.page-about {
  --ab-gap: 32px;
  --ab-fade: rgba(244, 241, 234, 0.78);
  --ab-fade-2: rgba(244, 241, 234, 0.6);
  background: var(--ink);
  color: var(--snow);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: 24px 0 44px;
  border-bottom: 1px solid var(--line-cyan);
  background:
    radial-gradient(120% 90% at 88% 0%, rgba(41, 224, 214, 0.1), transparent 58%),
    radial-gradient(90% 80% at 0% 100%, rgba(217, 164, 65, 0.08), transparent 62%),
    var(--ink);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(41, 224, 214, 0.055) 1px, transparent 1px),
    linear-gradient(90deg, rgba(41, 224, 214, 0.055) 1px, transparent 1px);
  background-size: 72px 72px;
  pointer-events: none;
}

.page-about .about-hero > .shell {
  position: relative;
  z-index: 1;
}

.page-about .breadcrumb {
  margin-bottom: 26px;
}

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

.page-about .hero-kicker {
  display: inline-block;
  margin: 0 0 18px;
  padding: 6px 10px;
  border: 1px solid var(--line-cyan-strong);
  border-radius: var(--r);
  font-family: var(--ff-num);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--cyan);
}

.page-about .hero-grid h1 {
  margin: 0 0 18px;
  font-family: var(--ff-head);
  font-weight: 900;
  font-size: clamp(30px, 6.4vw, 56px);
  line-height: 1.14;
  letter-spacing: -0.02em;
  color: var(--snow);
}

.page-about .hero-lead {
  margin: 0 0 26px;
  max-width: 60ch;
  font-size: 16px;
  line-height: 1.78;
  color: var(--ab-fade);
}

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

.page-about .hero-panel {
  padding: 20px 18px 22px;
  border: 1px solid var(--line-cyan);
  border-left: 2px solid var(--signal);
  border-radius: var(--r);
  background: linear-gradient(180deg, rgba(15, 39, 64, 0.92), rgba(10, 27, 46, 0.92));
  box-shadow: 0 18px 40px -30px rgba(0, 0, 0, 0.9);
}

.page-about .hero-panel-title {
  margin: 0 0 16px;
  font-family: var(--ff-num);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--ab-fade-2);
}

.page-about .hero-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
  margin: 0;
}

.page-about .hero-stat {
  margin: 0;
  min-width: 0;
}

.page-about .hero-stat dt {
  margin-bottom: 5px;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--ab-fade-2);
}

.page-about .hero-stat dd {
  margin: 0;
  font-family: var(--ff-num);
  font-weight: 700;
  font-size: 25px;
  line-height: 1.1;
  letter-spacing: 0.04em;
  color: var(--cyan);
}

.page-about .hero-stat .unit {
  margin-left: 3px;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--ab-fade-2);
}

.page-about .hero-annot {
  display: none;
}

/* ---------- 章节目录 ---------- */
.page-about .about-toc-wrap {
  border-bottom: 1px solid var(--line-cyan);
  background: var(--ink-2);
}

.page-about .about-toc {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding: 12px 0;
  scrollbar-width: none;
}

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

.page-about .about-toc .toc-link {
  flex: 0 0 auto;
  padding: 7px 12px;
  border: 1px solid transparent;
  border-radius: var(--r);
  font-family: var(--ff-num);
  font-size: 12px;
  letter-spacing: 0.1em;
  white-space: nowrap;
  text-decoration: none;
  color: var(--ab-fade-2);
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease), background-color 0.18s var(--ease);
}

.page-about .about-toc .toc-link:hover,
.page-about .about-toc .toc-link:focus-visible {
  color: var(--cyan);
  border-color: var(--line-cyan-strong);
}

.page-about .about-toc .toc-link[aria-current="true"] {
  color: var(--ink);
  background: var(--cyan);
  border-color: var(--cyan);
}

/* ---------- 章节通用 ---------- */
.page-about .about-body {
  display: grid;
}

.page-about .chapter {
  padding: 48px 0 44px;
  border-bottom: 1px solid var(--line-cyan);
}

.page-about .chapter:last-child {
  border-bottom: 0;
}

.page-about .chapter-head {
  max-width: 72ch;
}

.page-about .chapter-index {
  display: flex;
  align-items: baseline;
  gap: 10px;
  margin: 0 0 14px;
  font-family: var(--ff-num);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--cyan);
}

.page-about .chapter-index .num {
  font-size: 20px;
  color: var(--cyan);
}

.page-about .chapter-title {
  margin: 0 0 14px;
  font-family: var(--ff-head);
  font-weight: 800;
  font-size: clamp(23px, 4.4vw, 36px);
  line-height: 1.24;
  letter-spacing: -0.015em;
  color: var(--snow);
}

.page-about .chapter-summary {
  margin: 0 0 26px;
  padding-left: 14px;
  border-left: 2px solid var(--amber);
  font-size: 15px;
  line-height: 1.76;
  color: var(--ab-fade);
}

.page-about .chapter-body > p {
  margin: 0 0 18px;
  max-width: 70ch;
  font-size: 16px;
  line-height: 1.78;
  color: rgba(244, 241, 234, 0.86);
}

.page-about .chapter-body > p:last-child {
  margin-bottom: 0;
}

/* ---------- 图片 ---------- */
.page-about .ab-figure {
  margin: 26px 0;
}

.page-about .ab-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border: 1px solid var(--line-cyan);
  border-radius: var(--r);
  background: var(--ink-2);
}

/* ---------- 时间轴区（浅色分区） ---------- */
.page-about .about-timeline {
  padding: 48px 0 52px;
  background: var(--paper);
  border-top: 1px solid var(--line-dark);
  border-bottom: 1px solid var(--line-dark);
  color: var(--ink);
}

.page-about .about-timeline .chapter-index {
  color: var(--clay);
}

.page-about .about-timeline .chapter-index .num {
  color: var(--clay);
}

.page-about .about-timeline .chapter-title {
  color: var(--ink);
}

.page-about .about-timeline .chapter-summary {
  border-left-color: var(--clay);
  color: var(--stone);
}

.page-about .about-timeline .ab-figure img {
  border-color: var(--line-dark);
  background: var(--snow);
}

.page-about .timeline {
  display: grid;
  grid-auto-flow: column;
  grid-auto-columns: minmax(228px, 82vw);
  gap: 14px;
  margin: 30px 0 0;
  padding: 0 0 10px;
  list-style: none;
  overflow-x: auto;
  scroll-snap-type: x proximity;
  scrollbar-width: thin;
}

.page-about .tl-node {
  scroll-snap-align: start;
  padding: 16px 15px 18px;
  border: 1px solid var(--line-dark);
  border-top: 3px solid var(--moss);
  border-radius: var(--r);
  background: var(--snow);
  transition: transform 0.22s var(--ease), box-shadow 0.22s var(--ease), border-top-color 0.22s var(--ease);
}

.page-about .tl-node:hover,
.page-about .tl-node:focus-within {
  transform: translateY(-4px);
  border-top-color: var(--amber);
  box-shadow: 0 16px 32px -24px rgba(10, 27, 46, 0.6);
}

.page-about .tl-year {
  display: block;
  font-family: var(--ff-num);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--stone);
}

.page-about .tl-tag {
  display: inline-block;
  margin-top: 8px;
  padding: 2px 7px;
  border: 1px solid rgba(217, 164, 65, 0.5);
  border-radius: var(--r);
  font-family: var(--ff-num);
  font-weight: 700;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--clay);
}

.page-about .tl-title {
  margin: 10px 0 8px;
  font-size: 16.5px;
  font-weight: 800;
  line-height: 1.4;
  color: var(--ink);
}

.page-about .tl-node p {
  margin: 0;
  font-size: 14px;
  line-height: 1.72;
  color: var(--stone);
}

/* ---------- 内容链路 ---------- */
.page-about .flow-list {
  display: grid;
  gap: 12px;
  margin: 0 0 8px;
  padding: 0;
  list-style: none;
}

.page-about .flow-step {
  display: grid;
  grid-template-columns: 36px minmax(0, 1fr);
  gap: 12px;
  align-items: start;
  padding: 15px 15px 17px;
  border: 1px solid var(--line-cyan);
  border-radius: var(--r);
  background: rgba(15, 39, 64, 0.5);
}

.page-about .flow-num {
  font-size: 15px;
  line-height: 1.55;
  color: var(--cyan);
}

.page-about .flow-step h3 {
  margin: 0 0 6px;
  font-size: 16px;
  font-weight: 800;
  color: var(--snow);
}

.page-about .flow-step p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.74;
  color: rgba(244, 241, 234, 0.76);
}

/* ---------- 团队 ---------- */
.page-about .team-grid {
  display: grid;
  gap: 12px;
  margin-bottom: 22px;
}

.page-about .team-card {
  padding: 17px 15px 19px;
  border: 1px solid var(--line-cyan);
  border-top: 2px solid var(--moss);
  border-radius: var(--r);
  background: linear-gradient(180deg, rgba(22, 50, 79, 0.72), rgba(10, 27, 46, 0.72));
}

.page-about .team-card:nth-child(2) {
  border-top-color: var(--clay);
}

.page-about .team-card:nth-child(3) {
  border-top-color: var(--amber);
}

.page-about .team-card:nth-child(4) {
  border-top-color: var(--cyan);
}

.page-about .team-title {
  margin: 0 0 8px;
  font-size: 16px;
  font-weight: 800;
  letter-spacing: 0.01em;
  color: var(--snow);
}

.page-about .team-card p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.74;
  color: rgba(244, 241, 234, 0.76);
}

.page-about .team-note {
  max-width: 70ch;
  margin: 0;
  padding-left: 14px;
  border-left: 1px solid var(--line-cyan-strong);
  font-size: 15px;
  line-height: 1.78;
  color: var(--ab-fade);
}

/* ---------- 长期维护 ---------- */
.page-about .maintain-grid {
  display: grid;
  gap: 26px;
}

.page-about .maintain-list {
  display: grid;
  gap: 22px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .maintain-list li {
  position: relative;
  padding-left: 18px;
}

.page-about .maintain-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 9px;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--moss);
}

.page-about .maintain-list h3 {
  margin: 0 0 6px;
  font-size: 16px;
  font-weight: 800;
  color: var(--snow);
}

.page-about .maintain-list p {
  margin: 0;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.76;
  color: rgba(244, 241, 234, 0.8);
}

/* ---------- 收尾 ---------- */
.page-about .about-next {
  border-top: 1px solid var(--line-cyan);
  background:
    linear-gradient(180deg, rgba(41, 224, 214, 0.06), transparent 70%),
    var(--ink-2);
}

.page-about .about-next-inner {
  display: grid;
  gap: 24px;
  padding: 44px 0 52px;
}

.page-about .about-next-k {
  margin: 0 0 12px;
  font-family: var(--ff-num);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--amber);
}

.page-about .about-next h2 {
  margin: 0 0 12px;
  font-family: var(--ff-head);
  font-weight: 800;
  font-size: clamp(22px, 4vw, 32px);
  line-height: 1.26;
  letter-spacing: -0.015em;
  color: var(--snow);
}

.page-about .about-next-lead p {
  margin: 0;
  max-width: 62ch;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--ab-fade);
}

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

/* ---------- 平板 ---------- */
@media (min-width: 640px) {
  .page-about .team-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .timeline {
    grid-auto-columns: minmax(240px, 260px);
  }
}

/* ---------- 桌面 ---------- */
@media (min-width: 900px) {
  .page-about .about-hero {
    padding: 30px 0 60px;
  }

  .page-about .hero-grid {
    grid-template-columns: minmax(0, 1fr) minmax(250px, 300px);
    gap: 48px;
    align-items: start;
  }

  .page-about .chapter {
    padding: 72px 0 64px;
  }

  .page-about .about-timeline {
    padding: 72px 0 76px;
  }

  .page-about .flow-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 14px;
  }

  .page-about .timeline {
    grid-auto-flow: row;
    grid-template-columns: repeat(6, minmax(0, 1fr));
    grid-auto-columns: auto;
    gap: 12px;
    overflow-x: visible;
    padding-bottom: 0;
  }

  .page-about .maintain-grid {
    grid-template-columns: minmax(0, 1fr) 280px;
    gap: 44px;
    align-items: start;
  }

  .page-about .about-next-inner {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    gap: 40px;
    padding: 56px 0 64px;
  }
}

@media (min-width: 1100px) {
  .page-about .team-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-body .chapter-body > p,
  .page-about .chapter-head {
    margin-left: 0;
  }
}

@media (min-width: 1280px) {
  .page-about .hero-annot {
    display: block;
    position: absolute;
    top: 50%;
    right: 10px;
    transform: translateY(-50%) rotate(90deg);
    transform-origin: center;
    font-size: 12px;
    letter-spacing: 0.2em;
    color: rgba(41, 224, 214, 0.42);
    pointer-events: none;
  }
}

/* ---------- 降低动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .tl-node,
  .page-about .about-toc .toc-link {
    transition: none;
  }

  .page-about .tl-node:hover,
  .page-about .tl-node:focus-within {
    transform: none;
  }
}