.page-about {
  --about-lead: 1.0625rem;
}

.page-about .breadcrumb {
  padding-top: 18px;
}

.page-about .about-hero {
  display: grid;
  gap: 28px;
  padding-top: 22px;
  padding-bottom: 46px;
}

.page-about .hero-copy h1 {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(32px, 9vw, 58px);
  line-height: 1.04;
  letter-spacing: -.02em;
  color: var(--paper);
  margin: 12px 0 18px;
  transform: skewX(-2deg);
  transform-origin: left bottom;
}

.page-about .hero-lead {
  font-size: var(--about-lead);
  line-height: 1.78;
  color: var(--paper);
  margin: 0 0 14px;
  max-width: 34em;
}

.page-about .hero-sub {
  font-size: 15px;
  line-height: 1.75;
  color: var(--mist);
  margin: 0;
  max-width: 32em;
}

.page-about .hero-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px 22px;
  margin-top: 26px;
}

.page-about .hero-link {
  font-size: 14px;
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid var(--rule);
  padding-bottom: 2px;
}

.page-about .hero-visual {
  position: relative;
}

.page-about .hero-media {
  position: relative;
  margin: 0;
  background: var(--ink-3);
  border: 1px solid var(--rule);
  box-shadow: var(--shadow-paper);
}

.page-about .hero-media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 7 / 4;
  object-fit: cover;
}

.page-about .about-chapters {
  display: block;
}

.page-about .chapter {
  display: grid;
  gap: 12px;
  padding: 38px 0;
  border-top: 1px solid var(--rule);
}

.page-about .chapter-rail {
  display: flex;
  align-items: baseline;
  gap: 12px;
}

.page-about .rail-num {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .18em;
  color: var(--cyan);
}

.page-about .rail-label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .26em;
  color: var(--mist);
}

.page-about .chapter-body {
  min-width: 0;
}

.page-about .chapter h2 {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(23px, 5.4vw, 38px);
  line-height: 1.16;
  letter-spacing: -.01em;
  color: var(--paper);
  margin: 0 0 16px;
}

.page-about .chapter p {
  font-size: 16px;
  line-height: 1.78;
  color: var(--paper);
  margin: 0 0 16px;
  max-width: 34em;
}

.page-about .chapter-lead {
  color: var(--paper);
  font-size: var(--about-lead);
}

.page-about .chapter-lead::first-letter {
  color: var(--cyan);
}

.page-about .inline-link {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid var(--rule);
}

.page-about .inline-link:hover,
.page-about .inline-link:focus-visible {
  border-bottom-color: var(--cyan);
}

/* 原则：双色分隔带 + 纸签编号 */
.page-about .principles {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  gap: 16px;
}

.page-about .principle {
  position: relative;
  padding: 20px 18px 18px;
  background: var(--ink-3);
  border: 1px solid var(--rule);
  border-top: 3px solid var(--cyan);
}

.page-about .principle:nth-child(2) {
  border-top-color: var(--orange);
}

.page-about .principle:nth-child(3) {
  border-top-color: var(--paper);
}

.page-about .principle-num {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1;
  letter-spacing: .1em;
  color: var(--ink);
  background: var(--tag);
  padding: 4px 8px;
  transform: rotate(-1.5deg);
}

.page-about .principle h3 {
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 800;
  letter-spacing: -.01em;
  color: var(--paper);
  margin: 14px 0 8px;
}

.page-about .principle p {
  font-size: 15px;
  line-height: 1.72;
  color: var(--mist);
  margin: 0 0 14px;
  max-width: none;
}

.page-about .principle-link {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .05em;
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid var(--rule);
  padding-bottom: 2px;
}

.page-about .principle-link:hover,
.page-about .principle-link:focus-visible {
  border-bottom-color: var(--cyan);
}

/* 团队 */
.page-about .team-grid {
  display: grid;
  gap: 26px;
}

.page-about .team-copy {
  min-width: 0;
}

.page-about .roles {
  list-style: none;
  margin: 22px 0 20px;
  padding: 0;
  display: grid;
  gap: 16px;
  max-width: 34em;
}

.page-about .role-name {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .04em;
  color: var(--paper);
  margin-bottom: 8px;
}

.page-about .role-count {
  color: var(--cyan);
}

.page-about .role-bar {
  display: block;
  height: 6px;
  background: var(--ink);
  border: 1px solid var(--rule);
}

.page-about .role-fill {
  display: block;
  height: 100%;
  background: var(--neon);
}

.page-about .role:nth-child(1) .role-fill {
  width: 100%;
}

.page-about .role:nth-child(2) .role-fill {
  width: 55%;
}

.page-about .role:nth-child(3) .role-fill {
  width: 36%;
}

.page-about .team-media,
.page-about .milestone-media {
  position: relative;
  margin: 0;
  background: var(--ink-3);
  border: 1px solid var(--rule);
  box-shadow: var(--shadow-paper);
}

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

/* 时间线 */
.page-about .tl {
  list-style: none;
  margin: 26px 0 6px;
  padding: 0;
  display: grid;
  gap: 0;
}

.page-about .tl-node {
  position: relative;
  padding: 0 0 24px 22px;
  border-left: 1px solid var(--rule);
}

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

.page-about .tl-dot {
  position: absolute;
  left: -4px;
  top: 6px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--orange);
  box-shadow: 0 0 0 4px var(--orange-soft);
}

.page-about .tl-year {
  display: block;
  font-family: var(--font-mono);
  font-size: 15px;
  letter-spacing: .1em;
  color: var(--cyan);
  margin-bottom: 8px;
}

.page-about .tl-detail {
  max-width: 32em;
}

.page-about .tl-detail summary {
  cursor: pointer;
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 700;
  color: var(--paper);
  line-height: 1.4;
  list-style: none;
  border-bottom: 1px dashed var(--rule);
  padding-bottom: 4px;
}

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

.page-about .tl-detail summary::after {
  content: " ＋";
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--orange);
}

.page-about .tl-detail[open] summary::after {
  content: " −";
  color: var(--cyan);
}

.page-about .tl-detail .fold-body {
  font-size: 14px;
  line-height: 1.72;
  color: var(--mist);
  margin-top: 10px;
}

.page-about .milestone-media {
  margin-top: 30px;
}

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

/* 覆盖范围指标 */
.page-about .metrics {
  list-style: none;
  margin: 24px 0 22px;
  padding: 1px;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--rule);
  border: 1px solid var(--rule);
}

.page-about .metric {
  background: var(--ink-2);
  padding: 16px 14px;
  min-width: 0;
}

.page-about .metric:last-child {
  grid-column: 1 / -1;
}

.page-about .metric-num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(21px, 4.4vw, 30px);
  letter-spacing: -.01em;
  color: var(--cyan);
  line-height: 1.1;
}

.page-about .metric-label {
  display: block;
  margin-top: 8px;
  font-size: 13px;
  line-height: 1.55;
  color: var(--mist);
}

/* 合作 */
.page-about .coop {
  display: grid;
  gap: 16px;
  margin: 24px 0 22px;
}

.page-about .coop-card {
  background: var(--ink-2);
  border: 1px solid var(--rule);
  border-left: 3px solid var(--orange);
  padding: 20px 18px;
}

.page-about .coop-card h3 {
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 800;
  color: var(--paper);
  margin: 0 0 10px;
}

.page-about .coop-card p {
  font-size: 15px;
  line-height: 1.72;
  color: var(--mist);
  margin: 0;
  max-width: none;
}

/* 收尾 */
.page-about .closing {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  margin: 30px 0 56px;
  padding: 24px 20px;
  border: 1px solid var(--rule);
  background: linear-gradient(135deg, var(--ink-2), var(--ink-3));
  box-shadow: var(--shadow-paper);
}

.page-about .closing-text {
  margin: 0;
  font-size: 15px;
  line-height: 1.7;
  color: var(--paper);
  max-width: 30em;
}

.page-about .closing-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px 18px;
}

.page-about .closing-link {
  font-size: 14px;
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid var(--rule);
  padding-bottom: 2px;
}

@media (min-width: 760px) {
  .page-about .metrics {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }

  .page-about .metric:last-child {
    grid-column: auto;
  }

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

  .page-about .tl {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    position: relative;
    margin-top: 32px;
  }

  .page-about .tl::before {
    content: "";
    position: absolute;
    top: 10px;
    left: 4px;
    right: 6px;
    height: 1px;
    background: var(--neon);
    opacity: .55;
  }

  .page-about .tl-node {
    border-left: 0;
    padding: 0 18px 0 0;
  }

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

  .page-about .tl-dot {
    left: 0;
    top: 6px;
  }

  .page-about .tl-year,
  .page-about .tl-detail {
    margin-left: 20px;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: 52px;
    align-items: center;
    padding-top: 46px;
    padding-bottom: 74px;
  }

  .page-about .chapter {
    grid-template-columns: 104px minmax(0, 1fr);
    gap: 46px;
    padding: 62px 0;
  }

  .page-about .chapter-rail {
    flex-direction: column;
    align-items: flex-start;
    gap: 16px;
    position: sticky;
    top: 132px;
    align-self: start;
  }

  .page-about .rail-label {
    writing-mode: vertical-rl;
    text-orientation: mixed;
    letter-spacing: .34em;
  }

  .page-about .principles {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px;
  }

  .page-about .team-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 42px;
    align-items: start;
  }

  .page-about .milestone-media {
    max-width: 620px;
  }

  .page-about .closing {
    padding: 30px 28px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .hero-copy h1 {
    transform: none;
  }

  .page-about .principle-num {
    transform: none;
  }
}
<<<END>>>