.page-about {
  --ab-rail: 92px;
  color: var(--ice);
}

.page-about .ab-wrap {
  padding-block: 20px 64px;
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  padding-block: 8px 44px;
}

.page-about .ab-hero__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px 18px;
  margin-top: 34px;
}

.page-about .ab-hero__num {
  font-size: 54px;
  line-height: .84;
  font-weight: 700;
  letter-spacing: .02em;
  color: var(--slate);
  -webkit-text-stroke: 1.5px rgba(52, 227, 212, .58);
}

.page-about .ab-hero__theme {
  font-size: 12px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--cyan);
}

.page-about .ab-hero__title {
  margin: 22px 0 0;
  max-width: 17em;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: clamp(30px, 7.4vw, 50px);
  line-height: 1.2;
  letter-spacing: .025em;
  color: var(--white);
}

.page-about .ab-hero__lead {
  margin: 20px 0 0;
  max-width: 38em;
  font-size: 16px;
  line-height: 1.9;
  color: var(--ice);
}

/* ---------- 章节骨架 ---------- */
.page-about .ab-sec {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
  padding-block: 48px;
  border-top: 1px solid var(--line-soft);
}

.page-about .ab-sec:first-of-type {
  border-top-color: var(--line);
}

.page-about .ab-sec__no {
  display: inline-block;
  padding: 4px 12px;
  border-radius: var(--r-pill);
  background: var(--slate);
  font-size: 12px;
  letter-spacing: .22em;
  color: var(--cyan);
  text-decoration: none;
  transition: background var(--dur) ease, color var(--dur) ease;
}

.page-about .ab-sec__no:hover,
.page-about .ab-sec__no:focus-visible {
  background: var(--cyan);
  color: var(--ink-deep);
}

.page-about .ab-sec__title {
  margin: 0;
  max-width: 21em;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: clamp(22px, 4.8vw, 32px);
  line-height: 1.3;
  letter-spacing: .03em;
  color: var(--ice);
}

.page-about .ab-sec__lead {
  margin: 16px 0 0;
  max-width: 36em;
  font-size: 15px;
  line-height: 1.9;
  color: var(--ice);
}

.page-about .ab-cols__text p,
.page-about .ab-note {
  margin: 16px 0 0;
  max-width: 38em;
  font-size: 16px;
  line-height: 1.9;
  color: var(--ice);
}

.page-about .ab-cols__text p:first-child {
  margin-top: 0;
}

.page-about .ab-note {
  margin-top: 28px;
  padding-left: 16px;
  border-left: 2px solid var(--mint);
  font-size: 15px;
  color: rgba(230, 241, 248, .88);
}

/* ---------- 图片 ---------- */
.page-about .ab-fig {
  margin: 24px 0 0;
}

.page-about .ab-fig .media__frame {
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  background: var(--panel);
  aspect-ratio: 3 / 2;
}

.page-about .ab-fig .media__img {
  display: block;
  width: 100%;
  height: 100%;
  max-width: 100%;
  object-fit: cover;
}

.page-about .ab-fig .media__caption {
  margin-top: 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.7;
  letter-spacing: .03em;
  color: var(--carbon);
}

.page-about .ab-fig--wide {
  margin-top: 26px;
}

.page-about .ab-fig--wide .media__frame {
  aspect-ratio: 16 / 9;
}

.page-about .ab-fig--banner {
  margin-top: 34px;
}

.page-about .ab-fig--banner .media__frame {
  aspect-ratio: 21 / 9;
}

/* ---------- 三层索引 ---------- */
.page-about .ab-layers {
  display: grid;
  gap: 14px;
  margin: 30px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-layer {
  padding: 18px 20px;
  border: 1px solid var(--line-soft);
  border-radius: var(--r-md);
  background: var(--panel);
}

.page-about .ab-layer__key {
  display: block;
  font-size: 13px;
  letter-spacing: .2em;
  color: var(--cyan);
}

.page-about .ab-layer__txt {
  margin: 10px 0 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--ice);
}

/* ---------- 团队 ---------- */
.page-about .ab-team {
  display: grid;
  gap: 14px;
  margin-top: 28px;
}

.page-about .ab-role {
  border: 1px solid var(--line-soft);
  border-radius: var(--r-md);
  background: var(--panel);
  transition: border-color var(--dur) ease, background var(--dur) ease;
}

.page-about .ab-role[open] {
  border-color: var(--line);
  background: linear-gradient(180deg, rgba(27, 59, 73, .55), rgba(19, 44, 66, .95));
}

.page-about .ab-role__head {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 17px 20px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .ab-role__name {
  flex: 1 1 auto;
  min-width: 0;
  font-size: 17px;
  font-weight: 500;
  line-height: 1.5;
  color: var(--white);
}

.page-about .ab-role__count {
  flex: 0 0 auto;
  padding: 3px 10px;
  border-radius: var(--r-pill);
  background: var(--slate);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--cyan);
}

.page-about .ab-role__head::after {
  content: "+";
  flex: 0 0 auto;
  width: 22px;
  text-align: center;
  font-family: var(--font-mono);
  font-size: 18px;
  line-height: 1;
  color: var(--orange);
  transition: transform var(--dur) ease;
}

.page-about .ab-role[open] .ab-role__head::after {
  content: "\2212";
}

.page-about .ab-role__body {
  padding: 0 20px 20px;
}

.page-about .ab-role__body p {
  margin: 0;
  max-width: 34em;
  font-size: 15px;
  line-height: 1.85;
  color: var(--ice);
}

/* ---------- 时间轴 ---------- */
.page-about .ab-tl {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
  margin-top: 30px;
}

.page-about .ab-tl::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 8px;
  bottom: 20px;
  width: 2px;
  border-radius: var(--r-pill);
  background: linear-gradient(180deg, var(--cyan), rgba(52, 227, 212, .06));
}

.page-about .ab-tl__node {
  position: relative;
  padding: 0 0 26px 32px;
  outline: none;
}

.page-about .ab-tl__dot {
  position: absolute;
  left: 0;
  top: 3px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--ink);
  border: 2px solid var(--carbon);
  transition: border-color var(--dur) ease, box-shadow var(--dur) ease;
}

.page-about .ab-tl__label {
  display: block;
  font-size: 19px;
  font-weight: 700;
  letter-spacing: .04em;
  color: var(--cyan);
}

.page-about .ab-tl__name {
  display: block;
  margin-top: 4px;
  font-size: 15px;
  color: var(--white);
}

.page-about .ab-tl__tip {
  display: block;
  margin-top: 8px;
  max-width: 22em;
  font-size: 13px;
  line-height: 1.75;
  color: var(--carbon);
  transition: color var(--dur) ease;
}

.page-about .ab-tl__node:hover .ab-tl__dot,
.page-about .ab-tl__node:focus-visible .ab-tl__dot {
  border-color: var(--cyan);
  box-shadow: 0 0 0 5px rgba(52, 227, 212, .14);
}

.page-about .ab-tl__node:hover .ab-tl__tip,
.page-about .ab-tl__node:focus-visible .ab-tl__tip {
  color: var(--ice);
}

.page-about .ab-tl__node--now .ab-tl__dot {
  background: var(--cyan);
  border-color: var(--cyan);
  box-shadow: 0 0 0 5px rgba(52, 227, 212, .18);
}

.page-about .ab-tl__node--now .ab-tl__label {
  color: var(--orange);
}

/* ---------- 合作 ---------- */
.page-about .ab-partner {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
  margin-top: 28px;
}

.page-about .ab-partner__col {
  padding: 22px 20px;
  border-radius: var(--r-lg);
  border: 1px solid var(--line-soft);
  background: rgba(19, 44, 66, .72);
}

.page-about .ab-partner__col:last-child {
  background: rgba(30, 110, 106, .18);
  border-color: rgba(30, 110, 106, .45);
}

.page-about .ab-partner__title {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 19px;
  letter-spacing: .04em;
  color: var(--white);
}

.page-about .ab-partner__col p {
  margin: 12px 0 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--ice);
}

.page-about .ab-local {
  margin-top: 26px;
  padding: 24px 22px;
  border-radius: var(--r-lg);
  border: 1px dashed var(--line);
  background: var(--ink-deep);
}

.page-about .ab-local__key {
  margin: 0;
  font-size: 13px;
  letter-spacing: .16em;
  color: var(--orange);
}

.page-about .ab-local__note {
  margin: 14px 0 0;
  max-width: 40em;
  font-size: 15px;
  line-height: 1.9;
  color: var(--ice);
}

.page-about .ab-local__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 20px;
}

/* ---------- 结尾条 ---------- */
.page-about .ab-cta {
  margin-top: 40px;
  padding: 32px 22px;
  border-radius: var(--r-lg);
  border: 1px solid var(--line);
  background: linear-gradient(135deg, rgba(27, 59, 73, .7), rgba(6, 17, 28, .95) 62%);
}

.page-about .ab-cta__eyebrow {
  margin: 0;
  font-size: 12px;
  letter-spacing: .2em;
  color: var(--cyan);
}

.page-about .ab-cta__title {
  margin: 14px 0 0;
  max-width: 20em;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: clamp(21px, 4.6vw, 28px);
  line-height: 1.32;
  letter-spacing: .03em;
  color: var(--white);
}

.page-about .ab-cta__note {
  margin: 14px 0 0;
  max-width: 40em;
  font-size: 15px;
  line-height: 1.9;
  color: var(--ice);
}

.page-about .ab-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 22px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 760px) {
  .page-about .ab-hero__num {
    font-size: 76px;
  }

  .page-about .ab-cols {
    display: grid;
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: 40px;
    align-items: start;
    margin-top: 26px;
  }

  .page-about .ab-cols .ab-fig {
    margin-top: 6px;
  }

  .page-about .ab-layer {
    display: grid;
    grid-template-columns: 84px minmax(0, 1fr);
    gap: 8px 22px;
    align-items: baseline;
    padding: 20px 24px;
  }

  .page-about .ab-layer__txt {
    margin-top: 0;
  }

  .page-about .ab-layer:nth-child(2) {
    margin-left: 24px;
    margin-right: 24px;
  }

  .page-about .ab-layer:nth-child(3) {
    margin-left: 48px;
  }

  .page-about .ab-partner {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 24px;
  }

  .page-about .ab-partner__col:last-child {
    margin-top: 36px;
  }

  .page-about .ab-cta {
    padding: 40px 36px;
  }
}

@media (min-width: 900px) {
  .page-about .ab-wrap {
    padding-block: 32px 96px;
  }

  .page-about .ab-hero {
    padding-block: 16px 64px;
  }

  .page-about .ab-sec {
    grid-template-columns: var(--ab-rail) minmax(0, 1fr);
    gap: 32px;
    padding-block: 84px;
  }

  .page-about .ab-sec__no {
    position: sticky;
    top: 122px;
    padding: 0;
    border-radius: 0;
    background: transparent;
    font-size: 26px;
    font-weight: 700;
    letter-spacing: .04em;
    color: var(--slate);
  }

  .page-about .ab-sec__no:hover,
  .page-about .ab-sec__no:focus-visible {
    background: transparent;
    color: var(--cyan);
  }

  .page-about .ab-team {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    align-items: start;
    gap: 20px;
  }

  .page-about .ab-role:nth-child(2) {
    margin-top: 34px;
  }

  .page-about .ab-role:nth-child(3) {
    margin-top: 68px;
  }

  .page-about .ab-tl {
    grid-template-columns: repeat(5, minmax(0, 1fr));
    gap: 0 18px;
    margin-top: 40px;
  }

  .page-about .ab-tl::before {
    left: 0;
    right: 0;
    top: 8px;
    bottom: auto;
    width: auto;
    height: 2px;
    background: linear-gradient(90deg, var(--cyan), rgba(52, 227, 212, .06));
  }

  .page-about .ab-tl__node {
    padding: 34px 0 0;
  }

  .page-about .ab-tl__dot {
    left: 0;
    top: 0;
  }

  .page-about .ab-tl__tip {
    max-width: none;
  }

  .page-about .ab-fig--banner {
    margin-top: 48px;
  }
}

@media (min-width: 1100px) {
  .page-about .ab-hero__num {
    font-size: 92px;
  }

  .page-about .ab-cols {
    gap: 56px;
  }
}