.page-about {
  --rail-w: 96px;
  --chapter-gap: clamp(24px, 4vw, 56px);
  background: var(--ink-900);
  color: var(--paper-0);
  font-family: var(--font-body);
  padding-bottom: clamp(48px, 8vw, 96px);
  overflow-x: hidden;
}

.page-about .breadcrumbs {
  margin: 0 0 clamp(20px, 3vw, 32px);
  font-size: 0.8rem;
  color: var(--muted);
}

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

.page-about .breadcrumbs li {
  display: flex;
  align-items: center;
  gap: 8px;
}

.page-about .breadcrumbs li::after {
  content: "/";
  color: var(--ink-700);
}

.page-about .breadcrumbs li:last-child::after {
  content: "";
}

.page-about .breadcrumbs a {
  color: var(--muted);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--dur) ease, border-color var(--dur) ease;
}

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

/* ---------- 首屏拼贴 ---------- */
.page-about .about-hero {
  display: grid;
  gap: clamp(28px, 4vw, 48px);
  padding-bottom: clamp(36px, 5vw, 64px);
}

.page-about .hero-kicker {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin: 0 0 16px;
  font-family: var(--font-num);
  font-size: 0.78rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .hero-kicker__dot {
  width: 8px;
  height: 8px;
  background: var(--signal);
  display: inline-block;
}

.page-about h1 {
  margin: 0 0 20px;
  font-family: var(--font-title);
  font-weight: 700;
  font-size: clamp(2.1rem, 5.6vw, 3.6rem);
  line-height: 1.06;
  letter-spacing: -0.01em;
  color: var(--paper-0);
}

.page-about .hero-lede {
  margin: 0;
  max-width: 46ch;
  font-size: clamp(0.95rem, 1.4vw, 1.08rem);
  line-height: 1.8;
  color: var(--paper-1);
}

.page-about .hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.page-about .hero-tiles {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
}

.page-about .tile {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 10px;
  padding: 16px;
  min-height: 128px;
  background: var(--ink-800);
  border: 1px solid var(--ink-700);
  transition: border-color var(--dur) ease, background-color var(--dur) ease;
}

.page-about .tile:hover {
  border-color: var(--cyan);
}

.page-about .tile--accent {
  background: var(--signal);
  border-color: var(--signal);
  color: var(--ink-900);
}

.page-about .tile--accent:hover {
  background: var(--paper-0);
  border-color: var(--paper-0);
}

.page-about .tile--line {
  background: transparent;
  border-style: dashed;
}

.page-about .tile__num {
  font-family: var(--font-num);
  font-size: clamp(1.9rem, 4.6vw, 2.9rem);
  line-height: 1;
  letter-spacing: -0.02em;
}

.page-about .tile__label {
  font-size: 0.76rem;
  line-height: 1.6;
  color: var(--muted);
}

.page-about .tile--accent .tile__label {
  color: rgba(7, 20, 38, 0.78);
}

/* ---------- 主体骨架 ---------- */
.page-about .about-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
}

.page-about .rail {
  display: flex;
  margin-bottom: 8px;
}

.page-about .rail__inner {
  display: flex;
  align-items: center;
  gap: 12px;
  width: 100%;
  padding: 10px 0;
  border-top: 1px solid var(--ink-700);
  border-bottom: 1px solid var(--ink-700);
}

.page-about .rail__label {
  font-size: 0.68rem;
  letter-spacing: 0.1em;
  color: var(--muted);
}

.page-about .rail__value {
  font-family: var(--font-num);
  font-size: 0.86rem;
  color: var(--signal);
}

.page-about .rail__line {
  flex: 1;
  height: 1px;
  background: var(--ink-700);
}

/* ---------- 章节 ---------- */
.page-about .chapter {
  padding: clamp(36px, 6vw, 76px) 0;
  border-top: 1px solid var(--ink-700);
}

.page-about .chapter:first-child {
  border-top: 0;
}

.page-about .chapter-head {
  display: flex;
  align-items: baseline;
  gap: 14px;
  margin-bottom: clamp(18px, 2.5vw, 28px);
}

.page-about .chapter-num {
  margin: 0;
  font-family: var(--font-num);
  font-size: 0.82rem;
  letter-spacing: 0.1em;
  color: var(--signal);
  flex: none;
}

.page-about .chapter h2 {
  margin: 0;
  font-family: var(--font-title);
  font-weight: 700;
  font-size: clamp(1.5rem, 3.4vw, 2.3rem);
  line-height: 1.16;
  letter-spacing: -0.01em;
  color: var(--paper-0);
}

.page-about .chapter-lede {
  margin: 0 0 clamp(18px, 2.5vw, 26px);
  max-width: 60ch;
  font-size: 0.95rem;
  line-height: 1.8;
  color: var(--paper-1);
}

.page-about .prose p,
.page-about .chapter-body > p {
  margin: 0 0 16px;
  font-size: 0.95rem;
  line-height: 1.85;
  color: var(--paper-1);
}

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

.page-about .note {
  margin: clamp(18px, 2.5vw, 26px) 0 0;
  padding-left: 14px;
  border-left: 2px solid var(--ink-700);
  font-size: 0.8rem;
  line-height: 1.75;
  color: var(--muted);
}

/* ---------- 媒体 ---------- */
.page-about .media-figure {
  margin: clamp(20px, 3vw, 30px) 0 0;
}

.page-about .media-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border: 1px solid var(--ink-700);
}

/* ---------- 原则卡片 ---------- */
.page-about .principles {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
}

.page-about .principle {
  padding: clamp(18px, 2.4vw, 26px);
  background: var(--ink-800);
  border: 1px solid var(--ink-700);
  border-left-width: 3px;
  transition: background-color var(--dur) ease, transform var(--dur) ease;
}

.page-about .principle:hover {
  background: var(--ink-700);
}

.page-about .principle--cyan {
  border-left-color: var(--cyan);
}

.page-about .principle--signal {
  border-left-color: var(--signal);
}

.page-about .principle--ok {
  border-left-color: var(--ok);
}

.page-about .principle__tag {
  margin: 0 0 10px;
  font-family: var(--font-num);
  font-size: 0.7rem;
  letter-spacing: 0.14em;
  color: var(--muted);
}

.page-about .principle h3 {
  margin: 0 0 10px;
  font-family: var(--font-title);
  font-size: 1.2rem;
  line-height: 1.3;
  color: var(--paper-0);
}

.page-about .principle p {
  margin: 0;
  font-size: 0.86rem;
  line-height: 1.8;
  color: var(--paper-1);
}

/* ---------- 时间线 ---------- */
.page-about .chapter-body--split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(22px, 3.4vw, 40px);
}

.page-about .timeline {
  list-style: none;
  margin: 0;
  padding: 0 0 0 26px;
  position: relative;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 8px;
  bottom: 14px;
  width: 1px;
  background: var(--ink-700);
}

.page-about .stage {
  position: relative;
  padding-bottom: 22px;
}

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

.page-about .stage::before {
  content: "";
  position: absolute;
  left: -26px;
  top: 6px;
  width: 9px;
  height: 9px;
  background: var(--ink-900);
  border: 1px solid var(--cyan);
  transition: background-color var(--dur) ease, box-shadow var(--dur) ease;
}

.page-about .stage[open]::before,
.page-about .stage:hover::before {
  background: var(--cyan);
  box-shadow: 0 0 0 4px rgba(53, 240, 208, 0.16);
}

.page-about .stage summary {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px;
  cursor: pointer;
  list-style: none;
  padding: 2px 0;
}

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

.page-about .stage__tag {
  font-family: var(--font-num);
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  color: var(--signal);
}

.page-about .stage__title {
  font-family: var(--font-title);
  font-size: 1.16rem;
  color: var(--paper-0);
}

.page-about .stage summary:hover .stage__title,
.page-about .stage summary:focus-visible .stage__title {
  color: var(--cyan);
}

.page-about .stage p {
  margin: 10px 0 0;
  font-size: 0.86rem;
  line-height: 1.8;
  color: var(--muted);
  max-width: 44ch;
}

/* ---------- 团队面板 ---------- */
.page-about .team-panel {
  background: var(--paper-0);
  color: var(--ink-900);
  padding: clamp(16px, 2.6vw, 32px);
}

.page-about .team-row {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: clamp(14px, 2.4vw, 28px);
  align-items: start;
  padding: clamp(14px, 2vw, 22px) 0;
  border-bottom: 1px solid var(--paper-1);
}

.page-about .team-row:first-child {
  padding-top: 0;
}

.page-about .team-row:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}

.page-about .team-num {
  font-family: var(--font-num);
  font-size: clamp(2rem, 5vw, 3rem);
  line-height: 0.9;
  color: var(--signal);
  letter-spacing: -0.03em;
}

.page-about .team-copy h3 {
  margin: 0 0 8px;
  font-family: var(--font-title);
  font-size: 1.12rem;
  color: var(--ink-900);
}

.page-about .team-copy p {
  margin: 0;
  font-size: 0.86rem;
  line-height: 1.8;
  color: #2a3f57;
}

/* ---------- 测试矩阵 ---------- */
.page-about .matrix-copy p {
  margin: 0 0 20px;
  font-size: 0.95rem;
  line-height: 1.85;
  color: var(--paper-1);
}

.page-about .matrix-facts {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 2px;
}

.page-about .matrix-facts li {
  display: grid;
  grid-template-columns: 3.2em minmax(0, 1fr);
  gap: 12px;
  align-items: baseline;
  padding: 10px 12px;
  background: var(--ink-800);
  border-left: 2px solid var(--ink-700);
  font-size: 0.84rem;
  line-height: 1.65;
  color: var(--muted);
  transition: border-color var(--dur) ease, color var(--dur) ease;
}

.page-about .matrix-facts li:hover {
  border-left-color: var(--cyan);
  color: var(--paper-1);
}

.page-about .matrix-facts__num {
  font-family: var(--font-num);
  font-size: 1.1rem;
  color: var(--cyan);
}

.page-about .matrix-visual {
  display: grid;
  gap: 10px;
}

.page-about .matrix-dots {
  width: 100%;
  aspect-ratio: 7 / 3;
  background-image: radial-gradient(circle, var(--cyan) 0 2px, transparent 2px);
  background-size: calc(100% / 14) calc(100% / 3);
  background-position: center;
  opacity: 0.55;
}

.page-about .matrix-visual .media-figure {
  margin: 0;
}

.page-about .matrix-caption {
  margin: 0;
  font-size: 0.74rem;
  line-height: 1.6;
  color: var(--muted);
}

/* ---------- 合作伙伴 ---------- */
.page-about .partner-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
  margin-top: clamp(18px, 2.6vw, 26px);
}

.page-about .partner-card {
  padding: clamp(16px, 2.2vw, 24px);
  border: 1px solid var(--ink-700);
  background: linear-gradient(180deg, rgba(23, 50, 79, 0.55), rgba(7, 20, 38, 0));
  transition: border-color var(--dur) ease;
}

.page-about .partner-card:hover {
  border-color: var(--signal);
}

.page-about .partner-card__num {
  display: block;
  font-family: var(--font-num);
  font-size: clamp(1.7rem, 3.4vw, 2.3rem);
  line-height: 1;
  color: var(--signal);
  margin-bottom: 10px;
}

.page-about .partner-card__unit {
  font-size: 0.6em;
  margin-left: 2px;
}

.page-about .partner-card h3 {
  margin: 0 0 8px;
  font-family: var(--font-title);
  font-size: 1.02rem;
  color: var(--paper-0);
}

.page-about .partner-card p {
  margin: 0;
  font-size: 0.82rem;
  line-height: 1.75;
  color: var(--muted);
}

/* ---------- 复盘节奏 ---------- */
.page-about .review-strip {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 8px;
  margin-top: clamp(16px, 2.4vw, 24px);
}

.page-about .review-step {
  padding: 16px 18px;
  background: var(--ink-800);
  border-top: 2px solid var(--ink-700);
  transition: border-top-color var(--dur) ease, background-color var(--dur) ease;
}

.page-about .review-step:hover {
  border-top-color: var(--cyan);
  background: var(--ink-700);
}

.page-about .review-step__time {
  display: block;
  font-family: var(--font-num);
  font-size: 0.86rem;
  color: var(--cyan);
  margin-bottom: 8px;
}

.page-about .review-step p {
  margin: 0;
  font-size: 0.84rem;
  line-height: 1.75;
  color: var(--paper-1);
}

.page-about .review-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(18px, 2.6vw, 26px);
}

/* ---------- 结尾 ---------- */
.page-about .about-cta {
  margin-top: clamp(24px, 4vw, 48px);
  padding: clamp(24px, 4vw, 44px) clamp(18px, 3vw, 36px);
  background: var(--ink-800);
  border: 1px solid var(--ink-700);
  border-top: 3px solid var(--signal);
}

.page-about .about-cta h2 {
  margin: 0 0 14px;
  font-family: var(--font-title);
  font-size: clamp(1.4rem, 3vw, 2rem);
  line-height: 1.2;
  color: var(--paper-0);
}

.page-about .about-cta p {
  margin: 0;
  max-width: 62ch;
  font-size: 0.9rem;
  line-height: 1.85;
  color: var(--paper-1);
}

.page-about .cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 24px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .principles {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

  .page-about .review-strip {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .matrix-dots {
    aspect-ratio: 7 / 2;
  }
}

@media (min-width: 960px) {
  .page-about .about-hero {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: start;
  }

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

  .page-about .tile {
    min-height: 152px;
    padding: 20px;
  }

  .page-about .about-shell {
    grid-template-columns: var(--rail-w) minmax(0, 1fr);
    gap: var(--chapter-gap);
    align-items: start;
  }

  .page-about .rail {
    margin-bottom: 0;
    height: 100%;
  }

  .page-about .rail__inner {
    position: sticky;
    top: 104px;
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
    padding: 16px 0 0;
    border-top: 1px solid var(--ink-700);
    border-bottom: 0;
  }

  .page-about .rail__line {
    width: 100%;
    flex: none;
    margin: 8px 0;
  }

  .page-about .chapter {
    display: grid;
    grid-template-columns: minmax(0, 4fr) minmax(0, 8fr);
    gap: clamp(24px, 3.4vw, 48px);
    align-items: start;
  }

  .page-about .chapter-head {
    display: block;
    margin-bottom: 0;
    position: sticky;
    top: 112px;
  }

  .page-about .chapter-num {
    display: block;
    margin-bottom: 12px;
  }

  .page-about .chapter-body--split {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    align-items: start;
  }

  .page-about .chapter-body--split .media-figure {
    margin-top: 0;
  }

  .page-about .matrix-copy {
    align-self: start;
  }

  .page-about .team-row {
    grid-template-columns: 4.6em minmax(0, 1fr);
  }

  .page-about .about-cta {
    margin-left: 0;
  }
}

@media (min-width: 1200px) {
  .page-about .tile__label {
    font-size: 0.8rem;
  }

  .page-about .chapter-body--split {
    gap: clamp(28px, 3vw, 52px);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .tile,
  .page-about .principle,
  .page-about .stage::before,
  .page-about .matrix-facts li,
  .page-about .partner-card,
  .page-about .review-step,
  .page-about .breadcrumbs a {
    transition: none;
  }
}
<<<END>>>