.page-about {
  --ab-space: clamp(44px, 7vw, 92px);
  --ab-tight: clamp(28px, 4vw, 48px);
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 0 var(--pad-x) clamp(52px, 8vw, 104px);
  font-family: var(--font-body);
  font-size: var(--fs-body);
  line-height: 1.75;
  color: var(--mist);
  overflow-x: hidden;
}

.page-about h1,
.page-about h2,
.page-about h3 {
  font-family: var(--font-display);
  font-weight: 900;
  letter-spacing: -0.02em;
  color: var(--paper);
  margin: 0;
}

.page-about h1 {
  font-size: clamp(30px, 5.2vw, 54px);
  line-height: 1.14;
  margin-top: 12px;
  max-width: 20ch;
}

.page-about h2 {
  font-size: var(--fs-h2);
  line-height: 1.2;
  max-width: 24ch;
}

.page-about h3 {
  font-size: var(--fs-h3);
  line-height: 1.34;
  letter-spacing: -0.01em;
}

.page-about p {
  margin: 0 0 16px;
  max-width: 68ch;
}

.page-about a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(53, 224, 208, 0.34);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

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

.page-about :focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
  border-radius: 4px;
}

/* 面包屑 */
.page-about .crumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding: 22px 0 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--stone);
}

.page-about .crumb a {
  color: var(--stone);
  border-bottom: none;
}

.page-about .crumb a:hover {
  color: var(--lava);
}

.page-about .crumb__sep {
  color: var(--brass);
}

/* 首屏 */
.about-hero {
  display: grid;
  gap: clamp(26px, 4vw, 46px);
  padding: clamp(26px, 5vw, 58px) 0 clamp(34px, 5vw, 68px);
  border-bottom: 1px solid var(--line);
}

.about-hero__text {
  min-width: 0;
}

.about-lead {
  margin-top: 20px;
  font-size: clamp(16px, 1.9vw, 19px);
  color: var(--mist);
  max-width: 56ch;
}

.about-hero .eyebrow {
  font-family: var(--font-mono);
  font-size: var(--fs-note);
  letter-spacing: 0.18em;
  color: var(--moss);
  text-transform: uppercase;
  margin: 0;
}

.about-metrics {
  list-style: none;
  margin: 28px 0 0;
  padding: 20px 0 0;
  border-top: 1px solid var(--line-soft);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px 14px;
}

.about-metric {
  display: flex;
  flex-direction: column;
  gap: 4px;
  position: relative;
  padding-top: 12px;
}

.about-metric::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 26px;
  height: 2px;
  background: var(--lava);
}

.about-metric__n {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(24px, 3.4vw, 34px);
  line-height: 1;
  color: var(--paper);
}

.about-metric__l {
  font-size: 13px;
  color: var(--stone);
  letter-spacing: 0.04em;
}

.about-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: 28px 0 0;
}

.about-hero__fig {
  margin: 0;
  position: relative;
  border-radius: var(--r-lg);
  overflow: hidden;
  border: 1px solid var(--line-brass);
  background: var(--night);
}

.about-hero__fig::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(150deg, rgba(53, 224, 208, 0.16), transparent 52%, rgba(255, 106, 43, 0.14));
}

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

.page-about .media__cap {
  display: block;
  padding: 10px 14px 12px;
  font-size: 12px;
  line-height: 1.6;
  color: var(--stone);
  letter-spacing: 0.04em;
}

/* 通用区块 */
.about-sec {
  padding-top: var(--ab-space);
}

.about-sec__lead {
  margin-top: 14px;
  color: var(--stone);
  max-width: 62ch;
}

.page-about .section-head {
  margin-bottom: clamp(22px, 3vw, 36px);
}

.page-about .section-head .eyebrow {
  font-family: var(--font-mono);
  font-size: var(--fs-note);
  letter-spacing: 0.18em;
  color: var(--moss);
  margin: 0 0 10px;
}

/* 2:1 不对称分栏 */
.about-split {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(22px, 3vw, 40px);
  align-items: start;
}

.about-split--rev .about-split__main {
  order: 2;
}

.about-split--rev .about-cover-fig {
  order: 1;
}

.about-split--tight {
  margin-top: 32px;
}

.about-split__main {
  min-width: 0;
}

.about-note {
  border-left: 2px solid var(--moss);
  padding: 4px 0 4px 18px;
  color: var(--stone);
  font-size: 14px;
  line-height: 1.7;
}

.about-note--cyan {
  border-left-color: var(--cyan);
}

.about-note p {
  margin: 0;
  max-width: 34ch;
}

.page-about .vnote {
  font-family: var(--font-mono);
  font-size: var(--fs-note);
  letter-spacing: 0.18em;
  color: var(--brass);
  margin-bottom: 8px;
}

/* 时间轴 */
.about-tl-fig {
  margin: 0 0 clamp(26px, 4vw, 44px);
  border-radius: var(--r-md);
  overflow: hidden;
  border: 1px solid var(--line);
  background: var(--night);
}

.about-tl-fig img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  opacity: 0.9;
}

.about-tl {
  list-style: none;
  margin: 0;
  padding: 0;
}

.about-tl__item {
  position: relative;
  padding: 0 0 32px 30px;
}

.about-tl__item::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 8px;
  bottom: -4px;
  width: 1px;
  background: var(--line);
}

.about-tl__item:last-child::before {
  display: none;
}

.about-tl__item::after {
  content: "";
  position: absolute;
  left: 0;
  top: 8px;
  width: 13px;
  height: 13px;
  border-radius: 50%;
  background: var(--deep);
  border: 1px solid var(--brass);
  transition: background var(--dur) var(--ease), border-color var(--dur) var(--ease),
    box-shadow var(--dur) var(--ease);
}

.about-tl__item:hover::after {
  background: var(--lava);
  border-color: var(--lava);
  box-shadow: 0 0 0 4px rgba(255, 106, 43, 0.14);
}

.about-tl__item.is-in::after {
  background: var(--cyan);
  border-color: var(--cyan);
  box-shadow: 0 0 0 3px rgba(53, 224, 208, 0.16);
}

.about-tl__mark {
  display: flex;
  align-items: baseline;
  gap: 10px;
  margin-bottom: 6px;
}

.about-tl__year {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--cyan);
}

.about-tl__ver {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--stone);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 1px 8px;
}

.about-tl__body p {
  margin: 8px 0 0;
  color: var(--mist);
  max-width: 58ch;
}

.about-tl__item:nth-child(2n) .about-tl__body p {
  max-width: 48ch;
}

.about-tl__item:nth-child(3n) .about-tl__body p {
  max-width: 64ch;
}

.about-tl__foot {
  margin-top: 12px;
  padding-top: 18px;
  border-top: 1px solid var(--line-soft);
  color: var(--stone);
  font-size: 14px;
}

/* 职能标签 */
.about-units {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}

.about-unit {
  position: relative;
  padding: 18px 16px 16px;
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: var(--night);
  transition: border-color var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.about-unit:hover,
.about-unit:focus-within {
  border-color: var(--lava);
  transform: translateY(-4px);
}

.about-unit__idx {
  display: block;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--brass);
  margin-bottom: 10px;
}

.about-unit__name {
  display: block;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(20px, 2.6vw, 30px);
  line-height: 1.16;
  letter-spacing: -0.02em;
  color: var(--stone);
  transition: color var(--dur) var(--ease);
}

.about-unit:hover .about-unit__name,
.about-unit:focus-within .about-unit__name {
  color: var(--paper);
}

.about-unit__desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.68;
  color: var(--stone);
  max-height: 0;
  opacity: 0;
  overflow: hidden;
  transform: translateY(-4px);
  transition: max-height var(--dur) var(--ease), opacity var(--dur) var(--ease),
    transform var(--dur) var(--ease);
}

.about-unit:hover .about-unit__desc,
.about-unit:focus .about-unit__desc,
.about-unit:focus-within .about-unit__desc {
  max-height: 9em;
  opacity: 1;
  margin-top: 10px;
  transform: none;
}

.about-units__note {
  margin-top: 22px;
  padding-left: 16px;
  border-left: 2px solid var(--brass);
  color: var(--stone);
  font-size: 14px;
}

/* 覆盖范围 */
.about-cover-fig {
  margin: 0;
  border-radius: var(--r-lg);
  overflow: hidden;
  border: 1px solid var(--line);
  background: var(--night);
}

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

.about-sports {
  list-style: none;
  margin: clamp(26px, 4vw, 44px) 0 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.about-sport {
  display: grid;
  grid-template-columns: 44px 1fr;
  gap: 4px 12px;
  padding: 18px 10px;
  border-bottom: 1px solid var(--line-soft);
  scroll-margin-top: 90px;
  transition: background var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.about-sport:hover {
  background: rgba(232, 236, 240, 0.04);
}

.about-sport:target {
  background: linear-gradient(90deg, rgba(53, 224, 208, 0.14), transparent 72%);
  border-bottom-color: var(--cyan);
}

.about-sport__idx {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--brass);
  padding-top: 6px;
}

.about-sport__name {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(19px, 2.2vw, 24px);
  letter-spacing: -0.01em;
  color: var(--paper);
}

.about-sport__desc {
  grid-column: 2;
  margin: 0;
  font-size: 14px;
  line-height: 1.68;
  color: var(--stone);
  max-width: 62ch;
}

/* 用户分布图 */
.about-geo {
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  background: linear-gradient(160deg, rgba(18, 41, 63, 0.9), rgba(11, 27, 43, 0.6));
  padding: 20px 16px 8px;
}

.about-geo__svg {
  display: block;
  width: 100%;
  height: clamp(110px, 16vw, 168px);
  overflow: visible;
}

.about-geo__tick {
  fill: var(--stone);
  opacity: 0.45;
}

.about-geo__tick--hot {
  fill: var(--cyan);
  opacity: 0.85;
}

.about-geo__base {
  stroke: var(--line);
  stroke-width: 1;
}

/* 长期使用 */
.about-trust__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  overflow: hidden;
}

.about-trust__item {
  background: var(--deep);
  padding: 22px 18px;
}

.about-trust__k {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--lava);
  margin-bottom: 8px;
}

.about-trust__item p {
  margin: 0;
  color: var(--mist);
  font-size: 15px;
  max-width: 48ch;
}

.about-trust__foot {
  margin-top: 26px;
  padding-top: 20px;
  border-top: 1px solid var(--line-soft);
  color: var(--stone);
  font-size: 15px;
}

/* 平板及以上 */
@media (min-width: 700px) {
  .about-metrics {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

  .about-sport {
    grid-template-columns: 56px minmax(0, 190px) minmax(0, 1fr);
    align-items: baseline;
    gap: 0 18px;
    padding: 20px 14px;
  }

  .about-sport__idx {
    padding-top: 0;
  }

  .about-sport__desc {
    grid-column: 3;
  }

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

/* 桌面端 */
@media (min-width: 960px) {
  .about-hero {
    grid-template-columns: 1.32fr 1fr;
    align-items: end;
  }

  .about-split {
    grid-template-columns: 1.9fr 1fr;
    gap: clamp(30px, 4vw, 58px);
  }

  .about-split--rev {
    grid-template-columns: 1fr 1.5fr;
  }

  .about-split--rev .about-split__main {
    order: 2;
  }

  .about-split--rev .about-cover-fig {
    order: 1;
  }

  .about-split--tight {
    grid-template-columns: 1.6fr 1fr;
  }

  .about-tl__item {
    display: grid;
    grid-template-columns: 168px minmax(0, 1fr);
    gap: 0 24px;
    padding-left: 34px;
  }

  .about-tl__mark {
    flex-direction: column;
    align-items: flex-start;
    gap: 6px;
    margin-bottom: 0;
    padding-top: 6px;
  }

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

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

@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    transition-duration: 1ms !important;
    animation-duration: 1ms !important;
  }
}