.page-about {
  --about-rail: 132px;
  --about-read: 720px;
  display: block;
  background: var(--pearl);
  color: var(--ink);
}

/* ---------- 面包屑与首屏 ---------- */

.page-about .breadcrumb {
  padding-top: 28px;
}

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

.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
  padding-top: 40px;
  padding-bottom: 32px;
  align-items: end;
}

.page-about .about-hero__kicker {
  color: var(--orange-text);
  margin: 0 0 14px;
}

.page-about .about-hero__title {
  margin: 0 0 18px;
  font-size: 34px;
  line-height: 1.18;
  letter-spacing: -0.02em;
  font-weight: 900;
  color: var(--deep);
  max-width: 18ch;
}

.page-about .about-hero__lede {
  margin: 0;
  max-width: 60ch;
  color: var(--ink);
}

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

.page-about .about-hero__year {
  margin: 6px 0 10px;
  font-family: var(--font-mono);
  font-weight: 300;
  font-size: 68px;
  line-height: .95;
  letter-spacing: -0.05em;
  color: var(--deep);
  font-variant-numeric: tabular-nums;
}

.page-about .about-hero__note {
  margin: 0;
  font-size: 13px;
  line-height: 1.7;
  color: var(--graphite);
}

.page-about .about-scale {
  display: flex;
  align-items: center;
  gap: 0;
  padding: 18px 0 26px;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .about-scale__mark {
  flex: 0 0 auto;
  width: 44px;
  height: 1px;
  background: var(--orange);
  margin-right: 14px;
}

.page-about .about-scale__tick {
  flex: 0 0 auto;
  position: relative;
  padding: 0 26px 0 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--graphite);
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}

.page-about .about-scale__tick::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  width: 1px;
  height: 10px;
  transform: translateY(-50%);
  background: var(--line-strong);
}

.page-about .about-scale__tick--end {
  color: var(--orange-text);
}

.page-about .about-scale__tick--end::before {
  background: var(--orange);
  height: 16px;
}

/* ---------- 章节索引带 ---------- */

.page-about .about-toc {
  border-bottom: 1px solid var(--line);
  background: var(--mist);
}

.page-about .about-toc__list {
  display: flex;
  align-items: stretch;
  gap: 0;
  margin: 0;
  padding: 0;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .about-toc__link {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 14px 20px;
  white-space: nowrap;
  font-size: 13px;
  letter-spacing: .04em;
  color: var(--graphite);
  text-decoration: none;
  border-right: 1px solid var(--line);
  transition: color var(--dur) var(--ease), background-color var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}

.page-about .about-toc__link:hover {
  color: var(--deep);
  background: rgba(11, 42, 74, .04);
}

.page-about .about-toc__link[aria-current="true"] {
  color: var(--deep);
  box-shadow: inset 0 -2px 0 var(--orange);
}

.page-about .about-toc__num {
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--orange-text);
  font-variant-numeric: tabular-nums;
}

/* ---------- 面板骨架 ---------- */

.page-about .about-panel {
  border-bottom: 1px solid var(--line);
  padding-top: 48px;
  padding-bottom: 48px;
}

.page-about .about-panel--mist {
  background: var(--mist);
}

.page-about .about-panel--deep {
  background: var(--deep);
  border-bottom-color: rgba(247, 248, 246, .14);
}

.page-about .about-panel__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
}

.page-about .about-panel__rail {
  display: flex;
  align-items: baseline;
  gap: 14px;
}

.page-about .about-panel__num {
  font-family: var(--font-mono);
  font-weight: 300;
  font-size: 44px;
  line-height: 1;
  letter-spacing: -0.04em;
  color: var(--deep);
  opacity: .22;
  font-variant-numeric: tabular-nums;
}

.page-about .about-panel__rail-label {
  color: var(--graphite);
}

.page-about .about-panel__content {
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 22px;
}

.page-about .about-h2 {
  margin: 0;
  font-size: 24px;
  line-height: 1.3;
  letter-spacing: -0.02em;
  font-weight: 900;
  color: var(--deep);
  max-width: 22ch;
}

.page-about .about-h2--invert {
  color: var(--pearl);
}

.page-about .about-lede {
  margin: 0;
  font-size: 16px;
  line-height: 1.85;
  color: var(--ink);
  max-width: 64ch;
}

.page-about .about-lede--invert {
  color: rgba(247, 248, 246, .8);
}

/* ---------- 媒体 ---------- */

.page-about .about-media {
  margin: 0;
  border: 1px solid var(--line);
  background: var(--mist);
  position: relative;
  overflow: hidden;
}

.page-about .about-media img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
}

.page-about .about-media::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 40px;
  height: 3px;
  background: var(--orange);
}

.page-about .about-media .media__cap {
  margin: 0;
  padding: 10px 14px 12px;
  font-size: 12px;
  line-height: 1.7;
  color: var(--graphite);
  border-top: 1px solid var(--line);
  background: var(--pearl);
}

.page-about .about-media--lead {
  max-width: 100%;
}

.page-about .about-media--team {
  max-width: 100%;
}

.page-about .about-media--wide {
  max-width: 100%;
}

/* ---------- 时间线 ---------- */

.page-about .about-timeline {
  list-style: none;
  margin: 8px 0 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.page-about .about-timeline__item {
  display: grid;
  grid-template-columns: 78px minmax(0, 1fr);
  gap: 14px;
  padding: 18px 0;
  border-bottom: 1px solid var(--line);
  transition: border-color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.page-about .about-timeline__item:hover {
  border-bottom-color: var(--orange);
  background: rgba(255, 107, 53, .04);
}

.page-about .about-timeline__year {
  font-family: var(--font-mono);
  font-weight: 300;
  font-size: 27px;
  line-height: 1.1;
  letter-spacing: -0.03em;
  color: var(--deep);
  font-variant-numeric: tabular-nums;
}

.page-about .about-timeline__year::after {
  content: "";
  display: block;
  width: 1px;
  height: 16px;
  margin-top: 8px;
  background: var(--orange);
}

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

.page-about .about-timeline__tag {
  margin: 0 0 4px;
  color: var(--orange-text);
}

.page-about .about-timeline__body p:last-child {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--ink);
  max-width: 62ch;
}

/* ---------- 双栏叙事 ---------- */

.page-about .about-split {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
}

.page-about .about-split__col {
  margin: 0;
  font-size: 16px;
  line-height: 1.9;
  color: var(--ink);
  max-width: 60ch;
}

.page-about .about-split__col--offset {
  color: var(--graphite);
}

/* ---------- 六类口径 ---------- */

.page-about .about-reasons {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  margin-top: 6px;
}

.page-about .about-reason {
  background: var(--pearl);
  padding: 22px 20px;
}

.page-about .about-panel--mist .about-reason {
  background: var(--pearl);
}

.page-about .about-reason__code {
  display: inline-block;
  padding: 2px 8px;
  margin-bottom: 12px;
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--gold-text);
  border: 1px solid var(--gold);
  font-variant-numeric: tabular-nums;
}

.page-about .about-reason h3 {
  margin: 0 0 8px;
  font-size: 17px;
  line-height: 1.4;
  font-weight: 700;
  color: var(--deep);
}

.page-about .about-reason p {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--graphite);
}

/* ---------- 三组分工 ---------- */

.page-about .about-teams {
  display: grid;
  grid-template-columns: 1fr;
  gap: 26px;
  margin-top: 4px;
}

.page-about .about-team {
  border-top: 1px solid var(--line-strong);
  padding-top: 16px;
}

.page-about .about-team__count {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-weight: 300;
  font-size: 48px;
  line-height: 1;
  letter-spacing: -0.04em;
  color: var(--deep);
  font-variant-numeric: tabular-nums;
}

.page-about .about-team__unit {
  font-size: 13px;
  letter-spacing: .14em;
  color: var(--graphite);
  margin-left: 6px;
}

.page-about .about-team__title {
  margin: 0 0 10px;
  font-size: 17px;
  line-height: 1.4;
  font-weight: 700;
  color: var(--orange-text);
}

.page-about .about-team__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--ink);
}

/* ---------- 深色数据面板 ---------- */

.page-about .about-panel--deep .about-panel__num {
  color: var(--pearl);
  opacity: .26;
}

.page-about .about-panel--deep .about-panel__rail-label {
  color: var(--orange-mist);
}

.page-about .about-figures {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: rgba(247, 248, 246, .16);
  border: 1px solid rgba(247, 248, 246, .16);
  margin-top: 6px;
}

.page-about .about-figures__item {
  background: var(--deep);
  padding: 18px 16px 20px;
}

.page-about .about-figures__value {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-weight: 300;
  font-size: 38px;
  line-height: 1;
  letter-spacing: -0.04em;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}

.page-about .about-figures__unit {
  font-size: 13px;
  letter-spacing: .12em;
  color: rgba(247, 248, 246, .72);
  margin-left: 5px;
}

.page-about .about-figures__label {
  margin: 0;
  font-size: 13px;
  line-height: 1.7;
  color: rgba(247, 248, 246, .7);
}

.page-about .about-procedure {
  margin: 12px 0 0;
  padding: 0;
  border-top: 1px solid rgba(247, 248, 246, .16);
}

.page-about .about-procedure__row {
  display: grid;
  grid-template-columns: 1fr;
  gap: 6px;
  padding: 16px 0;
  border-bottom: 1px solid rgba(247, 248, 246, .16);
}

.page-about .about-procedure__row dt {
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--orange-mist);
}

.page-about .about-procedure__row dd {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: rgba(247, 248, 246, .84);
  max-width: 68ch;
}

/* ---------- 斜线与子栏目入口 ---------- */

.page-about .about-slant {
  display: block;
  width: min(100%, 400px);
  height: 40px;
  color: var(--orange);
  margin: 4px 0 0;
}

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

.page-about .about-route {
  display: flex;
  flex-direction: column;
  gap: 6px;
  background: var(--pearl);
  padding: 22px 20px;
  text-decoration: none;
  color: inherit;
  transition: background-color var(--dur) var(--ease), outline-color var(--dur) var(--ease);
  outline: 1px solid transparent;
  outline-offset: -1px;
}

.page-about .about-route:hover,
.page-about .about-route:focus-visible {
  background: var(--pearl);
  outline-color: var(--orange);
}

.page-about .about-route__num {
  color: var(--gold-text);
}

.page-about .about-route__title {
  font-size: 19px;
  font-weight: 900;
  letter-spacing: -0.01em;
  color: var(--deep);
}

.page-about .about-route__desc {
  font-size: 14px;
  line-height: 1.8;
  color: var(--graphite);
}

/* ---------- 平板 ---------- */

@media (min-width: 720px) {
  .page-about .about-hero__title {
    font-size: 44px;
  }

  .page-about .about-hero__year {
    font-size: 84px;
  }

  .page-about .about-h2 {
    font-size: 30px;
  }

  .page-about .about-split {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 32px;
    align-items: start;
  }

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

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

  .page-about .about-teams {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 28px;
  }

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

  .page-about .about-procedure__row {
    grid-template-columns: 150px minmax(0, 1fr);
    gap: 24px;
    align-items: baseline;
  }
}

/* ---------- 桌面 ---------- */

@media (min-width: 960px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.5fr) minmax(0, 0.5fr);
    gap: 64px;
    padding-top: 68px;
    padding-bottom: 44px;
  }

  .page-about .about-hero__title {
    font-size: 56px;
    max-width: 20ch;
  }

  .page-about .about-hero__year {
    font-size: 104px;
  }

  .page-about .about-panel {
    padding-top: 64px;
    padding-bottom: 64px;
  }

  .page-about .about-panel__grid {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: 52px;
  }

  .page-about .about-panel__rail {
    flex-direction: column;
    gap: 12px;
    border-right: 1px solid var(--line);
    padding-right: 24px;
  }

  .page-about .about-panel--deep .about-panel__rail {
    border-right-color: rgba(247, 248, 246, .16);
  }

  .page-about .about-panel__num {
    font-size: 88px;
  }

  .page-about .about-panel__content {
    gap: 28px;
  }

  .page-about .about-h2 {
    font-size: 34px;
    max-width: 26ch;
  }

  .page-about .about-timeline__item {
    grid-template-columns: 168px minmax(0, 1fr);
    gap: 36px;
    padding: 26px 0;
  }

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

  .page-about .about-timeline__body p:last-child {
    font-size: 16px;
  }

  .page-about .about-media--lead {
    width: calc(100% + 96px);
    max-width: none;
  }

  .page-about .about-media--team {
    width: min(100%, 560px);
  }

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

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

  .page-about .about-figures__value {
    font-size: 46px;
  }

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

/* ---------- 宽屏错位 ---------- */

@media (min-width: 1200px) {
  .page-about .about-panel__grid--indent {
    padding-left: calc(var(--page-x) + 56px);
  }

  .page-about .about-split__col {
    max-width: 46ch;
  }

  .page-about .about-hero__lede {
    max-width: 66ch;
  }

  .page-about .about-media--wide {
    width: calc(100% + 120px);
    max-width: none;
  }
}
<<<END>>>