.page-about {
  background-color: var(--sand);
  color: var(--char);
  font-family: var(--font-sans);
}

.page-about .crumb {
  padding: 18px 0 0;
  font-size: 13px;
  letter-spacing: .02em;
  color: var(--stone);
}

.page-about .crumb a {
  color: var(--gold-deep);
  text-decoration: none;
}

.page-about .crumb a:hover {
  text-decoration: underline;
}

/* ---------- 首屏 ---------- */

.page-about .ab-hero {
  position: relative;
  overflow: hidden;
  margin-top: 14px;
  padding: 34px 0 44px;
  background-color: var(--ind-night);
  background-image:
    radial-gradient(circle at 84% 12%, rgba(232, 163, 61, .16), transparent 58%),
    radial-gradient(circle at 6% 92%, rgba(42, 75, 133, .55), transparent 60%);
  color: var(--sand);
}

.page-about .ab-hero__grid {
  display: grid;
  gap: 30px;
}

.page-about .ab-hero__lead .eyebrow {
  color: var(--gold-2);
}

.page-about .ab-hero h1 {
  margin: 12px 0 16px;
  font-size: clamp(30px, 8vw, 46px);
  line-height: 1.06;
  font-weight: 800;
  letter-spacing: -.015em;
  color: #fff;
}

.page-about .ab-hero .page-lede {
  margin: 0;
  max-width: 60ch;
  font-size: 16px;
  line-height: 1.9;
  color: rgba(245, 239, 227, .84);
}

.page-about .ab-hero__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 26px 0 0;
  padding: 1px;
  list-style: none;
  background-color: var(--ind-soft);
}

.page-about .ab-hero__stat {
  display: block;
  padding: 12px 14px;
  background-color: var(--ind-night);
}

.page-about .ab-hero__stat .stat__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 24px;
  letter-spacing: .04em;
  color: var(--gold);
}

.page-about .ab-hero__stat .stat__cap {
  display: block;
  margin-top: 4px;
  font-size: 12px;
  letter-spacing: .06em;
  color: rgba(245, 239, 227, .68);
}

.page-about .ab-hero__figure {
  margin: 0;
  transform: rotate(-1.2deg);
}

.page-about .ab-hero__figure .plate__cap {
  margin-top: 10px;
  font-size: 12px;
  letter-spacing: .04em;
  color: rgba(245, 239, 227, .6);
}

/* ---------- 主体骨架 ---------- */

.page-about .ab-body {
  padding: 44px 0 72px;
}

.page-about .ab-rail {
  margin-bottom: 32px;
}

.page-about .ab-rail__title {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--stone);
}

.page-about .ab-rail .rail__list {
  display: flex;
  gap: 14px;
  margin: 0;
  padding: 0 0 10px;
  list-style: none;
  overflow-x: auto;
  border-bottom: 1px solid var(--paper);
  -webkit-overflow-scrolling: touch;
}

.page-about .ab-rail .rail__link {
  display: block;
  white-space: nowrap;
  padding: 3px 0;
  font-size: 13px;
  letter-spacing: .03em;
  color: var(--stone);
  text-decoration: none;
  border-bottom: 2px solid transparent;
}

.page-about .ab-rail .rail__link:hover,
.page-about .ab-rail .rail__link[aria-current="true"] {
  color: var(--char);
  border-bottom-color: var(--gold);
}

.page-about .ab-sec {
  margin-bottom: 64px;
}

.page-about .ab-sec:last-child {
  margin-bottom: 0;
}

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

.page-about .section-head .eyebrow {
  color: var(--gold-deep);
}

.page-about .section-head h2 {
  margin: 8px 0 12px;
  font-size: clamp(23px, 5.4vw, 33px);
  line-height: 1.14;
  font-weight: 800;
  letter-spacing: -.01em;
}

.page-about .ab-sec__lede {
  margin: 0;
  max-width: 68ch;
  font-size: 16px;
  line-height: 1.9;
  color: var(--stone);
}

/* ---------- 时间轴 ---------- */

.page-about .ab-track__plate {
  margin: 0 0 22px;
  transform: rotate(.5deg);
}

.page-about .ab-track {
  display: grid;
  grid-auto-flow: column;
  grid-auto-columns: minmax(178px, 1fr);
  gap: 10px;
  margin: 0;
  padding: 0 0 12px;
  list-style: none;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
}

.page-about .ab-track__node {
  position: relative;
  scroll-snap-align: start;
  padding: 26px 14px 16px;
  background-color: var(--sand);
  border: 1px solid var(--paper);
  border-top: 3px solid var(--ind-soft);
  box-shadow: 4px 4px 0 rgba(227, 216, 196, .75);
}

.page-about .ab-track__node--now {
  border-top-color: var(--signal);
  background-color: #fff;
}

.page-about .ab-track__year {
  position: absolute;
  top: 8px;
  left: 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--gold-deep);
}

.page-about .ab-track__node--now .ab-track__year {
  color: var(--signal);
}

.page-about .ab-track__title {
  margin: 0 0 8px;
  font-size: 15px;
  line-height: 1.35;
  font-weight: 700;
}

.page-about .ab-track__note {
  margin: 0;
  font-size: 13px;
  line-height: 1.75;
  color: var(--stone);
}

.page-about .ab-track__more {
  margin: 10px 0 0;
  padding-top: 10px;
  border-top: 1px dashed var(--paper);
  font-size: 12px;
  line-height: 1.7;
  color: var(--clay);
}

/* ---------- 五项服务 ---------- */

.page-about .ab-svc {
  display: grid;
  gap: 14px;
}

.page-about .ab-svc__item {
  padding: 20px 18px 22px;
}

.page-about .ab-svc__item h3 {
  margin: 12px 0 8px;
  font-size: 17px;
  line-height: 1.35;
  font-weight: 700;
}

.page-about .ab-svc__item p {
  margin: 0;
  font-size: 14px;
  line-height: 1.85;
  color: var(--stone);
}

.page-about .ab-svc__foot {
  margin: 20px 0 0;
  font-size: 14px;
  color: var(--stone);
}

.page-about .ab-svc__foot a {
  color: var(--gold-deep);
  font-weight: 700;
  text-decoration: none;
  border-bottom: 1px solid var(--gold);
}

.page-about .ab-svc__foot a:hover {
  color: var(--char);
}

/* ---------- 引言卡 ---------- */

.page-about .ab-pull {
  margin: 0 0 64px;
  padding: 24px 22px;
  background-color: var(--paper);
  border-left: 4px solid var(--signal);
  box-shadow: 6px 6px 0 rgba(27, 36, 48, .08);
  transform: rotate(-.4deg);
}

.page-about .ab-pull p {
  margin: 0;
  font-size: 18px;
  line-height: 1.75;
  font-weight: 600;
  color: var(--char);
}

/* ---------- 团队 ---------- */

.page-about .ab-team {
  display: grid;
  gap: 26px;
}

.page-about .ab-team__plate {
  margin: 0;
}

.page-about .ab-team__text p {
  margin: 0 0 16px;
  font-size: 16px;
  line-height: 1.9;
  color: var(--char);
}

.page-about .ab-chart {
  margin-top: 26px;
  padding: 18px 16px;
  background-color: var(--ind-night);
  border-left: 3px solid var(--gold);
}

.page-about .ab-chart__title {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--gold-2);
}

.page-about .ab-chart__rows {
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-chart__row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 72px;
  grid-template-areas:
    "name val"
    "bar  bar";
  align-items: center;
  gap: 4px 10px;
  padding: 9px 0;
  border-bottom: 1px solid rgba(42, 75, 133, .6);
}

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

.page-about .ab-chart__name {
  grid-area: name;
  font-size: 13px;
  letter-spacing: .02em;
  color: rgba(245, 239, 227, .82);
}

.page-about .ab-chart__val {
  grid-area: val;
  text-align: right;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--sand);
}

.page-about .ab-chart__bar {
  grid-area: bar;
  display: block;
  width: 100%;
  height: 8px;
  background-color: rgba(42, 75, 133, .4);
}

.page-about .ab-chart__rect--moss {
  fill: var(--moss);
}

.page-about .ab-chart__rect--clay {
  fill: var(--clay);
}

.page-about .ab-chart__legend {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin: 14px 0 0;
  font-size: 12px;
  letter-spacing: .04em;
  color: rgba(245, 239, 227, .7);
}

.page-about .ab-chart__key {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.page-about .ab-chart__key::before {
  content: "";
  width: 14px;
  height: 8px;
  display: inline-block;
}

.page-about .ab-chart__key--moss::before {
  background-color: var(--moss);
}

.page-about .ab-chart__key--clay::before {
  background-color: var(--clay);
}

/* ---------- 更新与维护 ---------- */

.page-about .ab-upkeep {
  display: grid;
  gap: 0;
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: 2px solid var(--ind-soft);
}

.page-about .ab-upkeep__item {
  position: relative;
  padding: 20px 0 20px 52px;
  border-bottom: 1px solid var(--paper);
}

.page-about .ab-upkeep__idx {
  position: absolute;
  left: 0;
  top: 20px;
  font-family: var(--font-mono);
  font-size: 15px;
  letter-spacing: .08em;
  color: var(--gold-deep);
}

.page-about .ab-upkeep__item h3 {
  margin: 0 0 8px;
  font-size: 16px;
  line-height: 1.4;
  font-weight: 700;
}

.page-about .ab-upkeep__item p {
  margin: 0;
  max-width: 64ch;
  font-size: 14px;
  line-height: 1.85;
  color: var(--stone);
}

/* ---------- 合作生态 ---------- */

.page-about .ab-partners {
  display: grid;
  gap: 14px;
  margin: 0 0 26px;
  padding: 0;
  list-style: none;
}

.page-about .ab-partners__card {
  padding: 18px 18px 6px;
  background-color: var(--sand);
  border: 1px solid var(--paper);
  box-shadow: 5px 5px 0 rgba(227, 216, 196, .8);
}

.page-about .ab-partners__summary {
  display: block;
  cursor: pointer;
  list-style: none;
}

.page-about .ab-partners__summary::-webkit-details-marker {
  display: none;
}

.page-about .ab-partners__summary h3 {
  margin: 12px 0 6px;
  font-size: 17px;
  line-height: 1.35;
  font-weight: 700;
}

.page-about .ab-partners__hint {
  display: inline-block;
  padding-bottom: 6px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--gold-deep);
  border-bottom: 1px solid var(--gold);
}

.page-about .ab-partners__card p {
  margin: 0 0 16px;
  max-width: 64ch;
  font-size: 14px;
  line-height: 1.85;
  color: var(--stone);
}

.page-about .ab-band {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding: 16px;
  background-color: var(--ind-mid);
}

.page-about .ab-band .band__item {
  padding: 7px 12px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--sand);
  border: 1px solid rgba(232, 163, 61, .5);
}

/* ---------- 进一步了解 ---------- */

.page-about .ab-next__list {
  display: grid;
  gap: 14px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-next__card {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  padding: 22px 20px;
  background-color: #fff;
  border: 1px solid var(--paper);
  border-top: 3px solid var(--gold);
}

.page-about .ab-next__card h3 {
  margin: 0 0 10px;
  font-size: 17px;
  font-weight: 700;
}

.page-about .ab-next__card p {
  margin: 0 0 18px;
  font-size: 14px;
  line-height: 1.85;
  color: var(--stone);
}

.page-about .ab-next__card .btn {
  margin-top: auto;
}

/* ---------- 平板与桌面 ---------- */

@media (min-width: 640px) {
  .page-about .ab-hero__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

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

@media (min-width: 900px) {
  .page-about .ab-hero {
    padding: 48px 0 62px;
  }

  .page-about .ab-hero__grid {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr);
    align-items: end;
    gap: 52px;
  }

  .page-about .ab-team {
    grid-template-columns: minmax(0, .85fr) minmax(0, 1.15fr);
    gap: 36px;
    align-items: start;
  }

  .page-about .ab-track {
    grid-auto-flow: row;
    grid-template-columns: repeat(7, minmax(0, 1fr));
    overflow: visible;
    padding-bottom: 0;
  }
}

@media (min-width: 1024px) {
  .page-about .ab-body {
    display: grid;
    grid-template-columns: 186px minmax(0, 1fr);
    gap: 52px;
    align-items: start;
    padding-top: 56px;
  }

  .page-about .ab-rail {
    position: sticky;
    top: 96px;
    margin-bottom: 0;
  }

  .page-about .ab-rail .rail__list {
    display: block;
    overflow: visible;
    padding-bottom: 0;
    border-bottom: 0;
  }

  .page-about .ab-rail .rail__list li {
    margin-bottom: 4px;
  }

  .page-about .ab-rail .rail__link {
    display: block;
    padding: 7px 0 7px 12px;
    border-bottom: 0;
    border-left: 2px solid var(--paper);
  }

  .page-about .ab-rail .rail__link:hover,
  .page-about .ab-rail .rail__link[aria-current="true"] {
    border-left-color: var(--gold);
    border-bottom-color: transparent;
    background-color: rgba(227, 216, 196, .35);
  }

  .page-about .ab-svc {
    grid-template-columns: repeat(6, minmax(0, 1fr));
  }

  .page-about .ab-svc__item {
    grid-column: span 2;
  }

  .page-about .ab-svc__item--lead {
    grid-column: span 3;
  }
}

@media (min-width: 1240px) {
  .page-about .ab-pull {
    margin-left: -60px;
    margin-right: 60px;
  }
}

@media (hover: none) {
  .page-about .ab-partners__card[open] .ab-partners__hint {
    color: var(--stone);
    border-bottom-color: transparent;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-hero__figure,
  .page-about .ab-track__plate,
  .page-about .ab-pull {
    transform: none;
  }
}