.page-about {
  --pa-tl-year: 84px;
  --pa-tl-gap: clamp(20px, 4vw, 52px);
  --pa-rule: 1.5px;
}

/* ---------- 页首 ---------- */
.page-about .page-head {
  display: block;
  padding: clamp(20px, 3vw, 36px) 0 clamp(28px, 5vw, 56px);
}

.page-about .page-head__title {
  max-width: 18ch;
  margin: 14px 0 0;
  font-family: var(--font-serif);
  font-weight: 300;
  font-size: clamp(34px, 7.4vw, 68px);
  line-height: 1.05;
  letter-spacing: -0.02em;
  color: var(--charcoal);
}

.page-about .page-head__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 16px;
  align-items: center;
  margin-top: 22px;
}

/* ---------- 立场声明 ---------- */
.page-about .about-stance {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(16px, 3vw, 28px);
  border-top: var(--pa-rule) solid var(--charcoal);
  padding-top: clamp(24px, 4vw, 44px);
}

.page-about .about-stance__aside {
  display: flex;
  flex-direction: row;
  gap: 16px;
  align-items: baseline;
}

.page-about .about-stance__main .statement {
  margin: 0 0 20px;
  font-family: var(--font-serif);
  font-weight: 300;
  font-size: clamp(24px, 4.4vw, 38px);
  line-height: 1.24;
  letter-spacing: -0.02em;
  color: var(--ink);
}

/* ---------- 时间线 ---------- */
.page-about .about-track {
  position: relative;
}

.page-about .timeline {
  list-style: none;
  margin: clamp(20px, 3vw, 32px) 0 0;
  padding: 0;
}

.page-about .timeline__item {
  display: grid;
  grid-template-columns: 1fr;
  row-gap: 10px;
  position: relative;
  padding: 26px 0;
  border-bottom: var(--pa-rule) solid var(--silver-line);
  scroll-margin-top: 120px;
}

.page-about .timeline__item:first-child {
  border-top: var(--pa-rule) solid var(--silver-line);
}

.page-about .timeline__marker {
  display: flex;
  align-items: baseline;
  gap: 12px;
  text-decoration: none;
  color: inherit;
  border: 0;
}

.page-about .timeline__marker:focus-visible {
  outline: 2px solid var(--amber);
  outline-offset: 4px;
}

.page-about .timeline__year {
  font-size: clamp(20px, 3vw, 26px);
  font-weight: 500;
  letter-spacing: 0.04em;
  color: var(--charcoal);
  transition: color var(--dur) var(--ease);
}

.page-about .timeline__code {
  color: var(--silver-ink);
}

.page-about .timeline__title {
  margin: 0 0 8px;
  font-family: var(--font-serif);
  font-weight: 400;
  font-size: clamp(19px, 2.4vw, 24px);
  line-height: 1.3;
  color: var(--ink);
}

.page-about .timeline__desc {
  margin: 0;
  max-width: 68ch;
  font-size: 15px;
  line-height: 1.75;
  color: var(--charcoal);
}

.page-about .timeline__note {
  margin: 12px 0 0;
  color: var(--silver-ink);
  transition: color var(--dur) var(--ease);
}

.page-about .timeline__item:hover .timeline__note,
.page-about .timeline__item:focus-within .timeline__note {
  color: var(--charcoal);
}

.page-about .timeline__item:hover .timeline__year {
  color: var(--amber-deep);
}

.page-about .timeline__item:target {
  background: linear-gradient(90deg, rgba(231, 179, 76, 0.14), rgba(231, 179, 76, 0) 64%);
}

.page-about .timeline__item:target .timeline__year {
  color: var(--amber-deep);
}

.page-about .about-track__media {
  margin: clamp(28px, 4vw, 48px) 0 0;
}

/* ---------- 团队（墨绿分区） ---------- */
.page-about .about-team {
  position: relative;
}

.page-about .about-team .section__title {
  color: var(--paper);
}

.page-about .about-team .section__index,
.page-about .about-team .section__note {
  color: rgba(244, 241, 234, 0.68);
}

.page-about .about-team__media {
  margin: 0 0 clamp(28px, 4vw, 44px);
}

.page-about .team {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid rgba(244, 241, 234, 0.28);
}

.page-about .team__row {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: baseline;
  gap: 8px 16px;
  padding: 20px 0;
  border-bottom: 1px solid rgba(244, 241, 234, 0.18);
}

.page-about .team__name {
  font-family: var(--font-serif);
  font-weight: 400;
  font-size: 17px;
  color: var(--paper);
}

.page-about .team__count {
  font-size: 18px;
  font-weight: 500;
  letter-spacing: 0.04em;
  color: var(--apricot);
}

.page-about .team__track {
  grid-column: 1 / -1;
  display: block;
  position: relative;
  height: 8px;
  background: rgba(244, 241, 234, 0.14);
  overflow: hidden;
}

.page-about .team__fill {
  display: block;
  height: 100%;
  width: var(--fill, 0%);
  background: var(--amber);
  transition: background var(--dur) var(--ease);
}

.page-about .team__row:hover .team__fill {
  background: var(--apricot);
}

.page-about .team__duty {
  grid-column: 1 / -1;
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: rgba(244, 241, 234, 0.74);
}

.page-about .about-team__foot {
  margin: clamp(22px, 3vw, 32px) 0 0;
  color: rgba(244, 241, 234, 0.62);
}

/* ---------- 验收等级 ---------- */
.page-about .levels {
  list-style: none;
  margin: clamp(22px, 3vw, 34px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
  border: var(--pa-rule) solid var(--charcoal);
  background: var(--paper-light);
}

.page-about .level {
  padding: clamp(20px, 3vw, 28px);
  border-bottom: var(--pa-rule) solid var(--silver-line);
  position: relative;
}

.page-about .level:last-child {
  border-bottom: 0;
}

.page-about .level::before {
  content: "";
  display: block;
  width: var(--level-bar, 12%);
  height: 6px;
  background: var(--amber);
  margin-bottom: 16px;
}

.page-about .level:nth-child(1)::before { --level-bar: 16%; }
.page-about .level:nth-child(2)::before { --level-bar: 40%; }
.page-about .level:nth-child(3)::before { --level-bar: 68%; }
.page-about .level:nth-child(4)::before { --level-bar: 100%; }

.page-about .level__code {
  margin: 0 0 8px;
  font-size: 22px;
  font-weight: 500;
  letter-spacing: 0.06em;
  color: var(--ink);
}

.page-about .level__name {
  margin: 0 0 8px;
  font-family: var(--font-serif);
  font-weight: 400;
  font-size: 19px;
  line-height: 1.3;
  color: var(--charcoal);
}

.page-about .level__scene {
  margin: 0 0 10px;
  color: var(--amber-deep);
}

.page-about .level__desc {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--charcoal);
}

.page-about .levels-note {
  margin-top: clamp(26px, 4vw, 44px);
  padding-top: clamp(20px, 3vw, 28px);
  border-top: var(--pa-rule) solid var(--charcoal);
}

/* ---------- 业务边界 ---------- */
.page-about .boundary {
  list-style: none;
  margin: clamp(22px, 3vw, 34px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
  border-top: var(--pa-rule) solid var(--charcoal);
}

.page-about .boundary__item {
  padding: 20px 0 20px 18px;
  border-bottom: var(--pa-rule) solid rgba(22, 21, 19, 0.28);
  border-left: 4px solid var(--check);
  transition: background var(--dur) var(--ease);
}

.page-about .boundary__item:hover {
  background: rgba(179, 66, 42, 0.06);
}

.page-about .boundary__title {
  margin: 0 0 8px;
  font-family: var(--font-serif);
  font-weight: 400;
  font-size: 18px;
  line-height: 1.32;
  color: var(--charcoal);
}

.page-about .boundary__desc {
  margin: 0;
  max-width: 66ch;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--charcoal);
}

.page-about .about-boundary__actions {
  margin-top: clamp(22px, 3vw, 32px);
}

/* ---------- 属地与合规 ---------- */
.page-about .about-territory__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(24px, 4vw, 48px);
  margin-top: clamp(20px, 3vw, 32px);
}

.page-about .about-territory__panel {
  margin: 24px 0 0;
}

.page-about .about-territory__actions {
  margin-top: 24px;
}

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

/* ---------- 继续查阅（炭黑分区） ---------- */
.page-about .about-more .section__title {
  color: var(--paper);
}

.page-about .about-more .section__index,
.page-about .about-more .section__note {
  color: rgba(244, 241, 234, 0.66);
}

.page-about .about-more__list {
  margin-top: clamp(20px, 3vw, 30px);
}

.page-about .about-more .toc__link {
  border-color: rgba(244, 241, 234, 0.22);
  color: var(--paper);
}

.page-about .about-more .toc__link:hover {
  border-color: var(--amber);
}

.page-about .about-more .toc__no {
  color: var(--apricot);
}

.page-about .about-more .toc__meta {
  color: rgba(244, 241, 234, 0.74);
}

/* ---------- 响应式 ---------- */
@media (min-width: 700px) {
  .page-about .about-stance {
    grid-template-columns: minmax(0, 1fr) minmax(0, 2.4fr);
    gap: clamp(24px, 5vw, 76px);
  }

  .page-about .about-stance__aside {
    flex-direction: column;
    gap: 8px;
  }

  .page-about .timeline__item {
    grid-template-columns: var(--pa-tl-year) minmax(0, 1fr);
    column-gap: var(--pa-tl-gap);
    row-gap: 0;
    padding: 30px 0;
  }

  .page-about .timeline__item::before {
    content: "";
    position: absolute;
    top: 0;
    bottom: 0;
    left: calc(var(--pa-tl-year) + var(--pa-tl-gap) / 2);
    width: var(--pa-rule);
    background: var(--silver-line);
  }

  .page-about .timeline__item::after {
    content: "";
    position: absolute;
    top: 38px;
    left: calc(var(--pa-tl-year) + var(--pa-tl-gap) / 2);
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--paper);
    border: 2px solid var(--moss);
    transform: translateX(-50%);
    transition: background var(--dur) var(--ease), border-color var(--dur) var(--ease);
    z-index: 1;
  }

  .page-about .timeline__item:hover::after,
  .page-about .timeline__item:focus-within::after {
    background: var(--amber);
    border-color: var(--amber-deep);
  }

  .page-about .timeline__item:target::after {
    background: var(--amber);
    border-color: var(--amber-deep);
  }

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

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

  .page-about .level {
    border-bottom: 0;
    border-right: var(--pa-rule) solid var(--silver-line);
  }

  .page-about .level:last-child {
    border-right: 0;
  }

  .page-about .boundary {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: clamp(24px, 4vw, 48px);
  }

  .page-about .about-territory__grid {
    grid-template-columns: minmax(0, 1.5fr) minmax(0, 1fr);
    align-items: start;
  }
}

@media (min-width: 1024px) {
  .page-about .page-head__title {
    max-width: 20ch;
  }

  .page-about .about-territory__grid {
    grid-template-columns: minmax(0, 1.7fr) minmax(0, 1fr);
    gap: clamp(40px, 6vw, 96px);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .timeline__year,
  .page-about .timeline__note,
  .page-about .team__fill,
  .page-about .boundary__item,
  .page-about .timeline__item::after {
    transition: none;
  }
}

.page-about {
  --fill: currentColor;
}