.page-about {
  --about-toc-w: 216px;
  --about-gap: clamp(28px, 4.5vw, 64px);
  --about-rule: rgba(20, 224, 192, 0.14);
  display: block;
  overflow-x: clip;
  background: var(--ink);
  color: var(--paper);
  font-family: var(--font-body);
}

/* ============ 首屏 ============ */
.page-about .about-hero {
  position: relative;
  padding: calc(var(--header-h) + 44px) 0 44px;
  background:
    radial-gradient(120% 100% at 88% 0%, rgba(20, 224, 192, 0.18), transparent 62%),
    radial-gradient(90% 80% at -10% 100%, rgba(255, 90, 46, 0.12), transparent 65%),
    linear-gradient(180deg, var(--night) 0%, var(--ink) 100%);
  border-bottom: 1px solid var(--line);
  overflow: hidden;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  right: -90px;
  bottom: -140px;
  width: 320px;
  height: 320px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(20, 224, 192, 0.22), transparent 70%);
  pointer-events: none;
}

.page-about .about-hero .breadcrumb {
  position: relative;
  z-index: 1;
  margin-bottom: 26px;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  color: var(--muted);
}

.page-about .about-hero .breadcrumb a {
  color: var(--muted);
  text-decoration: none;
}

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

.page-about .about-hero-inner {
  position: relative;
  z-index: 1;
  display: grid;
  gap: 32px;
}

.page-about .about-hero h1 {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.85rem, 6vw, 3.4rem);
  line-height: 1.08;
  letter-spacing: -0.02em;
  margin: 12px 0 0;
  max-width: 17ch;
  color: var(--paper);
}

.page-about .about-lede {
  margin: 20px 0 0;
  max-width: 48ch;
  color: rgba(234, 247, 244, 0.78);
  font-size: 1rem;
  line-height: 1.95;
}

.page-about .about-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

.page-about .about-stats {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .about-stat {
  display: flex;
  flex-direction: column;
  gap: 8px;
  min-width: 0;
  padding: 18px 16px 20px;
  background: linear-gradient(180deg, rgba(10, 42, 34, 0.92), rgba(4, 23, 15, 0.94));
}

.page-about .stat-line {
  display: inline-flex;
  align-items: baseline;
  gap: 4px;
}

.page-about .about-stat .stat-value {
  font-family: var(--font-mono);
  font-size: clamp(1.45rem, 4vw, 2rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.03em;
  font-variant-numeric: tabular-nums;
  color: var(--cyan);
}

.page-about .about-stat:nth-child(2) .stat-value {
  color: var(--cyan-soft);
}

.page-about .about-stat:nth-child(3) .stat-value {
  color: var(--pulse);
}

.page-about .about-stat:nth-child(4) .stat-value {
  color: var(--amber);
}

.page-about .stat-unit {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--muted);
}

.page-about .about-stat .stat-label {
  font-size: 0.8rem;
  line-height: 1.5;
  color: var(--muted);
}

/* ============ 主体骨架 ============ */
.page-about .about-body {
  display: grid;
  gap: 28px;
  padding-top: 40px;
  padding-bottom: 56px;
}

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

.page-about .toc-title {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--muted);
  margin: 0 0 10px;
}

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

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

.page-about .toc-list li {
  flex: 0 0 auto;
}

.page-about .toc-list a {
  display: block;
  padding: 7px 14px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: rgba(10, 42, 34, 0.55);
  color: var(--muted);
  font-size: 0.84rem;
  line-height: 1.4;
  text-decoration: none;
  white-space: nowrap;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease), background 0.18s var(--ease);
}

.page-about .toc-list a:hover,
.page-about .toc-list a:focus-visible {
  color: var(--cyan-soft);
  border-color: rgba(20, 224, 192, 0.5);
  background: var(--glass);
}

.page-about .about-section {
  margin: 0;
  padding: 0;
}

.page-about .about-section + .about-section {
  margin-top: 52px;
  padding-top: 44px;
  border-top: 1px solid var(--about-rule);
}

.page-about .section-head {
  margin-bottom: 22px;
}

.page-about .section-title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(1.35rem, 3.4vw, 1.95rem);
  line-height: 1.22;
  letter-spacing: -0.02em;
  color: var(--paper);
  margin: 8px 0 0;
  max-width: 26ch;
}

.page-about .about-copy p {
  color: rgba(234, 247, 244, 0.82);
  font-size: 1rem;
  line-height: 1.95;
  margin: 0 0 18px;
  max-width: 68ch;
}

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

/* ============ 图片容器 ============ */
.page-about .media-frame {
  position: relative;
  margin: 0;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  overflow: hidden;
  background: linear-gradient(140deg, var(--ink-3), var(--ink));
}

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

.page-about .about-timeline-fig {
  margin-top: 24px;
}

/* ============ 时间线 ============ */
.page-about .tl-rail {
  margin-top: 26px;
  padding: 10px 2px 10px;
  overflow-x: auto;
  overflow-y: hidden;
  -webkit-overflow-scrolling: touch;
  scroll-snap-type: x proximity;
  scrollbar-width: thin;
}

.page-about .tl-list {
  position: relative;
  display: flex;
  gap: 14px;
  list-style: none;
  margin: 0;
  padding: 0 40px 0 0;
  min-width: max-content;
}

.page-about .tl-list::before {
  content: "";
  position: absolute;
  top: 8px;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--cyan) 0%, rgba(20, 224, 192, 0.3) 55%, var(--line) 100%);
}

.page-about .tl-item {
  position: relative;
  flex: 0 0 auto;
  width: 78vw;
  max-width: 300px;
  padding-top: 34px;
  scroll-snap-align: start;
}

.page-about .tl-item::before {
  content: "";
  position: absolute;
  top: 2px;
  left: 0;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--ink);
  border: 2px solid var(--cyan);
  box-shadow: 0 0 0 5px rgba(20, 224, 192, 0.12);
}

.page-about .tl-year {
  display: block;
  font-family: var(--font-mono);
  font-size: 1.3rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  font-variant-numeric: tabular-nums;
  color: var(--cyan);
  margin-bottom: 10px;
}

.page-about .tl-card {
  background: rgba(10, 42, 34, 0.72);
  border: 1px solid var(--line);
  border-radius: var(--radius-s);
  overflow: hidden;
  transition: border-color 0.2s var(--ease), box-shadow 0.2s var(--ease);
}

.page-about .tl-card[open] {
  border-color: rgba(20, 224, 192, 0.38);
  box-shadow: 0 18px 36px -28px rgba(20, 224, 192, 0.75);
}

.page-about .tl-summary {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 10px;
  padding: 12px 14px;
  cursor: pointer;
  font-size: 0.92rem;
  font-weight: 600;
  line-height: 1.55;
  color: var(--paper);
  list-style: none;
}

.page-about .tl-summary::-webkit-details-marker {
  display: none;
}

.page-about .tl-summary::after {
  content: "+";
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: 1rem;
  line-height: 1.4;
  color: var(--cyan);
}

.page-about .tl-card[open] .tl-summary::after {
  content: "−";
}

.page-about .tl-body {
  margin: 0;
  padding: 0 14px 14px;
  color: rgba(234, 247, 244, 0.76);
  font-size: 0.88rem;
  line-height: 1.85;
}

/* ============ 图文分栏 ============ */
.page-about .about-split {
  display: grid;
  gap: 24px;
  margin-top: 22px;
}

.page-about .about-split .about-copy p {
  max-width: 58ch;
}

/* ============ 全宽色块 ============ */
.page-about .about-band {
  margin: 12px 0;
  padding: 52px 0;
  background:
    radial-gradient(90% 140% at 92% 0%, rgba(20, 224, 192, 0.2), transparent 62%),
    radial-gradient(70% 120% at 0% 100%, rgba(255, 90, 46, 0.14), transparent 60%),
    linear-gradient(105deg, var(--ink-3) 0%, var(--ink-2) 58%, var(--night) 100%);
  border-top: 1px solid rgba(20, 224, 192, 0.22);
  border-bottom: 1px solid rgba(20, 224, 192, 0.22);
}

.page-about .about-band-inner {
  display: grid;
  gap: 18px;
}

.page-about .band-kicker {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--amber);
  margin: 0 0 10px;
}

.page-about .band-title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(1.5rem, 5vw, 2.25rem);
  line-height: 1.16;
  letter-spacing: -0.02em;
  color: var(--paper);
  margin: 0;
  max-width: 17ch;
}

.page-about .band-text {
  margin: 0;
  color: rgba(234, 247, 244, 0.84);
  font-size: 1rem;
  line-height: 1.95;
}

/* ============ 尾段 ============ */
.page-about .about-body--tail {
  padding-top: 52px;
  padding-bottom: 72px;
}

.page-about .about-article--tail {
  grid-column: 1 / -1;
}

.page-about .about-inline-link {
  margin: 22px 0 0;
}

.page-about .about-next {
  margin-top: 52px;
  padding-top: 38px;
  border-top: 1px solid var(--about-rule);
}

.page-about .next-title {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--muted);
  margin: 0;
  font-weight: 600;
}

.page-about .next-list {
  list-style: none;
  margin: 18px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .next-list a {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 16px 18px;
  border-radius: var(--radius-s);
  border: 1px solid var(--line);
  background: linear-gradient(135deg, rgba(10, 42, 34, 0.85), rgba(4, 23, 15, 0.88));
  color: var(--paper);
  font-size: 0.94rem;
  line-height: 1.55;
  text-decoration: none;
  transition: border-color 0.2s var(--ease), transform 0.2s var(--ease);
}

.page-about .next-list a::after {
  content: "→";
  flex: 0 0 auto;
  font-family: var(--font-mono);
  color: var(--cyan);
}

.page-about .next-list a:hover,
.page-about .next-list a:focus-visible {
  border-color: rgba(20, 224, 192, 0.55);
  transform: translateX(4px);
}

/* ============ 断点 ============ */
@media (min-width: 640px) {
  .page-about .about-hero {
    padding: calc(var(--header-h) + 60px) 0 52px;
  }

  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 860px) {
  .page-about .about-hero-inner {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    align-items: end;
    gap: 48px;
  }

  .page-about .about-band-inner {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.1fr);
    align-items: center;
    gap: 44px;
  }

  .page-about .about-split {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    gap: 34px;
    align-items: start;
  }

  .page-about .next-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 12px;
  }
}

@media (min-width: 1024px) {
  .page-about .about-body {
    grid-template-columns: var(--about-toc-w) minmax(0, 1fr);
    gap: var(--about-gap);
    padding-top: 64px;
    padding-bottom: 0;
  }

  .page-about .about-body--tail {
    grid-template-columns: var(--about-toc-w) minmax(0, 1fr);
    gap: var(--about-gap);
    padding-top: 56px;
    padding-bottom: 96px;
  }

  .page-about .about-article--tail {
    grid-column: 2;
  }

  .page-about .about-toc {
    position: sticky;
    top: calc(var(--header-h) + 24px);
    align-self: start;
  }

  .page-about .toc-list {
    flex-direction: column;
    gap: 2px;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .toc-list a {
    border: 0;
    border-left: 2px solid var(--line);
    border-radius: 0;
    background: transparent;
    padding: 6px 0 6px 14px;
    font-size: 0.85rem;
    line-height: 1.55;
    white-space: normal;
  }

  .page-about .toc-list a:hover,
  .page-about .toc-list a:focus-visible {
    border-left-color: var(--cyan);
    background: linear-gradient(90deg, rgba(20, 224, 192, 0.12), transparent 70%);
    color: var(--cyan-soft);
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about .next-list a,
  .page-about .toc-list a,
  .page-about .tl-card {
    transition: none;
  }

  .page-about .next-list a:hover,
  .page-about .next-list a:focus-visible {
    transform: none;
  }
}