.page-about {
  --ab-grid-line: rgba(167, 180, 194, 0.10);
  --ab-clay-soft: rgba(182, 106, 75, 0.16);
  background: var(--arena-900);
  color: var(--on-dark);
  overflow-x: hidden;
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  position: relative;
  padding-block: clamp(20px, 3.4vw, 36px) clamp(40px, 6vw, 76px);
  background:
    radial-gradient(120% 90% at 88% 0%, rgba(53, 242, 208, 0.10), transparent 58%),
    linear-gradient(180deg, var(--command-800), var(--arena-900) 78%);
  overflow: hidden;
}

.page-about .ab-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--ab-grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--ab-grid-line) 1px, transparent 1px);
  background-size: 72px 72px;
  -webkit-mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.85), transparent 82%);
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.85), transparent 82%);
  pointer-events: none;
}

.page-about .ab-hero__inner {
  position: relative;
  z-index: 1;
}

.page-about .ab-hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 4vw, 52px);
  margin-top: clamp(22px, 3.4vw, 40px);
}

.page-about .ab-hero__lead h1 {
  margin: 14px 0 0;
  font-family: var(--font-display);
  font-size: clamp(32px, 6.6vw, 62px);
  font-weight: 900;
  line-height: 1.06;
  letter-spacing: -0.02em;
  color: var(--paper-50);
  max-width: 22ch;
}

.page-about .ab-hero__mark {
  display: block;
  margin-top: 10px;
  color: var(--cyan-400);
}

.page-about .ab-hero__desc {
  margin: 20px 0 0;
  max-width: 60ch;
  font-size: clamp(15px, 1.7vw, 17px);
  line-height: 1.8;
  color: var(--on-dark-dim);
}

.page-about .ab-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

.page-about .ab-quick {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 12px 14px;
  align-items: start;
  margin-top: clamp(24px, 3.6vw, 38px);
  padding: 16px 18px;
  border: 1px solid var(--line-strong);
  border-left: 3px solid var(--orange-500);
  background: rgba(18, 44, 71, 0.62);
}

.page-about .ab-quick__star {
  font-size: 18px;
  line-height: 1.4;
  color: var(--orange-500);
}

.page-about .ab-quick__title {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--on-dark);
}

.page-about .ab-quick__text {
  margin: 6px 0 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--on-dark-muted);
}

.page-about .ab-quick__link {
  grid-column: 2;
  justify-self: start;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--cyan-400);
  text-decoration: none;
  border-bottom: 1px solid rgba(53, 242, 208, 0.4);
  padding-bottom: 2px;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .ab-quick__link:hover,
.page-about .ab-quick__link:focus-visible {
  color: var(--orange-500);
  border-color: var(--orange-500);
}

/* 数据栏 */
.page-about .ab-hero__rail {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line-strong);
  border: 1px solid var(--line-strong);
  align-self: start;
}

.page-about .ab-stat {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 16px 14px;
  background: var(--command-800);
}

.page-about .ab-stat__num {
  font-family: var(--font-mono);
  font-size: clamp(21px, 2.6vw, 28px);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.01em;
  color: var(--cyan-400);
  font-variant-numeric: tabular-nums;
}

.page-about .ab-stat:nth-child(even) .ab-stat__num {
  color: var(--orange-500);
}

.page-about .ab-stat__label {
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--on-dark-muted);
}

/* 章节索引条 */
.page-about .ab-index {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 10px;
  align-items: center;
  margin-top: clamp(30px, 4vw, 48px);
  padding-top: 18px;
  border-top: 1px solid var(--line-soft);
}

.page-about .ab-index__cap {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--on-dark-muted);
  margin-right: 6px;
}

.page-about .ab-index__item {
  display: inline-flex;
  align-items: baseline;
  gap: 6px;
  padding: 6px 11px;
  font-size: 13px;
  color: var(--on-dark-dim);
  text-decoration: none;
  border: 1px solid var(--line-soft);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.page-about .ab-index__item:hover,
.page-about .ab-index__item:focus-visible {
  color: var(--arena-900);
  background: var(--cyan-400);
  border-color: var(--cyan-400);
}

.page-about .ab-index__n {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--orange-500);
}

.page-about .ab-index__item:hover .ab-index__n,
.page-about .ab-index__item:focus-visible .ab-index__n {
  color: var(--arena-900);
}

/* ---------- 章节骨架 ---------- */
.page-about .ab-sec {
  position: relative;
  padding-block: clamp(46px, 7vw, 92px);
  border-top: 1px solid var(--line-soft);
  scroll-margin-top: 92px;
}

.page-about .ab-sec--dark {
  background: var(--arena-900);
  color: var(--on-dark);
}

.page-about .ab-sec--paper {
  background: var(--cream-100);
  color: var(--on-light);
  border-top-color: var(--line-light);
}

.page-about .ab-sec__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(18px, 2.6vw, 34px);
}

.page-about .ab-sec__aside {
  display: flex;
  align-items: baseline;
  gap: 12px;
}

.page-about .ab-sec__num {
  font-family: var(--font-mono);
  font-size: clamp(38px, 6vw, 68px);
  font-weight: 200;
  line-height: 0.86;
  letter-spacing: -0.04em;
  color: var(--rock-600);
}

.page-about .ab-sec--dark .ab-sec__num {
  color: rgba(167, 180, 194, 0.34);
}

.page-about .ab-sec__label {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--on-light-muted);
}

.page-about .ab-sec--dark .ab-sec__label {
  color: var(--on-dark-muted);
}

.page-about .ab-sec__main > h2 {
  margin: 0 0 18px;
  font-family: var(--font-display);
  font-size: clamp(24px, 3.5vw, 40px);
  font-weight: 800;
  line-height: 1.18;
  letter-spacing: -0.02em;
  max-width: 24ch;
}

.page-about .ab-sec__main > p {
  margin: 0 0 16px;
  font-size: 16px;
  line-height: 1.78;
  max-width: 68ch;
  color: var(--on-light-muted);
}

.page-about .ab-sec--dark .ab-sec__main > p {
  color: var(--on-dark-dim);
}

.page-about .ab-lead {
  font-size: clamp(16px, 1.9vw, 19px) !important;
  line-height: 1.75 !important;
  color: var(--on-light) !important;
}

.page-about .ab-sec--dark .ab-lead {
  color: var(--on-dark) !important;
}

.page-about .ab-note {
  margin-top: 20px;
  padding-left: 14px;
  border-left: 2px solid var(--clay-500);
  font-size: 14px;
  line-height: 1.75;
  color: var(--on-light-muted);
  max-width: 62ch;
}

.page-about .ab-sec--dark .ab-note {
  color: var(--on-dark-muted);
}

/* 三段规模说明 */
.page-about .ab-scale {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin: 24px 0 6px;
  background: var(--line-light);
  border: 1px solid var(--line-light);
}

.page-about .ab-scale__item {
  padding: 16px 16px 18px;
  background: var(--paper-50);
}

.page-about .ab-scale__k {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--clay-500);
}

.page-about .ab-scale__v {
  margin: 0;
  font-size: 14px;
  line-height: 1.72;
  color: var(--on-light-muted);
}

/* ---------- 图片区 ---------- */
.page-about .ab-figure {
  margin: 26px 0 30px;
}

.page-about .ab-figure__cap {
  margin-top: 10px;
  font-size: 12px;
  line-height: 1.65;
  letter-spacing: 0.02em;
  color: var(--on-light-muted);
}

.page-about .ab-sec--dark .ab-figure__cap {
  color: var(--on-dark-muted);
}

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

/* ---------- 时间线 ---------- */
.page-about .ab-tl {
  list-style: none;
  margin: 8px 0 0;
  padding: 0;
}

.page-about .ab-tl__item {
  position: relative;
  padding-left: 30px;
}

.page-about .ab-tl__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 17px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--clay-500);
  box-shadow: 0 0 0 4px var(--ab-clay-soft);
}

.page-about .ab-tl__item::after {
  content: "";
  position: absolute;
  left: 5px;
  top: 32px;
  bottom: 6px;
  width: 1px;
  background: var(--line-strong);
}

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

.page-about .ab-tl__d {
  border-bottom: 1px solid var(--line-soft);
}

.page-about .ab-tl__sum {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 9px 0;
  cursor: pointer;
  list-style: none;
}

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

.page-about .ab-tl__year {
  flex: none;
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--orange-500);
  font-variant-numeric: tabular-nums;
}

.page-about .ab-tl__title {
  font-family: var(--font-display);
  font-size: clamp(16px, 2vw, 19px);
  font-weight: 700;
  line-height: 1.4;
  color: var(--paper-50);
}

.page-about .ab-tl__sum:hover .ab-tl__title,
.page-about .ab-tl__d[open] .ab-tl__title {
  color: var(--cyan-400);
}

.page-about .ab-tl__body {
  margin: 0 0 18px;
  padding-left: 2px;
  font-size: 14px;
  line-height: 1.82;
  max-width: 64ch;
  color: var(--on-dark-dim);
}

/* ---------- 团队 ---------- */
.page-about .ab-team {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
  margin: 24px 0 4px;
}

.page-about .ab-team__card {
  padding: 20px 20px 22px;
  background: var(--paper-50);
  border: 1px solid var(--line-light);
  border-top: 3px solid var(--moss-500);
  transition: transform var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .ab-team__card:nth-child(2n) {
  border-top-color: var(--cyan-400);
}

.page-about .ab-team__card:nth-child(3n) {
  border-top-color: var(--clay-500);
}

.page-about .ab-team__card:nth-child(4n) {
  border-top-color: var(--orange-500);
}

.page-about .ab-team__card:hover {
  transform: translateY(-3px);
}

.page-about .ab-team__h {
  margin: 12px 0 8px;
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 800;
  letter-spacing: -0.01em;
  line-height: 1.35;
  color: var(--on-light);
}

.page-about .ab-team__p {
  margin: 0;
  font-size: 14px;
  line-height: 1.76;
  color: var(--on-light-muted);
}

/* ---------- 生态 ---------- */
.page-about .ab-eco {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 3vw, 36px);
  margin-top: 22px;
  align-items: center;
}

.page-about .ab-eco__svg {
  border: 1px solid var(--line-strong);
  background: linear-gradient(160deg, rgba(18, 44, 71, 0.9), rgba(11, 30, 51, 0.9));
  padding: 10px;
}

.page-about .ab-eco__svg svg {
  display: block;
  width: 100%;
  height: auto;
}

.page-about .ab-net__lines line {
  stroke: var(--line-strong);
  stroke-width: 1;
}

.page-about .ab-net__core {
  fill: var(--orange-500);
}

.page-about .ab-net__node {
  fill: var(--moss-500);
  stroke: var(--arena-900);
  stroke-width: 3;
}

.page-about .ab-net__labels text {
  fill: var(--on-dark-muted);
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.06em;
}

.page-about .ab-net__labels text:first-child {
  fill: var(--arena-900);
  font-weight: 700;
  font-size: 12px;
}

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

.page-about .ab-eco__list li {
  position: relative;
  padding-left: 16px;
  font-size: 14px;
  line-height: 1.78;
  color: var(--on-dark-dim);
}

.page-about .ab-eco__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  width: 7px;
  height: 7px;
  background: var(--cyan-400);
  transform: rotate(45deg);
}

.page-about .ab-eco__list strong {
  color: var(--paper-50);
  font-weight: 700;
}

.page-about .ab-eco__note {
  margin: 20px 0 0;
  padding-top: 16px;
  border-top: 1px solid var(--line-soft);
  font-size: 13px;
  line-height: 1.78;
  color: var(--on-dark-muted);
}

/* ---------- 工作方法 ---------- */
.page-about .ab-values {
  display: grid;
  gap: 10px;
  margin-top: 22px;
}

.page-about .ab-value {
  border: 1px solid var(--line-light);
  border-left: 3px solid var(--rock-600);
  background: var(--paper-50);
  transition: border-color var(--dur) var(--ease);
}

.page-about .ab-value[open] {
  border-left-color: var(--clay-500);
}

.page-about .ab-value__sum {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 15px 16px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .ab-value__idx {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--clay-500);
}

.page-about .ab-value__name {
  font-family: var(--font-display);
  font-size: clamp(17px, 2.2vw, 21px);
  font-weight: 800;
  color: var(--on-light);
}

.page-about .ab-value__hint {
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--on-light-muted);
  white-space: nowrap;
}

.page-about .ab-value__body {
  margin: 0;
  padding: 0 16px 18px 42px;
  font-size: 14px;
  line-height: 1.8;
  color: var(--on-light-muted);
}

/* ---------- 参与 ---------- */
.page-about .ab-sec--join {
  border-top-color: var(--line-strong);
}

.page-about .ab-join {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
  margin-top: 24px;
}

.page-about .ab-join__card {
  display: grid;
  gap: 8px;
  padding: 22px 20px;
  text-decoration: none;
  background: rgba(18, 44, 71, 0.72);
  border: 1px solid var(--line-strong);
  transition: background-color var(--dur) var(--ease), border-color var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.page-about .ab-join__card:hover,
.page-about .ab-join__card:focus-visible {
  background: rgba(53, 242, 208, 0.08);
  border-color: var(--cyan-400);
  transform: translateY(-3px);
}

.page-about .ab-join__k {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--orange-500);
}

.page-about .ab-join__t {
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 800;
  line-height: 1.45;
  color: var(--paper-50);
}

.page-about .ab-join__d {
  font-size: 13px;
  line-height: 1.75;
  color: var(--on-dark-muted);
}

.page-about .ab-join__go {
  margin-top: 4px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--cyan-400);
}

.page-about .ab-join__foot {
  margin: 22px 0 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--on-dark-muted);
}

.page-about .ab-join__foot a {
  color: var(--cyan-400);
  text-decoration: none;
  border-bottom: 1px solid rgba(53, 242, 208, 0.42);
}

.page-about .ab-join__foot a:hover,
.page-about .ab-join__foot a:focus-visible {
  color: var(--orange-500);
  border-color: var(--orange-500);
}

/* ---------- 断点 ---------- */
@media (min-width: 640px) {
  .page-about .ab-scale {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

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

@media (min-width: 900px) {
  .page-about .ab-hero__grid {
    grid-template-columns: minmax(0, 1.5fr) minmax(260px, 1fr);
    gap: clamp(30px, 4vw, 56px);
    align-items: start;
  }

  .page-about .ab-sec__grid {
    grid-template-columns: minmax(120px, 168px) minmax(0, 1fr);
    gap: clamp(24px, 3.4vw, 48px);
  }

  .page-about .ab-sec__aside {
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
    position: sticky;
    top: 96px;
    align-self: start;
  }

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

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

  .page-about .ab-team__card:nth-child(1),
  .page-about .ab-team__card:nth-child(4) {
    grid-column: span 4;
  }

  .page-about .ab-team__card:nth-child(2),
  .page-about .ab-team__card:nth-child(3) {
    grid-column: span 2;
  }

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

@media (min-width: 1200px) {
  .page-about .ab-hero__rail {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .ab-sec__main > h2 {
    max-width: 26ch;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-team__card,
  .page-about .ab-join__card,
  .page-about .ab-quick__link,
  .page-about .ab-index__item {
    transition: none;
  }

  .page-about .ab-team__card:hover,
  .page-about .ab-join__card:hover,
  .page-about .ab-join__card:focus-visible {
    transform: none;
  }
}
<<<PAGE_CSS_END>>>