border-bottom: 2px solid transparent;
  transition: color .18s var(--ease), border-color .18s var(--ease);
}

.page-about .year-num {
  font-size: 14px;
  letter-spacing: .04em;
}

.page-about .year-tag {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--c-yellow);
}

.page-about .year-link:hover {
  color: var(--text);
  border-bottom-color: var(--c-yellow);
}

.page-about .year-link:focus-visible {
  outline: 2px solid var(--c-yellow);
  outline-offset: 2px;
  color: var(--text);
}

.page-about .about-flow {
  display: grid;
  gap: var(--gap-l);
  min-width: 0;
}

/* ---------- 面板内部 ---------- */
.page-about .about-para {
  margin: 0 0 16px;
  max-width: 44ch;
  line-height: 1.8;
  color: var(--text-2);
}

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

.page-about .about-figure {
  margin: 24px 0 0;
}

.page-about .about-figure .media-caption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--text-3);
}

/* ---------- 团队条 ---------- */
.page-about .team-bars {
  display: grid;
  gap: 14px;
  margin: 0 0 22px;
}

.page-about .team-bar {
  display: grid;
  grid-template-columns: 52px minmax(0, 1fr) 54px;
  align-items: center;
  gap: 12px;
}

.page-about .team-city {
  font-size: 13px;
  letter-spacing: .06em;
  color: var(--text-2);
}

.page-about .team-track {
  display: block;
  height: 14px;
  background: rgba(30, 51, 80, .65);
}

.page-about .team-fill {
  display: block;
  height: 100%;
}

.page-about .team-fill--a { width: 50%; background: var(--c-red); }
.page-about .team-fill--b { width: 30%; background: var(--c-yellow); }
.page-about .team-fill--c { width: 20%; background: var(--c-ok); }

.page-about .team-count {
  font-size: 13px;
  text-align: right;
  color: var(--text);
}

.page-about .team-note {
  margin: 0;
  max-width: 46ch;
  line-height: 1.8;
  color: var(--text-2);
}

/* ---------- 流程 ---------- */
.page-about .flow-nodebar {
  display: block;
  width: 100%;
  height: auto;
  margin: 4px 0 24px;
}

.page-about .fnb-track {
  stroke: var(--edge);
  stroke-width: 2;
}

.page-about .fnb-node--a { fill: var(--c-red); }
.page-about .fnb-node--b { fill: var(--c-yellow); }

.page-about .fnb-text {
  fill: var(--text-3);
  font-family: var(--font-mono);
  font-size: 16px;
  letter-spacing: .04em;
}

.page-about .flow-list {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
  background: var(--edge);
  border: 1px solid var(--edge);
}

.page-about .flow-item {
  position: relative;
  padding: 18px 20px 20px;
  background: var(--surface);
}

.page-about .flow-item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: transparent;
  transition: background .18s var(--ease);
}

.page-about .flow-item:hover::before {
  background: var(--c-red);
}

.page-about .flow-item:focus-within::before {
  background: var(--c-red);
}

.page-about .flow-idx {
  display: block;
  margin-bottom: 8px;
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--c-yellow);
}

.page-about .flow-item h3 {
  margin: 0 0 8px;
  font-size: 17px;
  letter-spacing: -.01em;
}

.page-about .flow-item p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--text-2);
}

/* ---------- 时间线 ---------- */
.page-about .timeline {
  position: relative;
  margin: 4px 0 0;
  padding: 0 0 0 28px;
  list-style: none;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 10px;
  bottom: 12px;
  width: 2px;
  background: linear-gradient(180deg, var(--c-yellow) 0%, var(--c-red) 60%, var(--edge) 100%);
}

.page-about .tl-item {
  position: relative;
  padding-bottom: 26px;
}

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

.page-about .tl-item::before {
  content: "";
  position: absolute;
  left: -25px;
  top: 8px;
  width: 12px;
  height: 12px;
  background: var(--c-panel);
  border: 2px solid var(--c-yellow);
  transform: rotate(45deg);
  transition: border-color .18s var(--ease), background .18s var(--ease);
}

.page-about .tl-item:hover::before {
  border-color: var(--c-red);
  background: var(--c-red);
}

.page-about .tl-item--current::before {
  border-color: var(--c-red);
  background: var(--c-red);
}

.page-about .tl-head {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 10px;
  margin: 0 0 6px;
}

.page-about .tl-year {
  font-size: 14px;
  letter-spacing: .08em;
  color: var(--text-3);
}

.page-about .tl-ver {
  font-size: 22px;
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--text);
}

.page-about .tl-title {
  margin: 0 0 6px;
  font-size: 17px;
  letter-spacing: -.01em;
}

.page-about .tl-desc {
  margin: 0;
  max-width: 46ch;
  font-size: 15px;
  line-height: 1.78;
  color: var(--text-2);
}

/* ---------- 生态四格 ---------- */
.page-about .eco-grid {
  gap: 1px;
}

.page-about .eco-cell {
  padding: 20px 22px;
  background: rgba(18, 35, 61, .72);
  border-left: 3px solid var(--edge);
  transition: border-color .18s var(--ease), transform .18s var(--ease);
}

.page-about .eco-cell:hover {
  border-left-color: var(--c-red);
  transform: translateY(-2px);
}

.page-about .eco-title {
  margin: 0 0 8px;
  font-size: 16px;
  letter-spacing: -.01em;
}

.page-about .eco-cell p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--text-2);
}

/* ---------- 链接行 ---------- */
.page-about .link-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 22px 0 0;
}

/* ---------- 平板及以上 ---------- */
@media (min-width: 680px) {
  .page-about .hero-stat-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

  .page-about .flow-item {
    padding: 22px 24px 24px;
  }
}

/* ---------- 桌面：左年份索引 + 右内容流 ---------- */
@media (min-width: 1000px) {
  .page-about .about-layout {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: 44px;
    padding-top: 48px;
  }

  .page-about .year-rail {
    position: sticky;
    top: calc(var(--head-h) + 28px);
    align-self: start;
    border-bottom: 0;
    border-left: 1px solid var(--edge);
    padding: 0 0 0 16px;
  }

  .page-about .year-list {
    flex-direction: column;
    gap: 2px;
    overflow: visible;
  }

  .page-about .year-link {
    display: flex;
    width: 100%;
    justify-content: space-between;
    padding: 8px 0 8px 10px;
    border-bottom: 0;
    border-left: 2px solid transparent;
    margin-left: -18px;
  }

  .page-about .year-link:hover {
    border-left-color: var(--c-yellow);
  }

  .page-about .timeline {
    padding-left: 34px;
  }

  .page-about .timeline::before {
    left: 9px;
  }

  .page-about .tl-item::before {
    left: -30px;
  }

  .page-about .about-para {
    max-width: 62ch;
  }

  .page-about .team-note,
  .page-about .tl-desc {
    max-width: 62ch;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .year-link,
  .page-about .flow-item::before,
  .page-about .tl-item::before,
  .page-about .eco-cell {
    transition: none;
  }

  .page-about .eco-cell:hover {
    transform: none;
  }
}