.page-about {
  --ab-line: rgba(169, 180, 207, 0.22);
  --ab-line-strong: rgba(169, 180, 207, 0.46);
  --ab-orange-soft: rgba(255, 106, 26, 0.16);
  --ab-cyan-soft: rgba(20, 224, 200, 0.14);
  --ab-panel: rgba(255, 246, 234, 0.045);
  background: var(--ink);
  color: var(--white);
}

/* ---------- 通用排版 ---------- */
.page-about .ab-h2 {
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(26px, 4.6vw, 48px);
  line-height: 1.14;
  letter-spacing: -0.02em;
  color: var(--white);
  margin: 0 0 0.55em;
  max-width: 24ch;
}

.page-about .ab-sub {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 18px;
  line-height: 1.4;
  color: var(--white);
  margin: 0 0 10px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--ab-line);
}

.page-about .ab-head {
  margin-bottom: clamp(28px, 4.5vw, 56px);
  max-width: 860px;
}

.page-about .ab-head .lede {
  margin-top: 0.2em;
}

.page-about .ab-inline-link {
  color: var(--cyan);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-thickness: 1px;
}

.page-about .ab-inline-link:hover,
.page-about .ab-inline-link:focus-visible {
  color: var(--orange);
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  padding-top: clamp(20px, 3.5vw, 44px);
  padding-bottom: clamp(40px, 7vw, 92px);
}

.page-about .ab-hero__grid {
  row-gap: clamp(30px, 5vw, 56px);
  align-items: start;
}

.page-about .ab-hero h1 {
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(36px, 7.4vw, 92px);
  line-height: 1.02;
  letter-spacing: -0.03em;
  margin: 0.16em 0 0.42em;
  max-width: 16ch;
}

.page-about .ab-hero .lede {
  max-width: 42ch;
  color: var(--silver);
}

.page-about .ab-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(22px, 3vw, 34px);
}

.page-about .ab-hero__side {
  border-left: 1px solid var(--ab-line-strong);
  padding-left: clamp(16px, 2.2vw, 30px);
}

.page-about .ab-hero__caption {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--silver);
  margin: 0 0 20px;
}

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

.page-about .ab-facts li {
  display: flex;
  align-items: baseline;
  gap: clamp(12px, 1.6vw, 20px);
  padding: 14px 0;
  border-bottom: 1px solid var(--ab-line);
}

.page-about .ab-facts li:first-child {
  border-top: 1px solid var(--ab-line);
}

.page-about .ab-facts__num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(28px, 4.4vw, 42px);
  font-weight: 700;
  line-height: 1;
  color: var(--orange);
  min-width: 2.1em;
}

.page-about .ab-facts li:nth-child(2) .ab-facts__num {
  color: var(--cyan);
}

.page-about .ab-facts li:nth-child(3) .ab-facts__num {
  color: var(--gold);
}

.page-about .ab-facts__label {
  font-size: 14px;
  line-height: 1.5;
  color: var(--silver);
}

.page-about .ab-hero__foot {
  margin: 20px 0 0;
  font-size: 13px;
  line-height: 1.7;
  color: var(--silver);
}

/* ---------- 起点 ---------- */
.page-about .ab-origin__figure {
  margin: 0 0 clamp(32px, 5vw, 64px);
}

.page-about .ab-origin__figure img {
  aspect-ratio: 16 / 9;
  object-fit: cover;
}

.page-about .ab-origin__body {
  row-gap: clamp(26px, 4vw, 44px);
}

.page-about .ab-origin__title .eyebrow {
  margin-bottom: 12px;
}

.page-about .ab-origin__note {
  border-top: 2px solid var(--orange);
  padding-top: 16px;
  font-size: 13.5px;
  line-height: 1.75;
  color: var(--silver);
}

.page-about .ab-origin__note p {
  margin: 0;
}

/* ---------- 覆盖版图 ---------- */
.page-about .ab-coverage__body {
  row-gap: clamp(32px, 5vw, 56px);
  align-items: center;
}

.page-about .ab-coverage__viz {
  display: grid;
  justify-items: center;
  gap: 18px;
}

.page-about .ab-rings {
  width: min(100%, 360px);
  height: auto;
}

.page-about .ab-rings__track {
  fill: none;
  stroke: rgba(169, 180, 207, 0.14);
  stroke-width: 1.5;
}

.page-about .ab-rings__ticks {
  fill: none;
  stroke: var(--cyan);
  stroke-width: 9;
  stroke-linecap: round;
  transition: stroke 0.3s var(--ease);
}

.page-about .ab-rings__ticks--b {
  stroke: var(--orange);
  stroke-width: 6;
}

.page-about .ab-rings__ticks--c {
  stroke: rgba(255, 194, 75, 0.75);
  stroke-width: 3;
  stroke-linecap: butt;
}

.page-about .ab-rings__legend {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px 18px;
  margin: 0;
  font-size: 12.5px;
  letter-spacing: 0.04em;
  color: var(--silver);
}

.page-about .ab-rings__key {
  display: inline-block;
  width: 14px;
  height: 4px;
  margin-right: 6px;
  vertical-align: middle;
  border-radius: 2px;
  background: var(--cyan);
}

.page-about .ab-rings__key--b {
  background: var(--orange);
}

.page-about .ab-rings__key--c {
  background: var(--gold);
}

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

.page-about .ab-stat {
  padding: clamp(16px, 2.4vw, 24px) 0;
  border-top: 1px solid var(--ab-line);
}

.page-about .ab-stat:last-child {
  border-bottom: 1px solid var(--ab-line);
}

.page-about .ab-stat__num {
  display: block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(34px, 5.4vw, 58px);
  font-weight: 700;
  line-height: 1;
  color: var(--white);
  letter-spacing: -0.02em;
}

.page-about .ab-stat:nth-child(1) .ab-stat__num {
  color: var(--cyan);
}

.page-about .ab-stat:nth-child(2) .ab-stat__num {
  color: var(--orange);
}

.page-about .ab-stat:nth-child(3) .ab-stat__num {
  color: var(--gold);
}

.page-about .ab-stat__unit {
  font-size: 0.42em;
  margin-left: 6px;
  color: var(--silver);
  letter-spacing: 0.04em;
}

.page-about .ab-stat__title {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 17px;
  margin: 10px 0 6px;
  color: var(--white);
}

.page-about .ab-stat p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--silver);
  max-width: 40ch;
}

/* ---------- 数据流程 ---------- */
.page-about .ab-pipeline__body {
  row-gap: clamp(30px, 4vw, 48px);
  align-items: start;
}

.page-about .ab-steps {
  list-style: none;
  margin: 0;
  padding: 0;
  position: relative;
}

.page-about .ab-steps__item {
  position: relative;
  padding: 22px 0 22px clamp(44px, 6vw, 62px);
  border-top: 1px solid var(--ab-line);
}

.page-about .ab-steps__item:last-child {
  border-bottom: 1px solid var(--ab-line);
}

.page-about .ab-steps__num {
  position: absolute;
  left: 0;
  top: 24px;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--orange);
}

.page-about .ab-steps__title {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 19px;
  margin: 0 0 8px;
  color: var(--white);
}

.page-about .ab-steps__item p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--silver);
  max-width: 40ch;
}

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

.page-about .ab-pipeline__figure img {
  aspect-ratio: 14 / 9;
  object-fit: cover;
}

/* ---------- 时间轴 ---------- */
.page-about .ab-timeline__head {
  margin-bottom: clamp(24px, 3.5vw, 40px);
}

.page-about .ab-rail {
  overflow-x: auto;
  overflow-y: hidden;
  scroll-snap-type: x proximity;
  -webkit-overflow-scrolling: touch;
  padding: 6px var(--gutter) 30px;
  border-top: 2px solid var(--ab-line-strong);
  background: linear-gradient(180deg, rgba(27, 27, 71, 0.5), rgba(11, 19, 48, 0));
}

.page-about .ab-rail:focus-visible {
  outline: 2px solid var(--orange);
  outline-offset: 6px;
}

.page-about .ab-rail__list {
  display: grid;
  grid-auto-flow: column;
  grid-auto-columns: minmax(268px, 330px);
  gap: clamp(20px, 3vw, 46px);
  list-style: none;
  margin: 0;
  padding: 26px 0 4px;
}

.page-about .ab-rail__item {
  position: relative;
  scroll-snap-align: start;
  padding-top: 26px;
}

.page-about .ab-rail__item::before {
  content: "";
  position: absolute;
  top: -8px;
  left: 0;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--orange);
}

.page-about .ab-rail__item:nth-child(2)::before {
  background: var(--cyan);
}

.page-about .ab-rail__item:nth-child(3)::before {
  background: var(--gold);
}

.page-about .ab-rail__epoch {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 12.5px;
  letter-spacing: 0.12em;
  color: var(--silver);
  margin: 0 0 14px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--ab-line);
}

.page-about .ab-rail__title {
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(20px, 2.4vw, 26px);
  line-height: 1.2;
  color: var(--white);
  margin: 0 0 12px;
}

.page-about .ab-rail__text {
  margin: 0 0 16px;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--silver);
}

.page-about .ab-rail__tags {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0;
  padding: 0;
}

/* ---------- 银川 ---------- */
.page-about .ab-city__body {
  row-gap: clamp(30px, 4vw, 48px);
  align-items: center;
}

.page-about .ab-city__text .eyebrow {
  margin-bottom: 12px;
}

.page-about .ab-city__link {
  margin: clamp(20px, 3vw, 30px) 0 0;
  font-size: 14.5px;
}

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

.page-about .ab-city__figure img {
  aspect-ratio: 7 / 4;
  object-fit: cover;
}

/* ---------- 合作伙伴 ---------- */
.page-about .ab-partners {
  background: var(--indigo);
}

.page-about .ab-partners__body {
  row-gap: clamp(26px, 4vw, 44px);
}

.page-about .ab-partners__col p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--silver);
  max-width: 38ch;
}

/* ---------- 三项做法 ---------- */
.page-about .ab-promises__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: clamp(22px, 3vw, 40px);
}

.page-about .ab-promise {
  border-top: 2px solid var(--orange);
  padding-top: 20px;
}

.page-about .ab-promise:nth-child(2) {
  border-top-color: var(--cyan);
}

.page-about .ab-promise:nth-child(3) {
  border-top-color: var(--gold);
}

.page-about .ab-promise__num {
  display: block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 13px;
  letter-spacing: 0.14em;
  color: var(--silver);
  margin-bottom: 12px;
}

.page-about .ab-promise__title {
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(20px, 2.6vw, 26px);
  color: var(--white);
  margin: 0 0 10px;
}

.page-about .ab-promise p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--silver);
  max-width: 34ch;
}

/* ---------- 收尾 ---------- */
.page-about .ab-cta {
  padding-bottom: clamp(56px, 9vw, 120px);
}

.page-about .ab-cta__inner {
  border-top: 1px solid var(--ab-line-strong);
  padding-top: clamp(30px, 4.5vw, 56px);
  max-width: 860px;
}

.page-about .ab-cta .lede {
  color: var(--silver);
  max-width: 52ch;
}

.page-about .ab-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(22px, 3vw, 34px);
}

/* ---------- 响应式 ---------- */
@media (max-width: 699px) {
  .page-about .ab-hero__side {
    border-left: 0;
    border-top: 1px solid var(--ab-line-strong);
    padding-left: 0;
    padding-top: 20px;
  }

  .page-about .ab-rail__list {
    grid-auto-columns: minmax(240px, 80vw);
  }

  .page-about .ab-stats {
    margin-top: 4px;
  }

  .page-about .ab-stat p,
  .page-about .ab-steps__item p,
  .page-about .ab-promise p,
  .page-about .ab-partners__col p {
    max-width: none;
  }
}

@media (min-width: 760px) {
  .page-about .ab-promises__list {
    grid-template-columns: repeat(3, 1fr);
  }

  .page-about .ab-stats {
    grid-template-columns: repeat(2, 1fr);
    column-gap: clamp(20px, 3vw, 40px);
  }

  .page-about .ab-stat:nth-child(2) {
    border-top: 1px solid var(--ab-line);
  }

  .page-about .ab-stat:nth-child(2) + .ab-stat,
  .page-about .ab-stat:nth-child(4) {
    border-bottom: 1px solid var(--ab-line);
  }

  .page-about .ab-stat:last-child {
    border-bottom: 1px solid var(--ab-line);
  }
}

@media (min-width: 1024px) {
  .page-about .ab-hero {
    padding-top: clamp(44px, 6vw, 92px);
  }

  .page-about .ab-hero__side {
    margin-top: 10px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-rings__ticks {
    transition: none;
  }

  .page-about .ab-rail {
    scroll-behavior: auto;
  }
}