.page-about {
  --about-rail-w: 96px;
  --about-stage-pad: 32px;
  color: var(--sand-300);
}

/* ---------- 面包屑 ---------- */
.page-about .crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding: 20px 0 4px;
  font-family: var(--font-index);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--mist);
}

.page-about .crumbs__item {
  color: var(--mist);
  text-decoration: none;
}

.page-about .crumbs__item:hover,
.page-about .crumbs__item:focus-visible {
  color: var(--sand-300);
}

.page-about .crumbs__item--current {
  color: var(--sand-500);
}

.page-about .crumbs__sep {
  color: var(--line-strong);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: 24px 0 56px;
  background:
    linear-gradient(180deg, rgba(23, 39, 74, .55) 0%, rgba(8, 18, 33, 0) 82%);
  border-bottom: 1px solid var(--line);
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, var(--grid) 1px, transparent 1px),
    linear-gradient(to bottom, var(--grid) 1px, transparent 1px);
  background-size: 48px 48px;
  opacity: .9;
  pointer-events: none;
}

.page-about .about-hero__grid {
  position: relative;
  display: grid;
  grid-template-columns: 1fr;
  gap: 40px;
  align-items: end;
}

.page-about .about-hero__kicker {
  margin: 0 0 14px;
  font-family: var(--font-index);
  font-size: 12px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--sand-500);
}

.page-about .about-hero h1 {
  margin: 0 0 20px;
  max-width: 18ch;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 34px;
  line-height: 1.16;
  letter-spacing: -.01em;
  color: var(--paper);
}

.page-about .about-hero__lead {
  margin: 0;
  max-width: 38em;
  font-size: 16px;
  line-height: 1.78;
  color: var(--sand-300);
}

.page-about .about-hero__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 32px 0 0;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-hero__stat {
  padding: 14px 16px 16px;
  background: var(--ink-900);
}

.page-about .about-hero__stat-label {
  margin: 0;
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--mist);
}

.page-about .about-hero__stat-value {
  margin: 6px 0 0;
  font-family: var(--font-index);
  font-variant-numeric: tabular-nums;
  font-size: 32px;
  line-height: 1;
  font-weight: 700;
  color: var(--sand-500);
}

.page-about .about-hero__figure {
  margin: 0;
  padding: 20px 18px 16px;
  background: var(--ink-900);
  border: 1px solid var(--line);
}

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

.page-about .about-chart__axis {
  stroke: var(--line-strong);
  stroke-width: 1;
}

.page-about .about-chart__bar {
  fill: var(--sand-700);
}

.page-about .about-chart__bar--v1 { fill: #6f5824; }
.page-about .about-chart__bar--v2 { fill: var(--sand-700); }
.page-about .about-chart__bar--v3 { fill: var(--sand-500); }
.page-about .about-chart__bar--v4 { fill: var(--sand-300); }

.page-about .about-chart__key {
  font-family: var(--font-index);
  font-size: 13px;
  font-weight: 700;
  fill: var(--sand-300);
}

.page-about .about-chart__val {
  font-family: var(--font-index);
  font-size: 11px;
  fill: var(--mist);
}

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

/* ---------- 通用小节头 ---------- */
.page-about .section {
  padding: var(--block) 0;
}

.page-about .section__head {
  max-width: 46em;
  margin-bottom: 40px;
}

.page-about .section__index {
  margin: 0 0 8px;
  font-family: var(--font-index);
  font-size: 12px;
  letter-spacing: .18em;
  color: var(--sand-700);
}

.page-about .section__title {
  margin: 0 0 14px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 26px;
  line-height: 1.3;
  letter-spacing: -.005em;
  color: var(--paper);
}

.page-about .about-chronicle__intro,
.page-about .about-sources__intro,
.page-about .about-criteria__intro,
.page-about .about-versions__intro,
.page-about .about-team__intro {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--sand-300);
}

/* ---------- 编年长卷 ---------- */
.page-about .about-chronicle {
  border-bottom: 1px solid var(--line);
}

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

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

.page-about .ledger__body {
  display: block;
}

.page-about .stage {
  position: relative;
  padding: var(--about-stage-pad) 20px 40px;
  border-top: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(14, 26, 51, .0), rgba(14, 26, 51, .0));
}

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

.page-about .stage--v2 {
  background: linear-gradient(180deg, rgba(23, 39, 74, .55) 0%, rgba(14, 26, 51, .35) 100%);
}

.page-about .stage--v3 {
  background: linear-gradient(180deg, rgba(23, 39, 74, .38) 0%, rgba(14, 26, 51, .22) 100%);
}

.page-about .stage--v4 {
  background:
    linear-gradient(180deg, rgba(201, 162, 74, .08) 0%, rgba(14, 26, 51, .5) 100%);
}

.page-about .stage__head {
  margin-bottom: 22px;
}

.page-about .stage__ver {
  margin: 0 0 8px;
  display: inline-block;
  padding: 3px 8px;
  font-family: var(--font-index);
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--ink-950);
  background: var(--sand-500);
}

.page-about .stage--v4 .stage__ver {
  background: var(--sand-300);
}

.page-about .stage__title {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 20px;
  line-height: 1.35;
  color: var(--paper);
}

.page-about .stage__span {
  margin: 0;
  font-family: var(--font-index);
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--sand-700);
}

.page-about .stage__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
}

.page-about .stage__text p {
  margin: 0 0 14px;
  max-width: 38em;
  font-size: 15px;
  line-height: 1.82;
  color: var(--sand-300);
}

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

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

.page-about .stage__figure img,
.page-about .about-sources__figure img,
.page-about .criteria-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border: 1px solid var(--line);
  background: var(--ink-900);
}

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

.page-about .criteria-figure img {
  aspect-ratio: 4 / 5;
}

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

.page-about .figure__cap {
  margin-top: 10px;
  font-size: 12px;
  line-height: 1.7;
  color: var(--mist);
}

/* ---------- 来源 ---------- */
.page-about .about-sources {
  border-bottom: 1px solid var(--line);
}

.page-about .source-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .source-card {
  padding: 22px 20px 24px;
  background: var(--ink-900);
}

.page-about .source-card__no {
  margin: 0 0 10px;
  font-family: var(--font-index);
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--sand-700);
}

.page-about .source-card__title {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 17px;
  color: var(--paper);
}

.page-about .source-card p:last-child {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--sand-300);
}

.page-about .folds {
  margin-top: 32px;
}

.page-about .fold {
  border: 1px solid var(--line);
  background: var(--ink-900);
}

.page-about .fold + .fold {
  margin-top: 12px;
}

.page-about .fold__body p {
  margin: 0 0 12px;
  max-width: 38em;
  font-size: 14px;
  line-height: 1.8;
  color: var(--sand-300);
}

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

.page-about .about-sources__figure {
  margin: 40px 0 0;
}

/* ---------- 收录标准 ---------- */
.page-about .about-criteria {
  border-bottom: 1px solid var(--line);
}

.page-about .criteria-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
}

.page-about .criteria-sub {
  margin: 0 0 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--line);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 15px;
  letter-spacing: .02em;
  color: var(--sand-500);
}

.page-about .criteria-list {
  margin: 0 0 32px;
  padding: 0;
  list-style: none;
}

.page-about .criteria-list li {
  position: relative;
  padding: 10px 0 10px 20px;
  font-size: 14px;
  line-height: 1.75;
  color: var(--sand-300);
  border-bottom: 1px solid var(--grid);
}

.page-about .criteria-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 20px;
  width: 8px;
  height: 1px;
  background: var(--sand-500);
}

.page-about .criteria-list li:last-child {
  margin-bottom: 0;
}

.page-about .criteria-list .num {
  font-family: var(--font-index);
  font-variant-numeric: tabular-nums;
  color: var(--paper);
  letter-spacing: .02em;
}

.page-about .criteria-list--muted li {
  color: var(--mist);
}

.page-about .criteria-list--muted li::before {
  background: var(--sand-700);
}

.page-about .criteria-figure {
  margin: 0;
}

/* ---------- 草皮分隔带 ---------- */
.page-about .grass-band {
  height: 6px;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: repeating-linear-gradient(
    90deg,
    rgba(47, 107, 79, .55) 0 3px,
    rgba(8, 18, 33, .0) 3px 12px
  );
}

/* ---------- 口径版本 ---------- */
.page-about .about-versions {
  border-bottom: 1px solid var(--line);
}

.page-about .table-scroll {
  overflow-x: auto;
  border: 1px solid var(--line);
  background: var(--ink-900);
  -webkit-overflow-scrolling: touch;
}

.page-about .about-table {
  width: 100%;
  min-width: 820px;
  border-collapse: collapse;
  font-size: 13px;
}

.page-about .about-table caption {
  padding: 14px 16px;
  text-align: left;
  font-family: var(--font-index);
  font-size: 11px;
  letter-spacing: .05em;
  color: var(--mist);
  border-bottom: 1px solid var(--line);
  background: var(--ink-950);
}

.page-about .about-table th,
.page-about .about-table td {
  padding: 13px 16px;
  text-align: left;
  vertical-align: top;
  border-bottom: 1px solid var(--grid);
  line-height: 1.6;
  color: var(--sand-300);
}

.page-about .about-table thead th {
  background: var(--ink-800);
  font-family: var(--font-index);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: .08em;
  color: var(--sand-500);
  white-space: nowrap;
}

.page-about .about-table tbody th {
  font-family: var(--font-index);
  font-variant-numeric: tabular-nums;
  font-size: 14px;
  font-weight: 700;
  color: var(--paper);
  white-space: nowrap;
}

.page-about .about-table tbody tr:nth-child(4) th {
  color: var(--sand-500);
}

.page-about .about-table tbody tr:last-child th,
.page-about .about-table tbody tr:last-child td {
  border-bottom: 0;
}

.page-about .about-table tbody tr:hover th,
.page-about .about-table tbody tr:hover td {
  background: rgba(23, 39, 74, .85);
}

/* ---------- 团队 ---------- */
.page-about .about-team {
  border-bottom: 1px solid var(--line);
}

.page-about .team-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .team-cell {
  padding: 20px 18px 22px;
  background: var(--ink-900);
}

.page-about .team-cell__role {
  margin: 0 0 4px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 16px;
  color: var(--paper);
}

.page-about .team-cell__count {
  margin: 0 0 10px;
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--mist);
}

.page-about .team-cell__count .num {
  font-family: var(--font-index);
  font-variant-numeric: tabular-nums;
  font-size: 22px;
  font-weight: 700;
  color: var(--yellow);
}

.page-about .team-cell__desc {
  margin: 0;
  font-size: 13px;
  line-height: 1.75;
  color: var(--sand-300);
}

.page-about .about-team__note {
  margin-top: 32px;
}

/* ---------- 延伸入口 ---------- */
.page-about .about-next {
  padding-bottom: 96px;
}

.page-about .next-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .next-card {
  position: relative;
  display: block;
  padding: 20px 44px 22px 18px;
  background: var(--ink-900);
  text-decoration: none;
  transition: background-color 160ms var(--ease);
}

.page-about .next-card:hover,
.page-about .next-card:focus-visible {
  background: var(--ink-800);
}

.page-about .next-card:focus-visible {
  outline: 2px solid var(--yellow);
  outline-offset: -2px;
}

.page-about .next-card__no {
  margin: 0 0 8px;
  font-family: var(--font-index);
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--sand-700);
}

.page-about .next-card__label {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--sand-300);
}

.page-about .next-card__arrow {
  position: absolute;
  right: 18px;
  top: 50%;
  transform: translateY(-50%);
  font-family: var(--font-index);
  font-size: 16px;
  color: var(--sand-500);
}

.page-about .about-next__trust {
  margin: 28px 0 0;
  max-width: 52em;
  padding: 16px 18px;
  border-left: 2px solid var(--green);
  background: rgba(47, 107, 79, .12);
  font-size: 13px;
  line-height: 1.78;
  color: var(--sand-300);
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .about-hero h1 {
    font-size: 42px;
  }

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

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

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

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

@media (min-width: 900px) {
  .page-about .section {
    padding: 96px 0;
  }

  .page-about .about-hero {
    padding: 32px 0 72px;
  }

  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 56px;
  }

  .page-about .about-hero h1 {
    font-size: 52px;
  }

  /* 编年长卷：左缘赛季刻度尺 */
  .page-about .ledger {
    padding-left: var(--about-rail-w);
  }

  .page-about .ledger__rail {
    display: block;
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: calc(var(--about-rail-w) - 20px);
    border-right: 1px solid var(--line);
  }

  .page-about .ledger__rail::after {
    content: "";
    position: absolute;
    right: -8px;
    top: 0;
    bottom: 0;
    width: 15px;
    background: repeating-linear-gradient(
      to bottom,
      var(--line-strong) 0 1px,
      transparent 1px 24px
    );
    opacity: .55;
    pointer-events: none;
  }

  .page-about .ledger__rail-in {
    position: sticky;
    top: 96px;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    height: 340px;
    padding-right: 16px;
  }

  .page-about .ledger__year {
    font-family: var(--font-index);
    font-variant-numeric: tabular-nums;
    font-size: 12px;
    letter-spacing: .06em;
    color: var(--sand-700);
    text-align: right;
    transition: color 160ms var(--ease);
  }

  .page-about .ledger__rail-in .ledger__year:first-child,
  .page-about .ledger__rail-in .ledger__year:last-child {
    color: var(--sand-500);
  }

  .page-about .stage {
    padding: 44px 0 52px;
  }

  .page-about .stage__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 40px;
    align-items: start;
  }

  .page-about .stage__grid--narrow {
    grid-template-columns: minmax(0, 8fr) minmax(0, 4fr);
  }

  .page-about .criteria-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 48px;
    align-items: start;
  }

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

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

  .page-about .about-sources__figure {
    margin-top: 48px;
  }
}

@media (min-width: 1180px) {
  .page-about .about-hero h1 {
    font-size: 56px;
  }

  .page-about .section__title {
    font-size: 30px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .next-card,
  .page-about .ledger__year {
    transition: none;
  }
}