.page-about {
  --about-rail-w: 168px;
  --about-text: rgba(232, 237, 244, 0.84);
  --about-line: rgba(232, 237, 244, 0.12);
  --about-panel: rgba(16, 31, 51, 0.86);

  position: relative;
  background: var(--ink-900);
  color: var(--white);
  padding-bottom: clamp(64px, 8vw, 112px);
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  padding: calc(var(--header-h) + clamp(28px, 5vw, 64px)) 0 clamp(36px, 5vw, 56px);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: -32% -22% auto -22%;
  height: 132%;
  z-index: 0;
  pointer-events: none;
  background:
    radial-gradient(52% 48% at 18% 22%, rgba(43, 231, 210, 0.16), transparent 68%),
    radial-gradient(44% 46% at 84% 10%, rgba(255, 122, 47, 0.14), transparent 70%),
    radial-gradient(58% 58% at 62% 94%, rgba(59, 91, 255, 0.16), transparent 72%);
}

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

.page-about .about-hero__crumb {
  margin-bottom: clamp(22px, 3.5vw, 36px);
}

.page-about .about-hero__title {
  margin: 0;
  max-width: 15em;
  font-size: clamp(2.05rem, 6.2vw, 4.35rem);
  line-height: 1.07;
  letter-spacing: -0.025em;
  font-weight: 800;
  color: var(--white);
}

.page-about .about-hero__title-accent {
  background-image: linear-gradient(transparent 64%, rgba(43, 231, 210, 0.3) 64%);
  background-repeat: no-repeat;
  background-size: 100% 100%;
  padding-bottom: 0.06em;
}

.page-about .about-hero__body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(28px, 4vw, 48px);
  margin-top: clamp(26px, 4vw, 44px);
}

.page-about .about-hero__lede {
  margin: 0;
  max-width: 36em;
  font-size: clamp(1.0625rem, 0.5vw + 0.95rem, 1.3125rem);
  line-height: 1.8;
  color: var(--about-text);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(22px, 3vw, 30px);
}

.page-about .about-facts {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 20px 18px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-fact {
  min-width: 0;
  padding-left: 14px;
  border-left: 3px solid var(--cyan);
}

.page-about .about-fact--amber { border-left-color: var(--amber); }
.page-about .about-fact--orange { border-left-color: var(--orange); }
.page-about .about-fact--indigo { border-left-color: var(--indigo); }

.page-about .about-fact__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(1.5rem, 1.2vw + 1.15rem, 2.25rem);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.02em;
  color: var(--white);
}

.page-about .about-fact__label {
  display: block;
  margin-top: 9px;
  font-size: 0.8125rem;
  line-height: 1.6;
  color: var(--mist);
}

.page-about .about-hero__rail {
  height: 2px;
  margin-top: clamp(34px, 5vw, 54px);
  border-radius: 2px;
  opacity: 0.8;
  background: linear-gradient(90deg, var(--cyan), var(--indigo) 44%, var(--orange) 100%);
}

.page-about .about-cover {
  margin: clamp(30px, 4vw, 46px) 0 0;
}

.page-about .about-cover img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  border-radius: var(--radius-lg);
  border: 1px solid var(--about-line);
}

.page-about .about-cover__cap {
  margin-top: 14px;
  padding-left: 14px;
  border-left: 3px solid var(--cyan);
  font-size: 0.8125rem;
  line-height: 1.65;
  color: var(--mist);
}

/* ---------- 主布局 ---------- */

.page-about .about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(28px, 4vw, 46px);
  margin-top: clamp(52px, 7vw, 96px);
}

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

.page-about .about-rail__inner {
  padding-top: 14px;
  border-top: 1px solid var(--about-line);
}

.page-about .about-rail__label {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.22em;
  color: var(--mist);
}

.page-about .about-rail__list {
  display: flex;
  flex-wrap: nowrap;
  gap: 8px;
  margin: 0;
  padding: 0 0 6px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: none;
}

.page-about .about-rail__list::-webkit-scrollbar {
  display: none;
}

.page-about .about-rail__link {
  display: block;
  white-space: nowrap;
  padding: 8px 14px;
  border-radius: 999px;
  border: 1px solid var(--about-line);
  font-size: 0.8125rem;
  color: var(--mist);
  text-decoration: none;
  transition: color 0.22s var(--ease), border-color 0.22s var(--ease), background-color 0.22s var(--ease);
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  color: var(--ink-900);
  background: var(--cyan);
  border-color: var(--cyan);
}

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

/* ---------- 章节骨架 ---------- */

.page-about .about-chapter {
  scroll-margin-top: calc(var(--header-h-scrolled) + 32px);
  padding-top: clamp(46px, 6.5vw, 88px);
}

.page-about .about-flow > .about-chapter:first-child {
  padding-top: 0;
}

.page-about .about-chapter__kicker {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.2em;
  color: var(--cyan);
}

.page-about .about-chapter__kicker::before {
  content: "";
  width: 26px;
  height: 2px;
  background: var(--cyan);
}

.page-about .about-chapter__title {
  margin: 14px 0 0;
  max-width: 22em;
  font-size: clamp(1.5rem, 2.8vw, 2.4rem);
  line-height: 1.28;
  letter-spacing: -0.015em;
  font-weight: 800;
  color: var(--white);
}

.page-about .about-prose {
  max-width: 68ch;
  margin-top: clamp(20px, 3vw, 30px);
  font-size: clamp(1rem, 0.4vw + 0.9rem, 1.125rem);
  line-height: 1.85;
  color: var(--about-text);
}

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

.page-about .about-prose p + p {
  margin-top: 1.15em;
}

.page-about .about-prose a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(43, 231, 210, 0.42);
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
}

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

.page-about .about-chapter .aside-note {
  max-width: 60ch;
  margin: clamp(24px, 3vw, 34px) 0 0;
  padding-left: 16px;
  border-left: 3px solid var(--cyan);
  font-size: 0.875rem;
  line-height: 1.78;
  color: var(--mist);
}

.page-about .about-pull {
  margin: clamp(24px, 3.4vw, 36px) 0 0;
  max-width: 26em;
  padding: clamp(18px, 2.4vw, 26px) clamp(20px, 2.8vw, 30px);
  border-left: 4px solid var(--amber);
  border-radius: var(--radius-md);
  background: linear-gradient(105deg, rgba(255, 194, 77, 0.18), rgba(255, 194, 77, 0.03) 74%);
  font-size: clamp(1.0625rem, 1.1vw + 0.85rem, 1.375rem);
  font-weight: 700;
  line-height: 1.55;
  color: var(--white);
}

/* ---------- 阶段卡片 ---------- */

.page-about .about-phases {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
  margin-top: clamp(28px, 4vw, 42px);
}

.page-about .about-phase {
  position: relative;
  overflow: hidden;
  padding: clamp(20px, 2.6vw, 28px);
  border-radius: var(--radius-md);
  border: 1px solid var(--about-line);
  background: var(--ink-800);
}

.page-about .about-phase::after {
  content: "";
  position: absolute;
  inset: auto 0 0 0;
  height: 2px;
  opacity: 0.55;
  background: linear-gradient(90deg, var(--cyan), transparent 78%);
}

.page-about .about-phase__year {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(1.375rem, 1.6vw + 1rem, 2rem);
  font-weight: 700;
  line-height: 1.05;
  letter-spacing: -0.02em;
  color: var(--amber);
}

.page-about .about-phase__title {
  margin: 14px 0 0;
  font-size: 1.0625rem;
  font-weight: 700;
  line-height: 1.5;
  color: var(--white);
}

.page-about .about-phase__text {
  margin: 10px 0 0;
  font-size: 0.9375rem;
  line-height: 1.76;
  color: var(--about-text);
}

/* ---------- 光轨图 ---------- */

.page-about .about-track {
  margin: clamp(32px, 4.6vw, 52px) 0 0;
}

.page-about .about-track img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 2 / 1;
  object-fit: cover;
  border-radius: var(--radius-md);
}

.page-about .about-track__cap {
  margin-top: 12px;
  font-size: 0.8125rem;
  line-height: 1.65;
  color: var(--mist);
}

/* ---------- 团队 ---------- */

.page-about .about-crew {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 14px;
  margin: clamp(24px, 3vw, 34px) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-crew__item {
  padding: 16px 18px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--about-line);
  background: var(--about-panel);
}

.page-about .about-crew__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 1.5rem;
  font-weight: 700;
  line-height: 1;
  color: var(--cyan);
}

.page-about .about-crew__label {
  display: block;
  margin-top: 9px;
  font-size: 0.8125rem;
  line-height: 1.55;
  color: var(--mist);
}

.page-about .about-teamshot {
  margin: clamp(26px, 3.6vw, 38px) 0 0;
}

.page-about .about-teamshot img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 14 / 9;
  object-fit: cover;
  border-radius: var(--radius-md);
  border: 1px solid var(--about-line);
}

/* ---------- 时间线 ---------- */

.page-about .about-timeline {
  position: relative;
  margin: clamp(24px, 3.4vw, 38px) 0 0;
  padding: 0 0 0 26px;
  list-style: none;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 12px;
  bottom: 12px;
  width: 2px;
  background: linear-gradient(180deg, var(--amber), rgba(43, 231, 210, 0.4) 58%, transparent);
}

.page-about .about-node {
  position: relative;
}

.page-about .about-node + .about-node {
  margin-top: 8px;
}

.page-about .about-node::before {
  content: "";
  position: absolute;
  left: -26px;
  top: 21px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--ink-900);
  border: 2px solid var(--amber);
}

.page-about .about-node__summary {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 12px;
  padding: 14px 16px;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  cursor: pointer;
  list-style: none;
  transition: background-color 0.22s var(--ease), border-color 0.22s var(--ease);
}

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

.page-about .about-node__summary::marker {
  content: "";
}

.page-about .about-node__summary:hover,
.page-about .about-node__summary:focus-visible {
  background: var(--about-panel);
  border-color: var(--about-line);
}

.page-about .about-node[open] .about-node__summary {
  background: var(--about-panel);
  border-color: rgba(255, 194, 77, 0.4);
}

.page-about .about-node__year {
  font-family: var(--font-mono);
  font-size: 1.0625rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--amber);
}

.page-about .about-node__name {
  font-size: 1rem;
  font-weight: 700;
  color: var(--white);
}

.page-about .about-node__toggle {
  margin-left: auto;
  width: 20px;
  text-align: center;
  font-family: var(--font-mono);
  font-size: 1.125rem;
  line-height: 1;
  color: var(--cyan);
}

.page-about .about-node__toggle::after {
  content: "+";
}

.page-about .about-node[open] .about-node__toggle::after {
  content: "–";
}

.page-about .about-node__desc {
  max-width: 62ch;
  margin: 0;
  padding: 2px 16px 18px;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--about-text);
}

/* ---------- 结尾入口 ---------- */

.page-about .about-next {
  margin-top: clamp(48px, 6.5vw, 84px);
  padding: clamp(26px, 3.4vw, 40px);
  border-radius: var(--radius-lg);
  border: 1px solid var(--about-line);
  background:
    radial-gradient(70% 120% at 92% 0%, rgba(43, 231, 210, 0.12), transparent 62%),
    var(--ink-800);
}

.page-about .about-next__title {
  margin: 0;
  font-size: clamp(1.375rem, 2.4vw, 1.875rem);
  line-height: 1.3;
  letter-spacing: -0.015em;
  font-weight: 800;
  color: var(--white);
}

.page-about .about-next__text {
  margin: 12px 0 0;
  max-width: 42em;
  font-size: 0.9375rem;
  line-height: 1.78;
  color: var(--about-text);
}

.page-about .about-next__list {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
  margin: clamp(22px, 3vw, 30px) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-next__link {
  display: flex;
  flex-direction: column;
  gap: 5px;
  padding: 16px 18px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--about-line);
  background: rgba(10, 22, 38, 0.55);
  color: var(--white);
  font-size: 1rem;
  font-weight: 700;
  text-decoration: none;
  transition: border-color 0.22s var(--ease), transform 0.22s var(--ease), background-color 0.22s var(--ease);
}

.page-about .about-next__link span {
  font-size: 0.8125rem;
  font-weight: 400;
  line-height: 1.6;
  color: var(--mist);
}

.page-about .about-next__link:hover,
.page-about .about-next__link:focus-visible {
  border-color: var(--cyan);
  background: rgba(43, 231, 210, 0.08);
  transform: translateY(-2px);
}

/* ---------- 响应式 ---------- */

@media (min-width: 480px) {
  .page-about .about-facts {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

@media (min-width: 700px) {
  .page-about .about-phases {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 20px;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__body {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr);
    column-gap: clamp(40px, 5vw, 72px);
    align-items: start;
  }
}

@media (min-width: 1024px) {
  .page-about .about-layout {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    column-gap: clamp(40px, 5vw, 84px);
  }

  .page-about .about-rail__inner {
    position: sticky;
    top: calc(var(--header-h-scrolled) + 32px);
  }

  .page-about .about-rail__list {
    flex-direction: column;
    gap: 2px;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .about-rail__link {
    border-radius: 0;
    border: 0;
    border-left: 2px solid var(--about-line);
    padding: 9px 0 9px 14px;
    font-size: 0.875rem;
  }

  .page-about .about-rail__link:hover,
  .page-about .about-rail__link:focus-visible {
    background: transparent;
    color: var(--white);
    border-left-color: var(--cyan);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-next__link,
  .page-about .about-rail__link,
  .page-about .about-node__summary {
    transition: none;
  }

  .page-about .about-next__link:hover,
  .page-about .about-next__link:focus-visible {
    transform: none;
  }
}
<<<END>>>