.page-about {
  --about-grid: rgba(27, 64, 92, 0.45);
  position: relative;
  padding-bottom: 80px;
  color: var(--text);
  background-color: var(--ink-800);
  background-image:
    linear-gradient(to right, var(--about-grid) 1px, transparent 1px),
    linear-gradient(to bottom, var(--about-grid) 1px, transparent 1px);
  background-size: 120px 120px;
  background-position: -1px -1px;
}

.page-about .breadcrumb {
  padding-top: 24px;
  font-family: var(--font-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 160ms var(--ease), border-color 160ms var(--ease);
}

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

.page-about .breadcrumb-sep {
  margin: 0 8px;
  color: var(--line);
}

.page-about .breadcrumb [aria-current="page"] {
  color: var(--cyan);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  display: grid;
  gap: 28px;
  padding: 24px 0 56px;
}

.page-about .about-hero-visual {
  position: relative;
  margin: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--ink-900);
}

.page-about .about-hero-visual img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 9 / 7;
  object-fit: cover;
  opacity: 0.92;
}

.page-about .about-hero-stamp {
  position: absolute;
  left: 16px;
  bottom: 16px;
  display: inline-block;
  padding: 7px 14px;
  border-radius: var(--pill);
  background: var(--amber-soft);
  color: #3a2200;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.04em;
}

.page-about .about-hero-copy .eyebrow {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--amber);
}

.page-about .about-hero h1 {
  margin: 0 0 18px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(34px, 8vw, 72px);
  line-height: 1.08;
  letter-spacing: -0.02em;
  color: var(--text);
}

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

.page-about .about-facts {
  display: grid;
  gap: 12px;
  margin: 28px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-facts li {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 12px 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: rgba(18, 48, 71, 0.6);
}

.page-about .fact-num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 20px;
  color: var(--cyan);
}

.page-about .fact-label {
  font-size: 13px;
  color: var(--muted);
}

/* ---------- 通用章节头 ---------- */
.page-about .section-head {
  padding-bottom: 18px;
  margin-bottom: 28px;
  border-bottom: 1px solid var(--line);
}

.page-about .section-head .eyebrow {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--amber);
}

.page-about .section-title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(24px, 5vw, 42px);
  line-height: 1.2;
  letter-spacing: -0.01em;
  color: var(--text);
}

.page-about .section-lede {
  margin: 14px 0 0;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--muted);
}

/* ---------- 由来 ---------- */
.page-about .about-story {
  padding: 48px 0;
  border-top: 1px solid var(--line);
}

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

.page-about .story-copy h2 {
  margin: 0 0 18px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(24px, 5vw, 40px);
  line-height: 1.22;
  color: var(--text);
}

.page-about .story-copy p {
  margin: 0 0 16px;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--text);
}

.page-about .story-note {
  align-self: start;
  padding: 20px 22px;
  border-left: 3px solid var(--amber);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  background: rgba(18, 48, 71, 0.72);
}

.page-about .story-note .anno {
  margin: 0 0 12px;
  font-family: var(--font-note);
  font-size: 17px;
  line-height: 1.7;
  color: var(--amber-soft);
  text-decoration: underline;
  text-decoration-color: rgba(255, 184, 77, 0.5);
  text-underline-offset: 6px;
  text-decoration-thickness: 1px;
}

.page-about .story-note-body {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--muted);
}

/* ---------- 编号图例 ---------- */
.page-about .about-entries {
  padding: 48px 0;
  border-top: 1px solid var(--line);
}

.page-about .entry-map {
  display: grid;
  gap: 14px;
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: entry;
}

.page-about .entry-map-item {
  position: relative;
  padding: 20px 20px 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: rgba(18, 48, 71, 0.55);
  transition: border-color 180ms var(--ease), background-color 180ms var(--ease), transform 180ms var(--ease);
}

.page-about .entry-map-item::before {
  content: "";
  position: absolute;
  left: 20px;
  top: 0;
  width: 36px;
  height: 3px;
  border-radius: 0 0 3px 3px;
  background: var(--cyan);
}

.page-about .entry-map-item--amber::before {
  background: var(--amber);
}

.page-about .entry-map-item:hover,
.page-about .entry-map-item:focus-within {
  border-color: var(--cyan);
  background: rgba(18, 48, 71, 0.9);
  transform: translateY(-2px);
}

.page-about .entry-map-item--amber:hover,
.page-about .entry-map-item--amber:focus-within {
  border-color: var(--amber);
}

.page-about .entry-map-item .entry-num {
  display: block;
  margin: 8px 0 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--cyan);
}

.page-about .entry-map-item--amber .entry-num {
  color: var(--amber);
}

.page-about .entry-map-item h3 {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 18px;
  line-height: 1.4;
  color: var(--text);
}

.page-about .entry-map-item p {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
}

/* ---------- 团队 ---------- */
.page-about .about-team {
  padding: 48px 0;
  border-top: 1px solid var(--line);
}

.page-about .team-grid {
  display: grid;
  gap: 24px;
}

.page-about .team-panels {
  display: grid;
  gap: 12px;
  align-content: start;
}

.page-about .team-panel {
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: rgba(18, 48, 71, 0.6);
  overflow: hidden;
  transition: border-color 180ms var(--ease);
}

.page-about .team-panel[open] {
  border-color: var(--cyan);
}

.page-about .team-panel summary {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 15px 18px;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 16px;
  color: var(--text);
}

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

.page-about .team-panel summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 16px;
  color: var(--cyan);
  transition: transform 160ms var(--ease);
}

.page-about .team-panel[open] summary::after {
  transform: rotate(45deg);
}

.page-about .team-panel summary:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: -3px;
}

.page-about .team-idx {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--cyan);
  padding: 3px 8px;
  border: 1px solid var(--line);
  border-radius: var(--pill);
}

.page-about .team-panel p {
  margin: 0;
  padding: 0 18px 18px;
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .team-cadence {
  display: grid;
  gap: 8px;
  margin: 8px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .team-cadence li {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 11px 16px;
  border: 1px dashed var(--line);
  border-radius: var(--radius-sm);
  font-size: 13.5px;
  color: var(--muted);
}

.page-about .cadence-key {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--amber);
  padding: 2px 9px;
  border-radius: var(--pill);
  background: rgba(255, 184, 77, 0.12);
}

.page-about .team-visual {
  margin: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--ink-900);
}

.page-about .team-visual img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 4 / 3;
  object-fit: cover;
}

.page-about .team-visual figcaption {
  padding: 12px 16px;
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--muted);
  border-top: 1px solid var(--line);
}

/* ---------- 版本 ---------- */
.page-about .about-versions {
  padding: 48px 0;
  border-top: 1px solid var(--line);
}

.page-about .versions-visual {
  margin: 0 0 32px;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--ink-900);
}

.page-about .versions-visual img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 12 / 5;
  object-fit: cover;
}

.page-about .timeline {
  position: relative;
  margin: 0;
  padding: 0 0 0 18px;
  list-style: none;
  border-left: 1px solid var(--line);
}

.page-about .tl-item {
  position: relative;
  display: grid;
  grid-template-columns: 52px 1fr;
  gap: 14px;
  padding: 0 0 30px;
}

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

.page-about .tl-item::before {
  content: "";
  position: absolute;
  left: -25px;
  top: 6px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--ink-800);
  border: 2px solid var(--cyan);
  transition: background-color 180ms var(--ease), box-shadow 180ms var(--ease);
}

.page-about .tl-item--now::before {
  background: var(--cyan);
  box-shadow: 0 0 0 5px rgba(36, 224, 206, 0.16);
}

.page-about .tl-ver {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 15px;
  letter-spacing: 0.02em;
  color: var(--cyan);
}

.page-about .tl-body {
  padding-bottom: 4px;
}

.page-about .tl-stage {
  display: block;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.08em;
  color: var(--muted);
  margin-bottom: 6px;
}

.page-about .tl-body h3 {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 17px;
  line-height: 1.4;
  color: var(--text);
}

.page-about .tl-body p {
  margin: 0;
  max-width: 58ch;
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
  transition: color 180ms var(--ease);
}

.page-about .tl-item:hover .tl-body p,
.page-about .tl-item:focus-within .tl-body p {
  color: var(--text);
}

.page-about .tl-item:hover .tl-ver,
.page-about .tl-item:focus-within .tl-ver {
  color: var(--cyan-soft);
}

/* ---------- 覆盖 ---------- */
.page-about .about-reach {
  padding: 48px 0;
  border-top: 1px solid var(--line);
}

.page-about .reach-stats {
  display: grid;
  gap: 16px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .reach-stats li {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 22px 20px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--line);
  background: linear-gradient(160deg, rgba(36, 224, 206, 0.1), rgba(18, 48, 71, 0.7) 55%);
}

.page-about .reach-num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(36px, 10vw, 58px);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--cyan);
}

.page-about .reach-unit {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--amber);
}

.page-about .reach-desc {
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--muted);
}

.page-about .reach-foot {
  margin: 22px 0 0;
  padding: 14px 18px;
  border-left: 3px solid var(--cyan);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  background: rgba(18, 48, 71, 0.6);
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--muted);
}

/* ---------- 收束 ---------- */
.page-about .about-keep {
  padding: 52px 0 0;
  border-top: 1px solid var(--line);
}

.page-about .keep-inner {
  display: grid;
  gap: 28px;
  padding: 28px 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: rgba(7, 19, 31, 0.72);
}

.page-about .keep-copy .eyebrow {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--amber);
}

.page-about .keep-copy h2 {
  margin: 0 0 16px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(24px, 5vw, 38px);
  line-height: 1.24;
  color: var(--text);
}

.page-about .keep-copy p {
  margin: 0 0 14px;
  font-size: 15px;
  line-height: 1.85;
  color: var(--text);
}

.page-about .keep-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-content: start;
}

.page-about .keep-actions .btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 22px;
  border-radius: var(--pill);
  border: 1px solid var(--line);
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 15px;
  text-decoration: none;
  transition: border-color 180ms var(--ease), background-color 180ms var(--ease), color 180ms var(--ease);
}

.page-about .keep-actions .btn-primary {
  background: var(--cyan);
  border-color: var(--cyan);
  color: var(--ink-900);
}

.page-about .keep-actions .btn-primary:hover,
.page-about .keep-actions .btn-primary:focus-visible {
  background: var(--cyan-soft);
  border-color: var(--cyan-soft);
}

.page-about .keep-actions .btn-amber {
  background: transparent;
  border-color: var(--amber);
  color: var(--amber);
}

.page-about .keep-actions .btn-amber:hover,
.page-about .keep-actions .btn-amber:focus-visible {
  background: var(--amber);
  color: #2a1a00;
}

.page-about .keep-actions .btn-ghost {
  background: transparent;
  color: var(--muted);
}

.page-about .keep-actions .btn-ghost:hover,
.page-about .keep-actions .btn-ghost:focus-visible {
  border-color: var(--cyan);
  color: var(--cyan-soft);
}

.page-about .keep-note {
  flex-basis: 100%;
  margin: 4px 0 0;
  font-size: 12.5px;
  line-height: 1.8;
  color: var(--muted);
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .about-facts {
    grid-template-columns: repeat(3, 1fr);
  }

  .page-about .about-facts li {
    flex-direction: column;
    align-items: flex-start;
    gap: 6px;
  }

  .page-about .entry-map {
    grid-template-columns: repeat(2, 1fr);
  }

  .page-about .reach-stats {
    grid-template-columns: repeat(3, 1fr);
  }

  .page-about .keep-inner {
    grid-template-columns: 1.15fr 0.85fr;
    padding: 36px 34px;
  }

  .page-about .timeline {
    padding-left: 26px;
  }

  .page-about .tl-item {
    grid-template-columns: 64px 1fr;
    gap: 20px;
    padding-bottom: 36px;
  }
}

@media (min-width: 960px) {
  .page-about {
    background-size: 140px 140px;
  }

  .page-about .about-hero {
    grid-template-columns: 1.05fr 0.95fr;
    gap: 44px;
    align-items: center;
    padding: 36px 0 72px;
  }

  .page-about .about-hero .lede {
    font-size: 17px;
  }

  .page-about .story-grid {
    grid-template-columns: 1.35fr 0.65fr;
    gap: 48px;
  }

  .page-about .entry-map {
    grid-template-columns: repeat(3, 1fr);
  }

  .page-about .team-grid {
    grid-template-columns: 1.1fr 0.9fr;
    gap: 34px;
    align-items: start;
  }

  .page-about .reach-stats {
    gap: 20px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .entry-map-item,
  .page-about .tl-body p,
  .page-about .tl-ver,
  .page-about .team-panel,
  .page-about .keep-actions .btn {
    transition: none;
  }

  .page-about .entry-map-item:hover,
  .page-about .entry-map-item:focus-within {
    transform: none;
  }
}