.page-about {
  --about-glow: rgba(52, 231, 228, .16);
  --about-hair: rgba(28, 92, 107, .58);
  background-color: var(--night);
  background-image:
    linear-gradient(rgba(107, 118, 144, .055) 1px, transparent 1px),
    linear-gradient(90deg, rgba(107, 118, 144, .055) 1px, transparent 1px);
  background-size: 64px 64px;
  color: var(--paper);
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumbs {
  padding-top: clamp(16px, 3vw, 30px);
  font-size: 13px;
  letter-spacing: .04em;
}

.page-about .breadcrumbs__list {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin: 0;
  padding: 0;
  list-style: none;
  color: var(--mist-lift);
}

.page-about .breadcrumbs__list li + li::before {
  content: "/";
  margin-right: 6px;
  color: var(--mist);
}

.page-about .breadcrumbs__list a {
  color: var(--mist-lift);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .breadcrumbs__list a:hover,
.page-about .breadcrumbs__list a:focus-visible {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

/* ---------- 开篇 ---------- */
.page-about .about-intro {
  padding-top: clamp(34px, 5.5vw, 68px);
}

.page-about .about-intro__title {
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(34px, 6vw, 66px);
  line-height: 1.08;
  letter-spacing: -.012em;
  margin: 16px 0 0;
  max-width: 17ch;
}

.page-about .about-intro__lede {
  max-width: 60ch;
  margin-top: 24px;
  font-size: clamp(16px, 1.1vw + 12px, 19px);
  line-height: 1.9;
  color: var(--mist-lift);
}

.page-about .about-intro__marks {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 30px;
  margin: 36px 0 0;
  padding: 22px 0 0;
  border-top: 1px solid var(--line);
  list-style: none;
  font-size: 13px;
  letter-spacing: .05em;
  color: var(--mist-lift);
}

.page-about .about-intro__marks li {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
}

.page-about .about-intro__marks .mono {
  font-size: 21px;
  font-weight: 600;
  color: var(--orange);
  letter-spacing: -.01em;
}

/* ---------- 区块节奏 ---------- */
.page-about .section {
  padding-block: clamp(56px, 7.5vw, 106px);
}

.page-about .section--tight {
  padding-block: clamp(30px, 4.5vw, 58px);
}

.page-about .section-head {
  margin-bottom: clamp(28px, 4vw, 50px);
}

.page-about .section-head .muted {
  margin-top: 12px;
  max-width: 56ch;
  font-size: 15px;
  line-height: 1.8;
}

.page-about .block-title {
  max-width: 22ch;
  line-height: 1.22;
}

/* ---------- 非对称双栏 ---------- */
.page-about .about-split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 4vw, 58px);
  align-items: start;
}

.page-about .about-split__body > .prose p + p {
  margin-top: 18px;
}

.page-about .about-split__body .prose p {
  color: var(--mist-lift);
  line-height: 1.9;
}

.page-about .about-split__body .prose p:first-child {
  color: var(--paper);
}

/* ---------- 数字卡 ---------- */
.page-about .about-metrics {
  display: grid;
  gap: 12px;
}

.page-about .metric {
  position: relative;
  padding: 18px 18px 18px 20px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-left: 3px solid var(--edge);
  outline-offset: 5px;
  transition: border-left-color var(--dur) var(--ease),
              transform var(--dur) var(--ease),
              box-shadow var(--dur) var(--ease);
}

.page-about .metric:hover,
.page-about .metric:focus {
  border-left-color: var(--cyan);
  transform: translateX(4px);
  box-shadow: -10px 0 24px -14px var(--about-glow);
}

.page-about .metric__value {
  display: block;
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: clamp(30px, 4.6vw, 42px);
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--orange);
}

.page-about .metric__label {
  display: block;
  margin-top: 9px;
  font-size: 12.5px;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--mist-lift);
}

.page-about .metric__hint {
  margin: 0;
  max-height: 0;
  opacity: 0;
  overflow: hidden;
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--mist-lift);
  transition: max-height var(--dur) var(--ease),
              opacity var(--dur) var(--ease),
              margin var(--dur) var(--ease);
}

.page-about .metric:hover .metric__hint,
.page-about .metric:focus .metric__hint,
.page-about .metric:focus-within .metric__hint {
  max-height: 8em;
  opacity: 1;
  margin-top: 10px;
}

/* ---------- 图片框微调 ---------- */
.page-about .figure-frame {
  margin: 0;
}

.page-about .figure-frame__media {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--about-hair);
}

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

.page-about .figure-frame__caption {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--mist);
}

.page-about .about-team__figure {
  margin-top: clamp(26px, 3.5vw, 40px);
}

/* ---------- 时间带 ---------- */
.page-about .about-history__figure {
  margin: 0 0 clamp(40px, 5.5vw, 68px);
}

.page-about .about-timeline {
  margin-top: clamp(30px, 4vw, 54px);
}

.page-about .about-timeline__list {
  position: relative;
  margin: 0;
  padding: 0;
  list-style: none;
  border-left: 1px solid var(--line);
}

.page-about .about-timeline__item {
  position: relative;
  padding: 0 0 30px 26px;
  outline-offset: 5px;
}

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  left: -5px;
  top: 5px;
  width: 9px;
  height: 9px;
  background: var(--night);
  border: 2px solid var(--cyan);
}

.page-about .about-timeline__item:last-child {
  padding-bottom: 0;
}

.page-about .about-timeline__gen {
  display: block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .18em;
  color: var(--orange);
}

.page-about .about-timeline__item .label-chip {
  display: inline-block;
  margin-bottom: 10px;
}

.page-about .about-timeline__note {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--mist-lift);
}

/* ---------- 数据来源 ---------- */
.page-about .about-source {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(28px, 4vw, 56px);
  align-items: start;
}

.page-about .about-source__body p {
  color: var(--mist-lift);
  line-height: 1.9;
}

.page-about .about-source__body p + p {
  margin-top: 18px;
}

.page-about .about-source__body p:first-child {
  color: var(--paper);
}

.page-about .about-strip {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 1px;
  margin-top: 30px;
  border: 1px solid var(--line);
  background: var(--line);
}

.page-about .about-strip__cell {
  background: var(--coal);
  padding: 16px 18px;
}

.page-about .about-strip__num {
  display: block;
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: 28px;
  line-height: 1;
  color: var(--cyan);
}

.page-about .about-strip__cap {
  display: block;
  margin-top: 9px;
  font-size: 12.5px;
  line-height: 1.6;
  letter-spacing: .04em;
  color: var(--mist-lift);
}

/* ---------- 合作生态大数字 ---------- */
.page-about .about-counts {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  border: 1px solid var(--line);
  background: var(--line);
}

.page-about .about-counts__item {
  background: var(--coal);
  padding: clamp(20px, 3vw, 30px);
}

.page-about .about-counts__num {
  display: block;
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: clamp(46px, 8vw, 74px);
  line-height: .9;
  letter-spacing: -.03em;
  color: var(--cyan);
}

.page-about .about-counts__text {
  margin: 14px 0 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--mist-lift);
}

/* ---------- 运营事实行 ---------- */
.page-about .about-facts {
  display: grid;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.page-about .about-facts__row {
  display: grid;
  gap: 8px;
  padding: 22px 0;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-facts dt {
  font-family: var(--font-head);
  font-weight: 900;
  font-size: 15px;
  letter-spacing: .06em;
  color: var(--paper);
}

.page-about .about-facts dd {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--mist-lift);
}

/* ---------- 审核纸张叠层 ---------- */
.page-about .about-audit {
  position: relative;
  padding: clamp(24px, 4vw, 46px);
  border: 1px solid var(--edge);
  background: rgba(20, 22, 28, .94);
  box-shadow: 10px 10px 0 rgba(28, 92, 107, .3), 20px 20px 0 rgba(28, 92, 107, .14);
}

.page-about .about-audit .lede {
  max-width: 58ch;
  font-size: 16.5px;
  line-height: 1.9;
  color: var(--paper);
}

.page-about .about-audit__steps {
  margin: clamp(22px, 3vw, 32px) 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 14px;
  counter-reset: audit;
}

.page-about .about-audit__steps li {
  position: relative;
  padding-left: 48px;
  font-size: 15px;
  line-height: 1.85;
  color: var(--mist-lift);
  counter-increment: audit;
}

.page-about .about-audit__steps li::before {
  content: "0" counter(audit);
  position: absolute;
  left: 0;
  top: 3px;
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: .06em;
  color: var(--rose);
}

.page-about .about-audit__tail {
  margin: clamp(20px, 3vw, 28px) 0 0;
  padding-top: clamp(18px, 2.5vw, 24px);
  border-top: 1px solid var(--line-soft);
  font-size: 15px;
  line-height: 1.85;
  color: var(--mist-lift);
}

/* ---------- 收尾 ---------- */
.page-about .about-next {
  border-top: 1px solid var(--line);
  padding-bottom: clamp(64px, 8vw, 110px);
}

.page-about .about-next__lede {
  max-width: 58ch;
  margin-top: 18px;
  font-size: 16.5px;
  line-height: 1.9;
  color: var(--mist-lift);
}

.page-about .about-next__links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 30px;
}

/* ---------- 桌面端 ---------- */
@media (min-width: 900px) {
  .page-about .about-split {
    grid-template-columns: minmax(180px, 4fr) minmax(0, 8fr);
  }

  .page-about .about-source {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
  }

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

  .page-about .metric__value {
    font-size: 44px;
  }
}

@media (min-width: 880px) {
  .page-about .about-timeline__list {
    display: grid;
    grid-template-columns: repeat(6, minmax(0, 1fr));
    border-left: 0;
  }

  .page-about .about-timeline__item {
    padding: 38px 20px 0 0;
  }

  .page-about .about-timeline__item::before {
    left: 0;
    top: -4px;
    transition: background var(--dur) var(--ease), border-color var(--dur) var(--ease);
  }

  .page-about .about-timeline__item::after {
    content: "";
    position: absolute;
    left: 0;
    right: 0;
    top: 0;
    height: 1px;
    background: var(--line);
  }

  .page-about .about-timeline__item:last-child::after {
    display: none;
  }

  .page-about .about-timeline__note {
    max-height: 0;
    opacity: 0;
    overflow: hidden;
    transition: max-height var(--dur) var(--ease), opacity var(--dur) var(--ease);
  }

  .page-about .about-timeline__item:hover .about-timeline__note,
  .page-about .about-timeline__item:focus .about-timeline__note,
  .page-about .about-timeline__item:focus-within .about-timeline__note {
    max-height: 9em;
    opacity: 1;
  }

  .page-about .about-timeline__item:hover::before,
  .page-about .about-timeline__item:focus::before {
    background: var(--cyan);
    border-color: var(--cyan);
  }

  .page-about .about-timeline__item:hover .about-timeline__gen,
  .page-about .about-timeline__item:focus .about-timeline__gen {
    color: var(--cyan);
  }
}

@media (min-width: 760px) {
  .page-about .about-facts__row {
    grid-template-columns: minmax(130px, 3fr) minmax(0, 9fr);
    gap: 6px 32px;
    align-items: baseline;
  }
}

@media (min-width: 720px) {
  .page-about .about-counts {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

/* ---------- 减少动态偏好 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .metric,
  .page-about .metric__hint,
  .page-about .about-timeline__note,
  .page-about .about-timeline__item::before,
  .page-about .about-timeline__gen,
  .page-about .breadcrumbs__list a {
    transition-duration: .01ms !important;
  }

  .page-about .metric:hover,
  .page-about .metric:focus {
    transform: none;
  }

  .page-about .metric__hint,
  .page-about .about-timeline__note {
    max-height: none;
    opacity: 1;
    overflow: visible;
  }
}