.page-about {
  --about-gap: clamp(20px, 4vw, 44px);
  --about-pad: clamp(48px, 8vw, 100px);
  position: relative;
  overflow-x: hidden;
}

.page-about .about-crumbs {
  padding-top: clamp(16px, 3vw, 28px);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: clamp(28px, 5vw, 60px) 0 clamp(40px, 7vw, 84px);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: -20% -30% auto -30%;
  height: 90%;
  background: radial-gradient(60% 55% at 62% 35%, rgba(108, 75, 232, 0.20), transparent 70%),
    radial-gradient(45% 40% at 22% 10%, rgba(232, 107, 176, 0.12), transparent 70%);
  pointer-events: none;
}

.page-about .about-hero__grid {
  position: relative;
  display: grid;
  gap: clamp(28px, 5vw, 52px);
  align-items: center;
}

.page-about .about-hero__title {
  margin: 14px 0 22px;
  font-family: var(--font-serif);
  font-weight: 800;
  font-size: clamp(40px, 8.4vw, 92px);
  line-height: 1.02;
  letter-spacing: -0.02em;
  color: var(--stardust);
}

.page-about .about-hero__lead {
  max-width: 36ch;
  color: var(--stardust);
  opacity: 0.86;
  font-size: clamp(15.5px, 2.4vw, 17.5px);
  line-height: 1.95;
}

.page-about .about-hero__facts {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 26px;
  margin: 26px 0 0;
  padding: 18px 0 0;
  list-style: none;
  border-top: 1px solid var(--line);
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--stardust);
}

.page-about .about-hero__facts span {
  display: block;
  margin-bottom: 4px;
  color: var(--mist);
  font-size: 11px;
  letter-spacing: 0.16em;
}

.page-about .about-hero__actions {
  margin-top: 28px;
}

.page-about .about-hero__visual {
  position: relative;
  order: -1;
  max-width: 420px;
  margin: 0 auto;
  width: 100%;
}

.page-about .about-sky {
  display: block;
  width: 100%;
  height: auto;
}

/* ---------- 章节框架 ---------- */
.page-about .about-chapter {
  padding: var(--about-pad) 0;
}

.page-about .about-chapter--tint {
  background: linear-gradient(180deg, rgba(12, 18, 38, 0.82), rgba(5, 7, 14, 0));
}

.page-about .about-grid {
  display: grid;
  gap: clamp(22px, 4vw, 40px);
}

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

.page-about .about-rail__num {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.14em;
  color: var(--gold);
}

.page-about .about-rail__line {
  width: 34px;
  height: 1px;
  background: linear-gradient(90deg, var(--galaxy), rgba(42, 48, 80, 0));
}

.page-about .about-rail__note {
  margin: 0;
}

.page-about .vertical-note {
  font-size: 12px;
  letter-spacing: 0.4em;
  color: var(--mist);
  transition: color 520ms var(--ease);
}

.page-about .vertical-note.is-visible {
  color: var(--stardust);
}

.page-about .about-h2 {
  margin: 0 0 22px;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: clamp(26px, 4.6vw, 44px);
  line-height: 1.22;
  letter-spacing: -0.01em;
  color: var(--stardust);
}

.page-about .about-body p {
  max-width: 40ch;
  margin: 0 0 18px;
  color: var(--mist);
  font-size: clamp(15px, 2.2vw, 17px);
  line-height: 1.95;
}

.page-about .about-body p:first-of-type {
  color: var(--stardust);
  opacity: 0.92;
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: 0;
  border: 1px solid var(--line);
  background: linear-gradient(150deg, rgba(23, 26, 58, 0.85), rgba(5, 7, 14, 0.6));
  overflow: hidden;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  filter: saturate(0.92);
}

.page-about .about-figure .figure__caption {
  padding: 12px 16px 14px;
  border-top: 1px solid var(--line);
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--mist);
}

.page-about .about-figure--inline {
  margin: 30px 0 0;
}

/* ---------- 四层剖面 ---------- */
.page-about .floors {
  list-style: none;
  margin: 30px 0 26px;
  padding: 0;
  display: grid;
  gap: 10px;
  transform: skewY(-2deg);
}

.page-about .floors__item {
  transform: skewY(2deg);
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr);
  gap: 4px 14px;
  padding: 16px 18px;
  background: linear-gradient(100deg, rgba(23, 26, 58, 0.92), rgba(12, 18, 38, 0.62));
  border-left: 2px solid var(--line);
}

.page-about .floors__item:nth-child(1) { border-left-color: var(--gold); }
.page-about .floors__item:nth-child(2) { border-left-color: var(--nebula); }
.page-about .floors__item:nth-child(3) { border-left-color: var(--galaxy); }
.page-about .floors__item:nth-child(4) { border-left-color: var(--ice); }

.page-about .floors__idx {
  grid-column: 1;
  grid-row: 1;
  align-self: center;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--gold);
}

.page-about .floors__name {
  grid-column: 2;
  font-family: var(--font-serif);
  font-size: clamp(17px, 2.6vw, 20px);
  color: var(--stardust);
}

.page-about .floors__desc {
  grid-column: 2;
  margin-top: 4px;
  font-size: 14px;
  line-height: 1.8;
  color: var(--mist);
}

/* ---------- 时间轴 ---------- */
.page-about .timeline {
  list-style: none;
  margin: 30px 0 0;
  padding: 0;
}

.page-about .timeline__item {
  position: relative;
  padding-left: 20px;
  border-left: 1px solid var(--line);
}

.page-about .timeline__item::before {
  content: "";
  position: absolute;
  left: -4px;
  top: 30px;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--galaxy);
  box-shadow: 0 0 0 3px rgba(108, 75, 232, 0.18);
}

.page-about .timeline__node summary {
  display: grid;
  grid-template-columns: 72px minmax(0, 1fr);
  gap: 12px;
  align-items: baseline;
  padding: 16px 0;
  cursor: pointer;
  list-style: none;
}

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

.page-about .timeline__node summary:hover .timeline__brief,
.page-about .timeline__node summary:focus-visible .timeline__brief {
  color: var(--ice);
}

.page-about .timeline__year {
  font-family: var(--font-mono);
  font-size: 13.5px;
  letter-spacing: 0.08em;
  color: var(--gold);
}

.page-about .timeline__brief {
  font-size: clamp(15.5px, 2.3vw, 17.5px);
  line-height: 1.6;
  color: var(--stardust);
  transition: color 320ms var(--ease);
}

.page-about .timeline__node[open] .timeline__brief {
  color: var(--ice);
}

.page-about .timeline__body {
  padding: 0 0 20px;
  border-top: 1px dashed rgba(42, 48, 80, 0.8);
  margin-top: 2px;
  padding-top: 14px;
}

.page-about .timeline__body p {
  max-width: 42ch;
  margin: 0;
  font-size: 15px;
  line-height: 1.9;
  color: var(--mist);
}

/* ---------- 会员轨道 ---------- */
.page-about .tiers {
  display: grid;
  gap: 20px;
  margin: 8px 0 26px;
}

.page-about .orbits {
  display: block;
  width: 100%;
  max-width: 340px;
  height: auto;
}

.page-about .orbits__a { stroke: var(--gold); stroke-width: 3; }
.page-about .orbits__b { stroke: var(--nebula); stroke-width: 2; }
.page-about .orbits__c { stroke: var(--galaxy); stroke-width: 1.2; }

.page-about .tiers__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .tiers__item {
  display: grid;
  gap: 6px;
  padding: 14px 18px;
  border: 1px solid var(--line);
  background: linear-gradient(120deg, rgba(23, 26, 58, 0.7), rgba(5, 7, 14, 0.35));
  transition: border-color 320ms var(--ease);
}

.page-about .tiers__item:hover {
  border-color: rgba(95, 227, 214, 0.55);
}

.page-about .tiers__name {
  font-family: var(--font-serif);
  font-size: 19px;
  color: var(--stardust);
  padding-left: 12px;
  position: relative;
}

.page-about .tiers__name::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 6px;
  height: 1px;
}

.page-about .tiers__item--c .tiers__name::before { background: var(--galaxy); width: 6px; height: 1px; }
.page-about .tiers__item--b .tiers__name::before { background: var(--nebula); width: 9px; height: 2px; }
.page-about .tiers__item--a .tiers__name::before { background: var(--gold); width: 12px; height: 3px; }

.page-about .tiers__desc {
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--mist);
}

/* ---------- 链接组 ---------- */
.page-about .about-links {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  display: grid;
  gap: 0;
}

.page-about .about-links li {
  border-top: 1px solid var(--line);
}

.page-about .about-links li:last-child {
  border-bottom: 1px solid var(--line);
}

.page-about .about-links a {
  display: block;
  padding: 15px 0;
  color: var(--ice);
  text-decoration: none;
  font-size: 15.5px;
  letter-spacing: 0.02em;
  transition: color 300ms var(--ease), padding-left 300ms var(--ease);
}

.page-about .about-links a::after {
  content: " →";
  font-family: var(--font-mono);
  font-size: 12px;
}

.page-about .about-links a:hover,
.page-about .about-links a:focus-visible {
  color: var(--gold);
  padding-left: 6px;
}

/* ---------- 收尾 ---------- */
.page-about .about-cta {
  padding: clamp(40px, 7vw, 88px) 0 clamp(56px, 8vw, 96px);
}

.page-about .about-cta__inner {
  padding: clamp(26px, 4.5vw, 52px);
  background: linear-gradient(140deg, rgba(122, 31, 61, 0.42), rgba(23, 26, 58, 0.85) 62%);
}

.page-about .about-cta__title {
  margin: 12px 0 14px;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: clamp(24px, 4.2vw, 38px);
  line-height: 1.25;
  color: var(--stardust);
}

.page-about .about-cta__text {
  max-width: 44ch;
  margin: 0 0 24px;
  font-size: 15.5px;
  line-height: 1.9;
  color: var(--mist);
}

/* ---------- 断点 ---------- */
@media (min-width: 720px) {
  .page-about .about-hero__facts {
    gap: 12px 34px;
  }

  .page-about .tiers {
    grid-template-columns: minmax(0, 0.72fr) minmax(0, 1fr);
    align-items: center;
    gap: 28px;
  }
}

@media (min-width: 960px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.82fr);
    gap: clamp(32px, 5vw, 64px);
  }

  .page-about .about-hero__visual {
    order: 0;
    max-width: none;
  }

  .page-about .about-grid {
    grid-template-columns: 84px minmax(0, 1fr);
    gap: clamp(28px, 4vw, 56px);
  }

  .page-about .about-grid--media-right {
    grid-template-columns: 84px minmax(0, 1fr) minmax(0, 0.78fr);
  }

  .page-about .about-grid--media-left {
    grid-template-columns: 84px minmax(0, 0.78fr) minmax(0, 1fr);
  }

  .page-about .about-rail {
    position: sticky;
    top: 104px;
    align-self: start;
    flex-direction: column;
    align-items: flex-start;
    gap: 14px;
    padding-top: 6px;
  }

  .page-about .about-rail__line {
    width: 1px;
    height: 52px;
    background: linear-gradient(180deg, var(--line), rgba(42, 48, 80, 0));
  }

  .page-about .vertical-note {
    writing-mode: vertical-rl;
    text-orientation: upright;
    letter-spacing: 0.36em;
    line-height: 1;
  }

  .page-about .about-figure {
    align-self: start;
    margin-top: 6px;
  }

  .page-about .about-figure--inline {
    margin: 34px 0 0;
  }

  .page-about .floors__item {
    grid-template-columns: 52px 150px minmax(0, 1fr);
    align-items: baseline;
    gap: 4px 22px;
    padding: 18px 24px;
  }

  .page-about .floors__name {
    grid-column: 2;
  }

  .page-about .floors__desc {
    grid-column: 3;
    margin-top: 0;
  }

  .page-about .timeline {
    gap: 16px;
  }

  .page-about .timeline__item {
    padding-left: 0;
    border-left: 0;
    border-top: 1px solid var(--line);
  }

  .page-about .timeline__item::before {
    left: auto;
    right: 0;
    top: -4px;
  }

  .page-about .timeline__item:nth-child(odd) {
    margin-right: 14%;
  }

  .page-about .timeline__item:nth-child(even) {
    margin-left: 14%;
  }

  .page-about .timeline__node summary {
    grid-template-columns: 84px minmax(0, 1fr);
    padding: 20px 0;
  }
}

@media (min-width: 1200px) {
  .page-about .about-hero__lead {
    font-size: 18px;
  }

  .page-about .about-grid--media-right {
    grid-template-columns: 84px minmax(0, 1fr) minmax(0, 0.7fr);
  }
}

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

  .page-about .floors__item {
    transform: none;
  }

  .page-about .about-links a,
  .page-about .timeline__brief,
  .page-about .tiers__item,
  .page-about .vertical-note {
    transition: none;
  }
}
<<<END>>>