.page-about {
  --about-index-w: 172px;
  --about-line: var(--line);
  padding-top: calc(var(--header-h) + 32px);
  padding-bottom: clamp(48px, 7vw, 96px);
  background:
    radial-gradient(120% 60% at 84% 0%, rgba(28, 26, 60, 0.85) 0%, rgba(6, 26, 36, 0) 62%),
    var(--bg);
  color: var(--fg);
  font-family: var(--font-sans);
  overflow-x: clip;
}

.page-about .mono {
  font-family: var(--font-mono);
  letter-spacing: 0.02em;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  isolation: isolate;
  padding-bottom: clamp(40px, 6vw, 76px);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -32px;
  right: -18vw;
  width: min(78vw, 780px);
  height: min(66vw, 560px);
  background: linear-gradient(135deg, var(--c-indigo) 8%, rgba(28, 26, 60, 0) 76%);
  clip-path: polygon(34% 0, 100% 0, 100% 100%, 0 74%);
  z-index: -1;
  opacity: 0.92;
  pointer-events: none;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: auto 0 0 0;
  height: 1px;
  background: linear-gradient(90deg, var(--c-coral), rgba(255, 107, 61, 0) 46%, var(--line-strong));
  z-index: -1;
}

.page-about .breadcrumbs {
  margin-bottom: clamp(20px, 3vw, 32px);
}

.page-about .hero-title {
  margin: 12px 0 0;
  font-size: clamp(2rem, 5.6vw, 4rem);
  font-weight: 300;
  line-height: 1.08;
  letter-spacing: -0.01em;
  max-width: 20ch;
}

.page-about .hero-title b {
  font-weight: 700;
  color: var(--c-coral);
}

.page-about .about-hero .lede {
  margin-top: clamp(20px, 3vw, 30px);
  max-width: 38ch;
  color: var(--muted);
}

.page-about .hero-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(32px, 5vw, 52px) 0 0;
  padding: 0;
  list-style: none;
  background: var(--line);
  border-block: 1px solid var(--line);
}

.page-about .hero-facts li {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 16px 14px;
  background: var(--bg);
}

.page-about .fact-num {
  font-family: var(--font-mono);
  font-size: clamp(1.25rem, 3vw, 1.75rem);
  font-weight: 700;
  color: var(--c-mist);
  line-height: 1.1;
}

.page-about .hero-facts li:first-child .fact-num {
  color: var(--c-coral);
}

.page-about .fact-label {
  font-size: var(--step-1);
  letter-spacing: 0.12em;
  color: var(--muted);
}

/* ---------- 骨架：窄索引 + 纵向流 ---------- */
.page-about .about-shell {
  display: block;
}

.page-about .about-index {
  display: none;
}

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

/* ---------- 章节 ---------- */
.page-about .chapter {
  position: relative;
  padding-block: clamp(44px, 6.5vw, 84px);
  border-top: 1px solid var(--line);
  overflow: clip;
}

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

.page-about .sec-num {
  position: absolute;
  top: clamp(24px, 4vw, 48px);
  right: -8px;
  font-family: var(--font-mono);
  font-size: clamp(4rem, 15vw, 8.5rem);
  font-weight: 300;
  line-height: 0.8;
  color: rgba(143, 163, 173, 0.1);
  pointer-events: none;
  user-select: none;
}

.page-about .chapter-title {
  margin: 10px 0 0;
  font-size: clamp(1.5rem, 3.6vw, 2.5rem);
  font-weight: 300;
  line-height: 1.22;
  max-width: 22ch;
}

.page-about .chapter-title::after {
  content: "";
  display: block;
  width: 42px;
  height: 2px;
  margin-top: 18px;
  background: var(--c-coral);
}

.page-about .chapter-lede {
  margin: clamp(16px, 2.4vw, 24px) 0 0;
  max-width: 38ch;
  font-size: var(--step-3);
  line-height: 1.75;
  color: var(--muted);
}

/* ---------- 01 团队构成 ---------- */
.page-about .team-grid {
  display: grid;
  gap: clamp(28px, 4vw, 48px);
  margin-top: clamp(28px, 4vw, 44px);
}

.page-about .ring {
  margin: 0;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(160deg, rgba(10, 46, 51, 0.72), rgba(6, 26, 36, 0.2));
  box-shadow: 0 18px 40px rgba(2, 9, 13, 0.45);
}

.page-about .ring svg {
  display: block;
  width: 100%;
  max-width: 260px;
  height: auto;
  margin: 0 auto;
}

.page-about .ring-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 18px;
  margin: 18px 0 0;
  padding: 0;
  list-style: none;
  font-size: var(--step-2);
  color: var(--muted);
}

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

.page-about .ring-legend .mono {
  color: var(--c-mist);
  font-weight: 700;
}

.page-about .dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  display: inline-block;
}

.page-about .dot-coral { background: var(--c-coral); }
.page-about .dot-verify { background: var(--c-verify); }
.page-about .dot-slate { background: var(--c-slate); }

.page-about .role-list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 1px;
  background: var(--line);
  border-block: 1px solid var(--line);
}

.page-about .role-item {
  padding: 22px 0;
  background: var(--bg);
}

.page-about .role-kicker {
  margin: 0 0 8px;
  font-size: var(--step-1);
  letter-spacing: 0.1em;
  color: var(--c-verify);
}

.page-about .role-item h3 {
  margin: 0 0 10px;
  font-size: var(--step-4);
  font-weight: 700;
  color: var(--c-mist);
}

.page-about .role-item p {
  margin: 0;
  max-width: 36ch;
  font-size: var(--step-3);
  line-height: 1.75;
  color: var(--muted);
}

/* ---------- 02 时间轴 ---------- */
.page-about .timeline-wrap {
  display: grid;
  gap: clamp(32px, 4vw, 52px);
  margin-top: clamp(28px, 4vw, 44px);
}

.page-about .tl {
  position: relative;
  margin: 0;
  padding: 0 0 0 30px;
  list-style: none;
}

.page-about .tl::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: linear-gradient(180deg, var(--c-verify), rgba(47, 211, 181, 0.12));
}

.page-about .tl-item {
  position: relative;
  padding: 0 0 26px;
  outline-offset: 6px;
}

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

.page-about .tl-item::before {
  content: "";
  position: absolute;
  left: -30px;
  top: 7px;
  width: 13px;
  height: 13px;
  border: 1px solid var(--c-verify);
  border-radius: 50%;
  background: var(--c-deep);
}

.page-about .tl-item:last-child::before {
  background: var(--c-verify);
  box-shadow: 0 0 0 4px rgba(47, 211, 181, 0.16);
}

.page-about .tl-year {
  margin: 0 0 6px;
  font-size: var(--step-2);
  color: var(--c-coral);
}

.page-about .tl-item h3 {
  margin: 0;
  font-size: var(--step-4);
  font-weight: 700;
  color: var(--c-mist);
}

.page-about .tl-more {
  max-height: 0;
  opacity: 0;
  overflow: hidden;
  transition: max-height 420ms var(--ease), opacity 320ms var(--ease);
}

.page-about .tl-more p {
  margin: 10px 0 0;
  max-width: 36ch;
  font-size: var(--step-3);
  line-height: 1.75;
  color: var(--muted);
}

.page-about .tl-item:hover .tl-more,
.page-about .tl-item:focus-within .tl-more,
.page-about .tl-item:focus .tl-more {
  max-height: 16em;
  opacity: 1;
}

.page-about .tl-photo {
  margin: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .tl-photo img,
.page-about .flow-figure img,
.page-about .tl-texture img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .tl-photo img {
  aspect-ratio: 3 / 2;
}

.page-about .tl-texture {
  margin: clamp(32px, 5vw, 56px) calc(-1 * clamp(16px, 4vw, 48px)) 0;
  border-radius: 0;
}

.page-about .tl-texture img {
  aspect-ratio: 8 / 3;
}

.page-about .media-caption {
  margin: 0;
  padding: 12px 14px;
  font-size: var(--step-2);
  color: var(--muted);
  border-top: 1px solid var(--line);
  background: rgba(2, 9, 13, 0.5);
}

/* ---------- 03 入库流程 ---------- */
.page-about .flow-figure {
  margin: clamp(28px, 4vw, 44px) 0 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: linear-gradient(150deg, rgba(28, 26, 60, 0.7), rgba(6, 26, 36, 0.3));
}

.page-about .flow-figure img {
  aspect-ratio: 4 / 3;
}

.page-about .pipe {
  display: grid;
  gap: 1px;
  margin: clamp(24px, 3.5vw, 36px) 0 0;
  padding: 0;
  list-style: none;
  background: var(--line);
  border-block: 1px solid var(--line);
}

.page-about .pipe-step {
  padding: 22px 0 24px;
  background: var(--bg);
}

.page-about .pipe-num {
  display: block;
  font-size: var(--step-1);
  letter-spacing: 0.16em;
  color: var(--c-verify);
}

.page-about .pipe-step h3 {
  margin: 10px 0 8px;
  font-size: var(--step-4);
  font-weight: 700;
  color: var(--c-mist);
}

.page-about .pipe-step p {
  margin: 0;
  max-width: 30ch;
  font-size: var(--step-2);
  line-height: 1.7;
  color: var(--muted);
}

/* ---------- 04 三条规矩 ---------- */
.page-about .codex {
  display: grid;
  gap: 16px;
  margin-top: clamp(28px, 4vw, 44px);
}

.page-about .codex-item {
  padding: 24px 20px 26px;
  border: 1px solid var(--line);
  border-left: 2px solid var(--c-coral);
  border-radius: var(--radius);
  background: linear-gradient(170deg, rgba(10, 46, 51, 0.62), rgba(6, 26, 36, 0.1));
}

.page-about .codex-item:nth-child(2) {
  border-left-color: var(--c-verify);
}

.page-about .codex-item:nth-child(3) {
  border-left-color: var(--c-wine);
}

.page-about .codex-tag {
  margin: 0 0 12px;
  font-size: var(--step-1);
  letter-spacing: 0.18em;
  color: var(--muted);
}

.page-about .codex-item h3 {
  margin: 0 0 10px;
  font-size: var(--step-5);
  font-weight: 700;
  color: var(--c-mist);
}

.page-about .codex-item p:last-child {
  margin: 0;
  font-size: var(--step-3);
  line-height: 1.75;
  color: var(--muted);
}

/* ---------- 05 使用场景 ---------- */
.page-about .scenes {
  display: grid;
  gap: 1px;
  margin: clamp(28px, 4vw, 44px) 0 0;
  padding: 0;
  list-style: none;
  background: var(--line);
  border-block: 1px solid var(--line);
}

.page-about .scene {
  padding: 26px 0 28px;
  background: var(--bg);
}

.page-about .scene-label {
  margin: 0 0 10px;
  font-size: var(--step-1);
  letter-spacing: 0.14em;
  color: var(--c-verify);
}

.page-about .scene h3 {
  margin: 0 0 10px;
  font-size: var(--step-4);
  font-weight: 700;
  color: var(--c-mist);
}

.page-about .scene p {
  margin: 0 0 16px;
  max-width: 38ch;
  font-size: var(--step-3);
  line-height: 1.75;
  color: var(--muted);
}

.page-about .scene-link {
  display: inline-block;
  font-size: var(--step-2);
  letter-spacing: 0.08em;
  color: var(--c-coral);
  text-decoration: none;
  border-bottom: 1px solid rgba(255, 107, 61, 0.4);
  padding-bottom: 2px;
  transition: color 220ms var(--ease), border-color 220ms var(--ease);
}

.page-about .scene-link:hover,
.page-about .scene-link:focus-visible {
  color: var(--c-verify);
  border-bottom-color: var(--c-verify);
}

/* ---------- 收尾 ---------- */
.page-about .about-outro {
  margin-top: clamp(44px, 6vw, 80px);
  padding: clamp(28px, 4vw, 44px) 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(155deg, var(--c-ink) 0%, rgba(10, 46, 51, 0.85) 100%);
}

.page-about .about-outro .chapter-lede {
  margin-bottom: 0;
}

.page-about .outro-links {
  display: grid;
  gap: 1px;
  margin: clamp(24px, 3.5vw, 36px) 0 0;
  padding: 0;
  list-style: none;
  background: var(--line-strong);
}

.page-about .outro-links a {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 16px 4px;
  background: var(--c-ink);
  text-decoration: none;
  transition: background 240ms var(--ease), padding-left 240ms var(--ease);
}

.page-about .outro-links a:hover,
.page-about .outro-links a:focus-visible {
  background: rgba(10, 46, 51, 0.9);
  padding-left: 10px;
}

.page-about .outro-name {
  font-size: var(--step-4);
  font-weight: 700;
  color: var(--c-mist);
}

.page-about .outro-desc {
  font-size: var(--step-2);
  color: var(--muted);
}

.page-about a:focus-visible,
.page-about .tl-item:focus-visible {
  outline: 2px solid var(--c-verify);
  outline-offset: 4px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 600px) {
  .page-about .hero-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .role-item,
  .page-about .pipe-step,
  .page-about .scene {
    padding-inline: 4px;
  }

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

@media (min-width: 860px) {
  .page-about .codex {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    align-items: start;
  }

  .page-about .codex-item:nth-child(2) {
    margin-top: 34px;
  }

  .page-about .codex-item:nth-child(3) {
    margin-top: -10px;
  }

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

  .page-about .pipe-step {
    padding: 26px 14px 28px;
  }

  .page-about .pipe-step:first-child {
    padding-left: 0;
  }

  .page-about .role-item {
    padding: 24px 24px 26px;
  }
}

@media (min-width: 1024px) {
  .page-about .about-shell {
    display: grid;
    grid-template-columns: var(--about-index-w) minmax(0, 1fr);
    gap: clamp(32px, 5vw, 72px);
    align-items: start;
  }

  .page-about .about-index {
    display: block;
    position: sticky;
    top: calc(var(--header-h) + 36px);
    align-self: start;
    padding-top: clamp(44px, 6.5vw, 84px);
  }

  .page-about .index-head {
    margin: 0 0 14px;
    font-size: var(--step-1);
    letter-spacing: 0.18em;
    color: var(--muted);
    text-transform: uppercase;
  }

  .page-about .index-list {
    margin: 0 0 24px;
    padding: 0;
    list-style: none;
    border-left: 1px solid var(--line);
  }

  .page-about .index-list li {
    margin: 0;
  }

  .page-about .index-list a {
    display: flex;
    align-items: baseline;
    gap: 10px;
    padding: 9px 0 9px 14px;
    margin-left: -1px;
    border-left: 1px solid transparent;
    font-size: var(--step-2);
    color: var(--muted);
    text-decoration: none;
    transition: color 220ms var(--ease), border-color 220ms var(--ease);
  }

  .page-about .index-list a:hover,
  .page-about .index-list a:focus-visible {
    color: var(--c-mist);
    border-left-color: var(--c-verify);
  }

  .page-about .ix-num {
    font-family: var(--font-mono);
    font-size: var(--step-1);
    color: var(--c-coral);
  }

  .page-about .index-cta {
    display: inline-block;
  }

  .page-about .timeline-wrap {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .tl-photo {
    margin-top: 6px;
  }

  .page-about .chapter-lede,
  .page-about .about-hero .lede {
    max-width: 40ch;
  }

  .page-about .about-outro {
    padding-inline: clamp(28px, 3.5vw, 48px);
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about .tl-more,
  .page-about .outro-links a,
  .page-about .scene-link,
  .page-about .index-list a {
    transition: none;
  }

  .page-about .tl-item:hover .tl-more,
  .page-about .tl-item:focus-within .tl-more,
  .page-about .tl-item:focus .tl-more {
    max-height: none;
  }
}
<<<END>>>