.page-about {
  --about-gutter: clamp(20px, 4vw, 56px);
  --about-rail-w: 168px;
  --about-toc-w: 132px;
  --about-gap: 52px;
  --about-num: clamp(40px, 5vw, 62px);
  padding: 0 var(--about-gutter) clamp(72px, 9vw, 120px);
  max-width: 1440px;
  margin: 0 auto;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding: clamp(32px, 5vw, 72px) 0 clamp(28px, 4vw, 52px);
  border-bottom: 1px solid var(--line-soft);
  margin-bottom: clamp(32px, 4.5vw, 64px);
}

.page-about .breadcrumb {
  margin-bottom: clamp(20px, 3vw, 36px);
}

.page-about .hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 28px;
  align-items: end;
}

@media (min-width: 768px) {
  .page-about .hero-grid {
    grid-template-columns: minmax(0, 1fr) minmax(160px, 200px);
    gap: 48px;
  }
}

.page-about .hero-copy h1 {
  font-family: var(--sans);
  font-size: clamp(30px, 4vw, 50px);
  font-weight: 900;
  line-height: 1.16;
  letter-spacing: -0.012em;
  color: var(--bright);
  margin: 10px 0 22px;
  max-width: 24ch;
}

.page-about .hero-copy .lead {
  max-width: 40em;
  font-size: 17px;
  line-height: 1.8;
  color: var(--text);
  margin: 0;
}

.page-about .hero-figure {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 4px;
  padding-left: 20px;
  border-left: 1px solid var(--line);
}

@media (max-width: 767px) {
  .page-about .hero-figure {
    padding-left: 0;
    padding-top: 20px;
    border-left: none;
    border-top: 1px solid var(--line);
    flex-direction: row;
    align-items: baseline;
    flex-wrap: wrap;
    gap: 8px 12px;
  }
}

.page-about .hero-figure-num {
  font-family: var(--mono);
  font-size: var(--about-num);
  font-weight: 900;
  line-height: 0.9;
  letter-spacing: -0.04em;
  color: var(--orange);
}

.page-about .hero-figure-unit {
  font-family: var(--mono);
  font-size: 14px;
  letter-spacing: 0.18em;
  color: var(--index);
}

.page-about .hero-figure-note {
  font-size: 13px;
  line-height: 1.75;
  color: var(--index);
  max-width: 24ch;
  margin-top: 8px;
}

@media (max-width: 767px) {
  .page-about .hero-figure-note {
    flex: 1 1 100%;
    max-width: 34ch;
    margin-top: 0;
  }
}

/* ---------- 画册骨架 ---------- */
.page-about .about-folio {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  grid-template-areas:
    "rail"
    "main"
    "toc";
  gap: clamp(28px, 4vw, 48px);
}

.page-about .about-rail { grid-area: rail; }
.page-about .about-chapters { grid-area: main; }
.page-about .about-toc { grid-area: toc; }

@media (min-width: 1024px) {
  .page-about .about-folio {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    grid-template-areas: "rail main";
    gap: var(--about-gap);
  }
}

@media (min-width: 1280px) {
  .page-about .about-folio {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr) var(--about-toc-w);
    grid-template-areas: "rail main toc";
  }
}

/* ---------- 左侧时间轴 ---------- */
.page-about .about-rail {
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.page-about .rail-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: row;
  gap: 22px;
  padding: 14px 2px;
  border-top: 1px solid var(--line-soft);
  border-bottom: 1px solid var(--line-soft);
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .rail-node {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 2px;
  flex: 0 0 auto;
}

.page-about .rail-dot {
  display: none;
}

.page-about .rail-year {
  font-family: var(--mono);
  font-size: 14px;
  font-weight: 800;
  letter-spacing: 0.06em;
  color: var(--cyan);
}

.page-about .rail-label {
  font-size: 12px;
  line-height: 1.5;
  color: var(--index);
}

@media (min-width: 1024px) {
  .page-about .rail-list {
    flex: 1;
    flex-direction: column;
    justify-content: space-between;
    gap: 18px;
    padding: 6px 0 6px 26px;
    border-top: none;
    border-bottom: none;
    overflow: visible;
  }

  .page-about .rail-list::before {
    content: "";
    position: absolute;
    left: 5px;
    top: 8px;
    bottom: 8px;
    width: 1px;
    background: linear-gradient(
      to bottom,
      transparent 0,
      var(--line) 6%,
      var(--line) 94%,
      transparent 100%
    );
  }

  .page-about .rail-dot {
    display: block;
    position: absolute;
    left: -26px;
    top: 5px;
    width: 11px;
    height: 11px;
    border-radius: 50%;
    background: var(--ink-900);
    border: 1px solid var(--cyan);
    box-shadow: 0 0 0 3px rgba(79, 240, 208, 0.08);
  }

  .page-about .rail-year {
    font-size: 16px;
    color: var(--bright);
  }
}

/* ---------- 右侧目录 ---------- */
.page-about .about-toc {
  display: none;
}

@media (min-width: 1280px) {
  .page-about .about-toc {
    display: block;
    position: sticky;
    top: calc(var(--header-h) + 32px);
    align-self: start;
    padding-left: 18px;
    border-left: 1px solid var(--line-soft);
  }
}

.page-about .toc-title {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--index);
  margin: 0 0 14px;
}

.page-about .toc-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 9px;
}

.page-about .toc-list a {
  display: block;
  font-size: 13px;
  line-height: 1.4;
  color: var(--index);
  text-decoration: none;
  transition: color 160ms var(--ease);
}

.page-about .toc-list a:hover,
.page-about .toc-list a:focus-visible {
  color: var(--cyan);
}

/* ---------- 叙述列 ---------- */
.page-about .about-chapters {
  display: flex;
  flex-direction: column;
  gap: clamp(32px, 4.5vw, 60px);
}

.page-about .ch {
  display: flex;
  flex-direction: column;
  gap: 22px;
}

.page-about .ch--narrow {
  max-width: 660px;
}

.page-about .ch-index {
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: 0.16em;
  color: var(--cyan-dim);
  margin: 0;
}

.page-about .ch h2 {
  font-family: var(--sans);
  font-size: clamp(24px, 2.9vw, 38px);
  font-weight: 800;
  line-height: 1.22;
  letter-spacing: -0.01em;
  color: var(--bright);
  margin: 0;
  max-width: 24ch;
}

.page-about .ch-body {
  display: flex;
  flex-direction: column;
  gap: 1.15em;
  max-width: 38em;
  font-size: 17px;
  line-height: 1.8;
  color: var(--text);
}

.page-about .ch-body p {
  margin: 0;
}

.page-about .ch-body a {
  color: var(--cyan);
  text-decoration: underline;
  text-decoration-color: rgba(79, 240, 208, 0.38);
  text-underline-offset: 3px;
  transition: text-decoration-color 160ms var(--ease);
}

.page-about .ch-body a:hover,
.page-about .ch-body a:focus-visible {
  text-decoration-color: var(--cyan);
}

.page-about .ch-rule {
  border: none;
  border-top: 1px solid rgba(79, 240, 208, 0.32);
  margin: 0;
  flex: 0 0 auto;
  height: 0;
}

/* ---------- 图片 ---------- */
.page-about .ch-figure {
  margin: 0;
  border-radius: 4px;
  overflow: hidden;
  border: 1px solid var(--line-soft);
  background: var(--ink-800);
}

.page-about .ch-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  aspect-ratio: 14 / 9;
  object-fit: cover;
  filter: saturate(0.7) contrast(1.05) brightness(0.94);
}

.page-about .ch-figure--wide img {
  aspect-ratio: 3 / 2;
}

.page-about .ch-figure--square {
  max-width: 520px;
}

.page-about .ch-figure--square img {
  aspect-ratio: 1 / 1;
}

/* ---------- 数据条 ---------- */
.page-about .ch-stats {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
  border-radius: 4px;
  overflow: hidden;
}

.page-about .ch-stats li {
  background: var(--ink-800);
  padding: 18px 16px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.page-about .ch-stat-num {
  font-family: var(--mono);
  font-size: clamp(20px, 2.4vw, 30px);
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--orange);
  line-height: 1.1;
}

.page-about .ch-stat-label {
  font-size: 13px;
  line-height: 1.5;
  color: var(--index);
}

.page-about .ch-next-line {
  font-size: 15px;
  line-height: 1.8;
  color: var(--text);
  margin: 0;
  padding-left: 14px;
  border-left: 2px solid var(--cyan-dim);
  max-width: 38em;
}

.page-about .ch-next-line a {
  color: var(--cyan);
  text-decoration: underline;
  text-decoration-color: rgba(79, 240, 208, 0.38);
  text-underline-offset: 3px;
}

.page-about .ch-next-line a:hover,
.page-about .ch-next-line a:focus-visible {
  text-decoration-color: var(--cyan);
}

/* ---------- 团队构成 ---------- */
.page-about .team-figure {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 26px;
  align-items: center;
  padding: 24px 22px;
  background: var(--ink-800);
  border: 1px solid var(--line-soft);
  border-left: 2px solid var(--orange);
  border-radius: 4px;
}

@media (min-width: 620px) {
  .page-about .team-figure {
    grid-template-columns: 150px minmax(0, 1fr);
    gap: 34px;
    padding: 28px 30px;
  }
}

.page-about .team-ring {
  margin: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
}

.page-about .team-ring svg {
  display: block;
  width: 100%;
  max-width: 132px;
  height: auto;
}

.page-about .team-ring figcaption {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 3px;
  text-align: center;
}

.page-about .team-num {
  font-family: var(--mono);
  font-size: 26px;
  font-weight: 800;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--orange);
}

.page-about .team-label {
  font-size: 12px;
  line-height: 1.5;
  color: var(--index);
}

.page-about .team-legend {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.page-about .team-legend p {
  margin: 0;
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 14px;
  line-height: 1.6;
  color: var(--text);
}

.page-about .team-legend .team-note {
  display: block;
  font-size: 13px;
  line-height: 1.75;
  color: var(--index);
  padding-top: 12px;
  margin-top: 4px;
  border-top: 1px solid var(--line-soft);
}

.page-about .legend-swatch {
  flex: 0 0 auto;
  width: 12px;
  height: 12px;
  border-radius: 2px;
}

.page-about .swatch-warm { background: var(--orange); }
.page-about .swatch-plain { background: var(--ink-700); }

/* ---------- 结尾动作 ---------- */
.page-about .ch-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

@media (max-width: 480px) {
  .page-about .ch-actions .btn {
    flex: 1 1 100%;
    text-align: center;
  }
}

/* ---------- 可访问性 ---------- */
.page-about .rail-list::-webkit-scrollbar {
  height: 4px;
}

.page-about .rail-list::-webkit-scrollbar-thumb {
  background: var(--line);
  border-radius: 2px;
}

.page-about :focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
}

@media (prefers-reduced-motion: reduce) {
  .page-about [data-reveal] {
    opacity: 1;
    transform: none;
  }
  .page-about .toc-list a,
  .page-about .ch-body a {
    transition: none;
  }
}