.page-about {
  --about-rail: 250px;
  --about-line: 1px solid var(--tick);
  font-family: var(--font-body);
  color: var(--charcoal);
  background: var(--sand);
  overflow-x: hidden;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: clamp(20px, 4vw, 44px) 0 clamp(34px, 6vw, 76px);
  background: linear-gradient(180deg, var(--sand-2) 0%, var(--sand) 58%, var(--sand) 100%);
  border-bottom: 2px solid var(--ink);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: clamp(8px, 1.6vw, 18px);
  border: 1px solid var(--tick);
  pointer-events: none;
  z-index: 0;
}

.page-about .about-hero__inner {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(22px, 4vw, 40px);
}

.page-about .about-hero__crumb {
  font-size: 0.84rem;
  color: var(--clay);
}

.page-about .about-hero__crumb a {
  color: var(--ink);
  text-decoration: none;
  border-bottom: 1px solid var(--tick);
}

.page-about .about-hero__crumb a:hover,
.page-about .about-hero__crumb a:focus-visible {
  border-bottom-color: var(--orange-deep);
}

.page-about .about-hero__title {
  font-family: var(--font-display);
  font-weight: 900;
  letter-spacing: -0.03em;
  font-size: clamp(2rem, 6.6vw, 4.2rem);
  line-height: 1.08;
  color: var(--ink);
  margin: 14px 0 0;
  max-width: 22ch;
}

.page-about .about-hero__intro {
  margin: 18px 0 0;
  font-size: clamp(0.98rem, 2.2vw, 1.08rem);
  line-height: 1.85;
  color: var(--clay);
  max-width: 46ch;
}

.page-about .about-hero__facts {
  list-style: none;
  margin: clamp(22px, 4vw, 32px) 0 0;
  padding: clamp(14px, 2.4vw, 20px) 0 0;
  border-top: var(--about-line);
  display: flex;
  flex-wrap: wrap;
  gap: 14px clamp(20px, 4vw, 44px);
}

.page-about .about-hero__facts li {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.page-about .about-hero__facts b {
  font-family: var(--font-mono);
  font-weight: 800;
  font-size: clamp(1.35rem, 3vw, 1.85rem);
  line-height: 1.1;
  color: var(--ink);
  font-variant-numeric: tabular-nums;
}

.page-about .about-hero__facts span {
  font-size: 0.78rem;
  letter-spacing: 0.04em;
  color: var(--clay);
}

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

.page-about .about-hero__figure .media-note {
  margin-top: 10px;
  font-size: 0.76rem;
  color: var(--clay);
  letter-spacing: 0.02em;
}

/* ---------- 主体两栏 ---------- */
.page-about .about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
}

.page-about .about-rail {
  padding: clamp(20px, 4vw, 30px) 0;
  border-bottom: var(--about-line);
}

.page-about .about-rail__title {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.18em;
  color: var(--orange-deep);
}

.page-about .about-rail__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 4px 14px;
}

.page-about .about-rail__link {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 7px 0;
  font-size: 0.88rem;
  line-height: 1.4;
  color: var(--clay);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  color: var(--ink);
  border-bottom-color: var(--orange);
}

.page-about .about-rail__idx {
  font-family: var(--font-mono);
  font-weight: 800;
  font-size: 0.72rem;
  color: var(--orange-deep);
  font-variant-numeric: tabular-nums;
}

/* ---------- 章节 ---------- */
.page-about .chapter {
  position: relative;
  padding: clamp(34px, 6vw, 72px) 0;
  border-top: var(--about-line);
  scroll-margin-top: 100px;
}

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

.page-about .chapter__head {
  display: grid;
  gap: 4px;
}

.page-about .chapter__num {
  font-family: var(--font-mono);
  font-weight: 800;
  font-size: clamp(2.2rem, 7vw, 4.2rem);
  line-height: 0.9;
  letter-spacing: -0.02em;
  color: var(--orange);
  opacity: 0.24;
  font-variant-numeric: tabular-nums;
}

.page-about .chapter__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  letter-spacing: -0.02em;
  font-size: clamp(1.45rem, 3.6vw, 2.25rem);
  line-height: 1.22;
  color: var(--ink);
}

.page-about .chapter__body {
  margin-top: clamp(16px, 2.6vw, 26px);
}

.page-about .about-text {
  max-width: 64ch;
  margin: 0 0 14px;
  font-size: 1rem;
  line-height: 1.85;
  color: var(--charcoal);
}

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

.page-about .about-text--closing {
  margin-top: 22px;
  padding-left: 18px;
  border-left: 2px solid var(--sand-3);
  color: var(--clay);
}

/* ---------- 编辑约定 ---------- */
.page-about .axioms {
  margin-top: clamp(20px, 3vw, 30px);
  padding: clamp(16px, 3vw, 26px);
  background: var(--sand-2);
  border-left: 3px solid var(--orange);
}

.page-about .axioms__title {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.18em;
  color: var(--orange-deep);
}

.page-about .axioms__list {
  list-style: none;
  counter-reset: ax;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .axioms__list li {
  counter-increment: ax;
  display: grid;
  grid-template-columns: 2.1rem minmax(0, 1fr);
  gap: 6px;
  font-size: 0.95rem;
  line-height: 1.75;
  color: var(--ink);
}

.page-about .axioms__list li::before {
  content: counter(ax, decimal-leading-zero);
  font-family: var(--font-mono);
  font-weight: 800;
  font-size: 0.74rem;
  color: var(--orange-deep);
  padding-top: 0.42em;
}

/* ---------- 时间线 ---------- */
.page-about .timeline {
  margin-top: clamp(18px, 3vw, 28px);
  border-top: 2px solid var(--ink);
}

.page-about .tl-node {
  border-bottom: var(--about-line);
}

.page-about .tl-node summary {
  display: grid;
  grid-template-columns: 4.2rem minmax(0, 1fr) 1.2rem;
  align-items: center;
  gap: 10px;
  padding: 13px 0;
  cursor: pointer;
  list-style: none;
}

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

.page-about .tl-node summary:focus-visible {
  outline: 2px solid var(--orange-deep);
  outline-offset: 3px;
}

.page-about .tl-year {
  font-family: var(--font-mono);
  font-weight: 800;
  font-size: clamp(1.1rem, 3vw, 1.45rem);
  color: var(--orange-deep);
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.02em;
}

.page-about .tl-label {
  font-size: 0.98rem;
  font-weight: 700;
  line-height: 1.5;
  color: var(--ink);
}

.page-about .tl-node summary::after {
  content: "+";
  justify-self: end;
  font-family: var(--font-mono);
  font-weight: 800;
  font-size: 1.05rem;
  color: var(--orange-deep);
}

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

.page-about .tl-node__body {
  margin: 0 0 16px;
  padding-left: calc(4.2rem + 10px);
  max-width: 62ch;
  font-size: 0.94rem;
  line-height: 1.8;
  color: var(--clay);
}

.page-about .timeline-figure {
  margin: clamp(24px, 4vw, 38px) 0 0;
}

.page-about .timeline-figure .media-note {
  margin-top: 10px;
  font-size: 0.76rem;
  color: var(--clay);
}

/* ---------- 团队 ---------- */
.page-about .crew {
  margin-top: clamp(18px, 3vw, 26px);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--tick);
  border: 1px solid var(--tick);
}

.page-about .crew__cell {
  background: var(--white);
  padding: clamp(16px, 2.6vw, 24px);
  transition: background var(--dur) var(--ease);
}

.page-about .crew__cell:hover,
.page-about .crew__cell:focus-within {
  background: var(--sand-2);
}

.page-about .crew__cell::before {
  content: "";
  display: block;
  width: 28px;
  height: 3px;
  margin-bottom: 12px;
  background: var(--orange);
}

.page-about .crew__k {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 1.02rem;
  letter-spacing: -0.01em;
  color: var(--ink);
}

.page-about .crew__d {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.75;
  color: var(--clay);
}

.page-about .crew-stats {
  margin-top: 18px;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--field);
  border: 1px solid var(--field);
}

.page-about .crew-stats__cell {
  background: var(--field);
  color: var(--sand);
  padding: 16px clamp(14px, 2.4vw, 20px);
  display: flex;
  align-items: baseline;
  gap: 10px;
}

.page-about .crew-stats__num {
  font-family: var(--font-mono);
  font-weight: 800;
  font-size: clamp(1.5rem, 3.6vw, 2rem);
  line-height: 1;
  color: var(--amber);
  font-variant-numeric: tabular-nums;
}

.page-about .crew-stats__label {
  font-size: 0.82rem;
  line-height: 1.5;
  color: var(--sand);
  opacity: 0.9;
}

/* ---------- 信息标记 ---------- */
.page-about .signals {
  list-style: none;
  margin: clamp(18px, 3vw, 26px) 0 0;
  padding: 0;
  display: grid;
  gap: 0;
  border-top: var(--about-line);
}

.page-about .signals__item {
  display: grid;
  grid-template-columns: 14px minmax(0, 1fr);
  gap: 14px;
  padding: 18px 0;
  border-bottom: var(--about-line);
}

.page-about .signals__swatch {
  display: block;
  width: 14px;
  height: 100%;
  min-height: 34px;
  border-radius: var(--radius);
}

.page-about .signals__swatch--tick {
  background: var(--sand-3);
  border: 1px solid var(--tick);
}

.page-about .signals__swatch--field {
  background: var(--field);
}

.page-about .signals__swatch--red {
  background: var(--track-red);
}

.page-about .signals__swatch--sand {
  background: var(--orange);
}

.page-about .signals__title {
  margin: 0 0 4px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 1rem;
  color: var(--ink);
}

.page-about .signals__text {
  margin: 0;
  font-size: 0.92rem;
  line-height: 1.78;
  color: var(--clay);
  max-width: 58ch;
}

/* ---------- 场馆 ---------- */
.page-about .venue-band {
  margin-top: clamp(18px, 3vw, 26px);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--ink);
  border: 1px solid var(--ink);
}

.page-about .venue-band__cell {
  background: var(--ink);
  padding: 18px clamp(14px, 2.4vw, 22px);
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.page-about .venue-band__num {
  font-family: var(--font-mono);
  font-weight: 800;
  font-size: clamp(1.55rem, 4vw, 2.15rem);
  line-height: 1;
  color: var(--amber);
  font-variant-numeric: tabular-nums;
}

.page-about .venue-band__num em {
  font-style: normal;
  font-size: 0.7em;
  color: var(--orange);
  margin-left: 2px;
}

.page-about .venue-band__label {
  font-size: 0.78rem;
  letter-spacing: 0.04em;
  color: var(--sand-2);
}

.page-about .venue-cols {
  margin-top: clamp(18px, 3vw, 28px);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(18px, 3vw, 32px);
  align-items: start;
}

.page-about .venue-cols__fig {
  margin: 0;
}

.page-about .venue-cols__fig .media-note {
  margin-top: 10px;
  font-size: 0.76rem;
  color: var(--clay);
}

/* ---------- 入口 ---------- */
.page-about .exits {
  list-style: none;
  margin: clamp(18px, 3vw, 26px) 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--tick);
  border: 1px solid var(--tick);
}

.page-about .exits__link {
  display: grid;
  grid-template-columns: 2rem minmax(0, 1fr) 1.2rem;
  grid-template-areas:
    "k t arrow"
    "k d arrow";
  align-items: center;
  column-gap: 12px;
  row-gap: 2px;
  padding: 15px clamp(14px, 2.4vw, 20px);
  background: var(--sand);
  text-decoration: none;
  transition: background var(--dur) var(--ease);
}

.page-about .exits__link:hover,
.page-about .exits__link:focus-visible {
  background: var(--sand-2);
}

.page-about .exits__k {
  grid-area: k;
  font-family: var(--font-mono);
  font-weight: 800;
  font-size: 0.78rem;
  color: var(--orange-deep);
  font-variant-numeric: tabular-nums;
}

.page-about .exits__t {
  grid-area: t;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 1rem;
  color: var(--ink);
}

.page-about .exits__d {
  grid-area: d;
  font-size: 0.85rem;
  line-height: 1.6;
  color: var(--clay);
}

.page-about .exits__arrow {
  grid-area: arrow;
  justify-self: end;
  font-family: var(--font-mono);
  font-weight: 800;
  color: var(--orange-deep);
  transition: transform var(--dur) var(--ease);
}

.page-about .exits__link:hover .exits__arrow,
.page-about .exits__link:focus-visible .exits__arrow {
  transform: translateX(3px);
}

/* ---------- 断点 ---------- */
@media (min-width: 640px) {
  .page-about .crew {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

  .page-about .crew-stats__cell {
    flex-direction: column;
    align-items: flex-start;
    gap: 6px;
  }

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

  .page-about .signals__item {
    grid-template-columns: 14px minmax(0, 1fr);
    gap: 20px;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__inner {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    column-gap: clamp(28px, 5vw, 72px);
    align-items: end;
  }

  .page-about .about-hero__crumb {
    grid-column: 1 / -1;
  }

  .page-about .about-hero__lead {
    align-self: end;
  }

  .page-about .about-hero__figure {
    align-self: end;
  }

  .page-about .venue-cols {
    grid-template-columns: minmax(0, 6fr) minmax(0, 5fr);
  }

  .page-about .venue-cols__fig {
    margin-top: 4px;
  }
}

@media (min-width: 1024px) {
  .page-about .about-body {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    column-gap: clamp(36px, 5vw, 88px);
  }

  .page-about .about-rail {
    position: sticky;
    top: 104px;
    align-self: start;
    padding: clamp(48px, 6vw, 80px) 0 0;
    border-bottom: 0;
    border-right: var(--about-line);
    padding-right: 20px;
  }

  .page-about .about-rail__list {
    grid-template-columns: minmax(0, 1fr);
    gap: 0;
  }

  .page-about .about-rail__link {
    border-bottom: 1px solid transparent;
    padding: 9px 0;
  }

  .page-about .chapter__head {
    gap: 8px;
  }
}

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

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