.page-about {
  --about-border: 1px solid var(--mist);
  --about-space: clamp(30px, 5.5vw, 68px);
  background: var(--chalk);
  color: var(--ink);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(22px, 5vw, 40px) 0 clamp(34px, 6vw, 76px);
  color: var(--chalk);
  background:
    radial-gradient(120% 95% at 88% -10%, rgba(31, 122, 77, 0.62), transparent 62%),
    radial-gradient(80% 70% at 0% 110%, rgba(14, 59, 40, 0.85), transparent 60%),
    var(--ink);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image: repeating-linear-gradient(115deg, rgba(255, 255, 255, 0.05) 0 2px, transparent 2px 16px);
}

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

.page-about .about-hero .breadcrumbs {
  font-size: 12.5px;
  letter-spacing: 0.04em;
  color: var(--mist);
}

.page-about .about-hero .breadcrumbs a {
  color: var(--chalk);
  text-decoration: none;
  border-bottom: 1px solid rgba(255, 255, 255, 0.35);
}

.page-about .about-hero .breadcrumbs a:hover,
.page-about .about-hero .breadcrumbs a:focus-visible {
  border-bottom-color: var(--signal);
}

.page-about .about-hero .crumb-sep {
  margin: 0 8px;
  color: var(--concrete-mid);
}

.page-about .hero-kicker {
  display: inline-block;
  margin: clamp(18px, 4vw, 34px) 0 0;
  padding-left: 10px;
  border-left: 3px solid var(--signal);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--whistle);
}

.page-about .hero-title {
  margin: 14px 0 0;
  max-width: 22ch;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(31px, 7.4vw, 74px);
  line-height: 1.06;
  letter-spacing: -0.02em;
}

.page-about .hero-accent {
  color: var(--whistle);
}

.page-about .hero-lede {
  margin: clamp(16px, 2.6vw, 24px) 0 0;
  max-width: 60ch;
  font-size: clamp(15px, 1.7vw, 17.5px);
  line-height: 1.78;
  color: var(--mist);
}

.page-about .hero-figures {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  margin-top: clamp(24px, 4vw, 40px);
  border-top: 1px solid rgba(255, 255, 255, 0.22);
  border-bottom: 1px solid rgba(255, 255, 255, 0.22);
}

.page-about .hero-fig {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 14px 10px 16px 0;
}

.page-about .hero-fig + .hero-fig {
  padding-left: 12px;
  border-left: 1px solid rgba(255, 255, 255, 0.16);
}

.page-about .hero-fig-num {
  font-size: clamp(26px, 5.4vw, 44px);
  line-height: 1;
  font-weight: 600;
  color: var(--paper);
}

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

.page-about .hero-next {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px 14px;
  margin: clamp(20px, 3.4vw, 30px) 0 0;
  font-size: 13px;
}

.page-about .hero-next .mono {
  letter-spacing: 0.14em;
  color: var(--concrete-mid);
}

.page-about .hero-next a {
  color: var(--whistle);
  text-decoration: none;
  border-bottom: 2px solid var(--signal);
  padding-bottom: 2px;
}

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

/* ---------- 章节骨架 ---------- */
.page-about .chapter {
  padding: var(--about-space) 0;
  border-top: 3px solid var(--pitch);
}

.page-about .chapter:nth-of-type(even) {
  background: var(--paper);
}

.page-about .section-head {
  max-width: 68ch;
}

.page-about .section-index {
  display: inline-block;
  padding-left: 9px;
  border-left: 3px solid var(--signal);
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--pitch);
}

.page-about .section-title {
  margin: 10px 0 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(24px, 4.3vw, 42px);
  line-height: 1.16;
  letter-spacing: -0.01em;
  color: var(--ink);
}

.page-about .section-lede {
  margin: 12px 0 0;
  font-size: clamp(14.5px, 1.6vw, 16.5px);
  line-height: 1.75;
  color: var(--concrete-mid);
}

.page-about .chapter p {
  font-size: clamp(15px, 1.55vw, 16.5px);
  line-height: 1.8;
  color: var(--concrete-dark);
}

.page-about .chapter p + p {
  margin-top: 14px;
}

/* ---------- 01 起点 ---------- */
.page-about .origin-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(22px, 4vw, 42px);
  margin-top: clamp(22px, 3.6vw, 34px);
  align-items: start;
}

.page-about .origin-text p:first-child {
  margin-top: 0;
}

/* ---------- 02 资料层级 ---------- */
.page-about .layers-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(22px, 4vw, 40px);
  margin-top: clamp(22px, 3.6vw, 34px);
  align-items: start;
}

.page-about .layer-stack {
  display: grid;
  gap: 10px;
}

.page-about .layer {
  background: var(--paper);
  border: var(--about-border);
  border-left: 4px solid var(--pitch);
  transition: border-color 150ms ease, transform 150ms ease;
}

.page-about .chapter:nth-of-type(even) .layer {
  background: var(--chalk);
}

.page-about .layer:hover,
.page-about .layer:focus-within {
  border-left-color: var(--signal);
  transform: translateY(-2px);
}

.page-about .layer[open] {
  border-left-color: var(--signal);
}

.page-about .layer summary {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 4px 12px;
  padding: 14px 16px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .layer summary:focus-visible {
  outline: 2px solid var(--whistle);
  outline-offset: -4px;
  box-shadow: 0 0 0 4px var(--signal);
}

.page-about .layer-num {
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--pitch);
}

.page-about .layer-name {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(17px, 2.1vw, 21px);
  color: var(--ink);
}

.page-about .layer-hint {
  margin-left: auto;
  font-size: 12.5px;
  color: var(--concrete-mid);
}

.page-about .layer-body {
  padding: 0 16px 15px;
}

.page-about .layer-body p {
  margin: 0;
  padding-top: 12px;
  border-top: 1px solid var(--mist);
  font-size: 14.8px;
  line-height: 1.78;
}

/* ---------- 03 编辑与数据 ---------- */
.page-about .editor-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(22px, 4vw, 38px);
  margin-top: clamp(22px, 3.6vw, 34px);
  align-items: start;
}

.page-about .data-strip {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  border-top: 4px solid var(--ink);
  background: var(--chalk);
}

.page-about .chapter:nth-of-type(even) .data-strip {
  background: var(--chalk);
}

.page-about .data-strip .data-cell {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 15px 14px 17px;
  border-bottom: 1px solid var(--mist);
  border-right: 1px solid var(--mist);
}

.page-about .data-strip .data-cell:nth-child(even) {
  border-right: 0;
}

.page-about .data-strip .data-value {
  font-size: clamp(20px, 3.6vw, 27px);
  line-height: 1.1;
  font-weight: 600;
  color: var(--pitch);
}

.page-about .data-strip .data-label {
  font-size: 12.5px;
  line-height: 1.5;
  color: var(--concrete-mid);
}

/* ---------- 04 版本时间线 ---------- */
.page-about .timeline {
  position: relative;
  margin: clamp(24px, 4vw, 38px) 0 0;
  padding: 0 0 0 26px;
  list-style: none;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: var(--concrete-mid);
}

.page-about .timeline-item {
  position: relative;
  padding-bottom: clamp(18px, 3vw, 28px);
}

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

.page-about .timeline-item::before {
  content: "";
  position: absolute;
  left: -25px;
  top: 5px;
  width: 11px;
  height: 11px;
  box-sizing: border-box;
  background: var(--chalk);
  border: 2px solid var(--pitch);
  transition: background-color 150ms ease, border-color 150ms ease;
}

.page-about .timeline-item:hover::before,
.page-about .timeline-item:focus-within::before {
  background: var(--signal);
  border-color: var(--signal);
}

.page-about .timeline-version {
  margin: 0;
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--pitch);
  transition: color 150ms ease;
}

.page-about .timeline-item:hover .timeline-version {
  color: var(--signal);
}

.page-about .timeline-title {
  margin: 6px 0 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(17px, 2.2vw, 22px);
  line-height: 1.3;
  color: var(--ink);
}

.page-about .timeline-note {
  margin: 6px 0 0;
  max-width: 60ch;
  font-size: 14.8px;
  line-height: 1.8;
  color: var(--concrete-mid);
  transition: color 150ms ease;
}

.page-about .timeline-item:hover .timeline-note {
  color: var(--concrete-dark);
}

/* ---------- 05 共建 ---------- */
.page-about .clubs-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(22px, 4vw, 40px);
  margin-top: clamp(22px, 3.6vw, 34px);
  align-items: start;
}

.page-about .club-wall {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 22px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .club-tag {
  display: inline-block;
  padding: 8px 13px;
  border: 1px solid var(--concrete-mid);
  background: var(--paper);
  font-size: 13.5px;
  font-weight: 500;
  line-height: 1.2;
  color: var(--ink);
  text-decoration: none;
  transition: background-color 150ms ease, color 150ms ease, border-color 150ms ease;
}

.page-about .club-tag:hover {
  background: var(--ink);
  border-color: var(--signal);
  color: var(--chalk);
}

.page-about .club-tag:focus-visible {
  outline: 2px solid var(--whistle);
  outline-offset: 2px;
  box-shadow: 0 0 0 4px var(--signal);
}

/* ---------- 06 主张与行动 ---------- */
.page-about .belief-list {
  margin: clamp(22px, 3.6vw, 34px) 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 1px;
  background: var(--mist);
  border-top: 1px solid var(--mist);
  border-bottom: 1px solid var(--mist);
}

.page-about .belief-item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: clamp(12px, 3vw, 26px);
  padding: 18px 16px;
  background: var(--paper);
}

.page-about .belief-num {
  font-size: clamp(18px, 3vw, 24px);
  line-height: 1.1;
  color: var(--signal);
}

.page-about .belief-title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(16px, 2vw, 20px);
  color: var(--ink);
}

.page-about .belief-body p {
  margin: 6px 0 0;
  max-width: 62ch;
  font-size: 14.8px;
  line-height: 1.78;
  color: var(--concrete-mid);
}

.page-about .about-cta {
  margin-top: clamp(26px, 4vw, 40px);
  padding: clamp(20px, 3.4vw, 30px);
  background: var(--concrete-dark);
  color: var(--chalk);
  border-left: 5px solid var(--pitch);
}

.page-about .about-cta-text {
  margin: 0 0 16px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(19px, 2.8vw, 26px);
  line-height: 1.3;
  color: var(--paper);
}

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

.page-about .about-cta .btn-ghost {
  color: var(--chalk);
  border-color: var(--mist);
}

.page-about .about-cta .btn-ghost:hover,
.page-about .about-cta .btn-ghost:focus-visible {
  color: var(--ink);
  background: var(--whistle);
  border-color: var(--whistle);
}

/* ---------- 图片框 ---------- */
.page-about .media-frame {
  position: relative;
  margin: 0;
  border: 1px solid var(--mist);
  background: var(--concrete-dark);
}

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

.page-about .media-caption {
  padding: 10px 12px;
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--chalk);
  background: var(--concrete-dark);
}

/* ---------- 断点 ---------- */
@media (min-width: 720px) {
  .page-about .hero-fig {
    padding: 18px 16px 20px 0;
  }

  .page-about .layer summary {
    flex-wrap: nowrap;
    padding: 16px 20px;
  }

  .page-about .layer-hint {
    margin-left: auto;
  }

  .page-about .layer-body {
    padding: 0 20px 18px;
  }

  .page-about .belief-item {
    grid-template-columns: 60px minmax(0, 1fr);
    padding: 22px 24px;
  }
}

@media (min-width: 900px) {
  .page-about .origin-grid {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.92fr);
  }

  .page-about .layers-grid {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
  }

  .page-about .editor-grid {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
  }

  .page-about .clubs-grid {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
  }

  .page-about .layer:nth-child(2) {
    margin-left: 20px;
  }

  .page-about .layer:nth-child(3) {
    margin-left: 40px;
  }

  .page-about .layer:nth-child(4) {
    margin-left: 60px;
  }

  .page-about .timeline {
    padding-left: 34px;
  }

  .page-about .timeline::before {
    left: 8px;
  }

  .page-about .timeline-item::before {
    left: -33px;
  }
}

@media (min-width: 1180px) {
  .page-about .hero-title {
    max-width: 18ch;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .layer,
  .page-about .layer:hover,
  .page-about .layer:focus-within {
    transition: none;
    transform: none;
  }

  .page-about .club-tag,
  .page-about .timeline-item::before,
  .page-about .timeline-version,
  .page-about .timeline-note {
    transition: none;
  }
}
<<<PAGE_CSS_END>>>