.page-about {
  --ab-radius: 2px;
  --ab-glow: radial-gradient(circle at 14% 4%, rgba(53, 224, 214, 0.13), transparent 44%);
  background-image: var(--ab-glow);
  background-repeat: no-repeat;
  padding-bottom: var(--sp-6);
}

.page-about .crumbs {
  padding-top: var(--sp-2);
  padding-bottom: var(--sp-2);
}

/* ---------- 首屏 ---------- */

.page-about .ab-hero {
  position: relative;
  padding: var(--sp-4) 0 var(--sp-6);
  border-bottom: 1px solid var(--c-line-soft);
}

.page-about .ab-hero__grid {
  display: grid;
  gap: var(--sp-5);
}

.page-about .ab-hero__title {
  margin: var(--sp-2) 0 var(--sp-3);
  font-family: var(--f-head);
  font-weight: 800;
  font-size: clamp(2.1rem, 9vw, 4.6rem);
  line-height: 1.04;
  letter-spacing: -0.02em;
  color: var(--c-bone);
  overflow-wrap: break-word;
}

.page-about .ab-hero__lead {
  max-width: 48ch;
  margin: 0 0 var(--sp-4);
  font-size: 1.0625rem;
  line-height: 1.75;
  color: rgba(242, 239, 230, 0.82);
}

.page-about .ab-hero__acts {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-2);
}

.page-about .ab-keyfigs {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--c-line);
}

.page-about .ab-keyfigs li {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--sp-2);
  padding: 11px 0;
  border-bottom: 1px solid var(--c-line-soft);
}

.page-about .ab-keyfigs__num {
  font-family: var(--f-mono);
  font-variant-numeric: tabular-nums;
  font-size: 1.375rem;
  font-weight: 700;
  color: var(--c-cyan);
  letter-spacing: -0.01em;
}

.page-about .ab-keyfigs__lb {
  font-size: 0.875rem;
  color: var(--c-gray);
}

/* ---------- 通用区块 ---------- */

.page-about .ab-sec {
  padding: var(--sp-6) 0;
  border-bottom: 1px solid var(--c-line-soft);
}

.page-about .ab-sec:last-of-type {
  border-bottom: 0;
}

.page-about .ab-sec__head {
  display: grid;
  gap: var(--sp-2);
  margin-bottom: var(--sp-5);
}

.page-about .ab-sec .section-title {
  font-family: var(--f-head);
  font-weight: 800;
  font-size: clamp(1.5rem, 5vw, 2.5rem);
  line-height: 1.12;
  letter-spacing: -0.02em;
  color: var(--c-bone);
  margin: 0;
}

.page-about .ab-sec .section-lead {
  margin: 0;
  max-width: 52ch;
  font-size: 1rem;
  line-height: 1.75;
  color: rgba(242, 239, 230, 0.74);
}

/* ---------- 图片 ---------- */

.page-about .ab-figure {
  margin: 0 0 var(--sp-5);
  border: 1px solid var(--c-line);
  border-radius: var(--ab-radius);
  background: var(--c-deep);
  overflow: hidden;
}

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

.page-about .ab-figure__cap {
  padding: 10px var(--sp-2);
  font-size: 0.8125rem;
  line-height: 1.6;
  color: var(--c-gray);
  border-top: 1px solid var(--c-line-soft);
}

.page-about .ab-figure--net {
  margin-top: var(--sp-5);
  margin-bottom: var(--sp-5);
}

/* ---------- 分工技能树 ---------- */

.page-about .ab-tree {
  margin-top: var(--sp-4);
}

.page-about .ab-tree__trunk {
  display: inline-block;
  margin: 0 0 var(--sp-3);
  padding: 5px 12px;
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  color: var(--c-cyan);
  border: 1px solid rgba(53, 224, 214, 0.4);
  border-radius: var(--ab-radius);
}

.page-about .ab-tree__list {
  list-style: none;
  margin: 0;
  padding: 0 0 0 var(--sp-3);
  border-left: 1px solid var(--c-line);
  display: grid;
  gap: var(--sp-2);
}

.page-about .ab-tree__node {
  position: relative;
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  gap: var(--sp-2);
  padding: var(--sp-3) var(--sp-3) var(--sp-3) var(--sp-3);
  border: 1px solid var(--c-line-soft);
  border-radius: var(--ab-radius);
  background: rgba(7, 19, 34, 0.5);
  transition: border-color 0.18s ease, background-color 0.18s ease;
}

.page-about .ab-tree__node::before {
  content: "";
  position: absolute;
  top: 32px;
  left: calc(-1 * var(--sp-3) - 1px);
  width: var(--sp-3);
  height: 1px;
  background: var(--c-line);
  transition: background-color 0.18s ease;
}

.page-about .ab-tree__node:hover,
.page-about .ab-tree__node:focus-within {
  border-color: rgba(53, 224, 214, 0.6);
  background: rgba(53, 224, 214, 0.05);
}

.page-about .ab-tree__node:hover::before,
.page-about .ab-tree__node:focus-within::before {
  background: var(--c-cyan);
}

.page-about .ab-tree__idx {
  font-family: var(--f-mono);
  font-size: 0.8125rem;
  color: var(--c-gray);
  letter-spacing: 0.06em;
  padding-top: 3px;
}

.page-about .ab-tree__name {
  margin: 0 0 6px;
  font-family: var(--f-head);
  font-weight: 700;
  font-size: 1.0625rem;
  line-height: 1.35;
  color: var(--c-bone);
}

.page-about .ab-tree__name .mono {
  font-family: var(--f-mono);
  color: var(--c-cyan);
}

.page-about .ab-tree__body p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.72;
  color: rgba(242, 239, 230, 0.72);
}

/* ---------- 两个交付时刻 ---------- */

.page-about .ab-shifts {
  display: grid;
  gap: var(--sp-3);
}

.page-about .ab-shift {
  padding: var(--sp-4) var(--sp-3);
  border: 1px solid var(--c-line);
  border-top: 3px solid var(--c-cyan);
  border-radius: var(--ab-radius);
  background: linear-gradient(180deg, rgba(53, 224, 214, 0.06), rgba(7, 19, 34, 0.6));
}

.page-about .ab-shift--day {
  border-top-color: var(--c-orange);
  background: linear-gradient(180deg, rgba(255, 107, 44, 0.07), rgba(7, 19, 34, 0.6));
}

.page-about .ab-shift__top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--sp-2);
  margin-bottom: var(--sp-3);
}

.page-about .ab-shift__clock {
  font-family: var(--f-mono);
  font-variant-numeric: tabular-nums;
  font-size: 1.75rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--c-cyan);
}

.page-about .ab-shift--day .ab-shift__clock {
  color: var(--c-orange);
}

.page-about .ab-shift__badge {
  padding: 4px 10px;
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  color: var(--c-bone);
  border: 1px solid var(--c-line);
  border-radius: var(--ab-radius);
}

.page-about .ab-shift__title {
  margin: 0 0 var(--sp-3);
  font-family: var(--f-head);
  font-weight: 700;
  font-size: 1.25rem;
  line-height: 1.3;
  color: var(--c-bone);
}

.page-about .ab-shift__steps {
  list-style: none;
  margin: 0 0 var(--sp-3);
  padding: 0;
  display: grid;
  gap: 0;
}

.page-about .ab-shift__steps li {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 9px 0;
  font-size: 0.9375rem;
  line-height: 1.6;
  color: rgba(242, 239, 230, 0.8);
  border-bottom: 1px dashed var(--c-line-soft);
}

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

.page-about .ab-shift__step-lb {
  flex: none;
  width: 3.4em;
  font-family: var(--f-mono);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  color: var(--c-gray);
}

.page-about .ab-shift__foot {
  margin: 0;
  padding-top: var(--sp-2);
  border-top: 1px solid var(--c-line-soft);
  font-size: 0.875rem;
  line-height: 1.65;
  color: var(--c-gray);
}

.page-about .ab-shift__foot .mono {
  font-family: var(--f-mono);
  font-variant-numeric: tabular-nums;
  color: var(--c-bone);
}

/* ---------- 时间轴 ---------- */

.page-about .ab-hist {
  display: grid;
  gap: var(--sp-4);
}

.page-about .ab-hist .ab-figure {
  margin-bottom: 0;
}

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

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

.page-about .ab-tl__sum {
  display: grid;
  grid-template-columns: 74px minmax(0, 1fr) 18px;
  align-items: center;
  gap: var(--sp-2);
  padding: var(--sp-3) 0;
  cursor: pointer;
  list-style: none;
}

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

.page-about .ab-tl__sum:focus-visible {
  outline: 2px solid var(--c-cyan);
  outline-offset: 3px;
}

.page-about .ab-tl__year {
  font-family: var(--f-mono);
  font-variant-numeric: tabular-nums;
  font-size: 1.375rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--c-gray);
  transition: color 0.2s ease;
}

.page-about .ab-tl__item[open] .ab-tl__year {
  color: var(--c-cyan);
}

.page-about .ab-tl__label {
  font-family: var(--f-head);
  font-weight: 700;
  font-size: 1.0625rem;
  line-height: 1.35;
  color: var(--c-bone);
}

.page-about .ab-tl__mark {
  position: relative;
  width: 12px;
  height: 12px;
  border: 1px solid var(--c-gray);
  border-radius: 50%;
  justify-self: end;
  transition: border-color 0.2s ease, background-color 0.2s ease;
}

.page-about .ab-tl__item[open] .ab-tl__mark {
  border-color: var(--c-cyan);
  background: var(--c-cyan);
  box-shadow: 0 0 0 4px rgba(53, 224, 214, 0.14);
}

.page-about .ab-tl__panel {
  padding: 0 0 var(--sp-4) 0;
}

.page-about .ab-tl__panel p {
  margin: 0;
  max-width: 62ch;
  font-size: 0.9375rem;
  line-height: 1.78;
  color: rgba(242, 239, 230, 0.76);
}

/* ---------- 项目与来源 ---------- */

.page-about .ab-sports {
  list-style: none;
  margin: 0 0 var(--sp-4);
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .ab-sports__item {
  padding: 7px 14px;
  font-size: 0.875rem;
  color: var(--c-bone);
  border: 1px solid var(--c-line);
  border-radius: var(--ab-radius);
  background: rgba(7, 19, 34, 0.6);
}

.page-about .ab-src {
  position: relative;
  border: 1px solid var(--c-line);
  border-radius: var(--ab-radius);
  background: rgba(7, 19, 34, 0.5);
}

.page-about .ab-src__radio {
  position: absolute;
  width: 1px;
  height: 1px;
  opacity: 0;
  pointer-events: none;
}

.page-about .ab-src__tabs {
  display: flex;
  flex-wrap: wrap;
  border-bottom: 1px solid var(--c-line);
}

.page-about .ab-src__tab {
  flex: 1 1 auto;
  padding: 12px 14px;
  text-align: center;
  font-size: 0.875rem;
  color: var(--c-gray);
  cursor: pointer;
  border-right: 1px solid var(--c-line-soft);
  transition: color 0.18s ease, background-color 0.18s ease;
}

.page-about .ab-src__tab:last-child {
  border-right: 0;
}

.page-about .ab-src__tab:hover {
  color: var(--c-bone);
}

.page-about #ab-src-1:checked ~ .ab-src__tabs .ab-src__tab[for="ab-src-1"],
.page-about #ab-src-2:checked ~ .ab-src__tabs .ab-src__tab[for="ab-src-2"],
.page-about #ab-src-3:checked ~ .ab-src__tabs .ab-src__tab[for="ab-src-3"] {
  color: var(--c-ink);
  background: var(--c-cyan);
  font-weight: 600;
}

.page-about #ab-src-1:focus-visible ~ .ab-src__tabs .ab-src__tab[for="ab-src-1"],
.page-about #ab-src-2:focus-visible ~ .ab-src__tabs .ab-src__tab[for="ab-src-2"],
.page-about #ab-src-3:focus-visible ~ .ab-src__tabs .ab-src__tab[for="ab-src-3"] {
  outline: 2px solid var(--c-cyan);
  outline-offset: -3px;
}

.page-about .ab-src__panel {
  display: none;
  padding: var(--sp-4) var(--sp-3);
}

.page-about #ab-src-1:checked ~ .ab-src__panels .ab-src__panel--1,
.page-about #ab-src-2:checked ~ .ab-src__panels .ab-src__panel--2,
.page-about #ab-src-3:checked ~ .ab-src__panels .ab-src__panel--3 {
  display: block;
}

.page-about .ab-src__num {
  margin: 0 0 8px;
  font-family: var(--f-mono);
  font-variant-numeric: tabular-nums;
  font-size: 2rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--c-orange);
  line-height: 1;
}

.page-about .ab-src__panel--2 .ab-src__num {
  color: var(--c-yellow);
}

.page-about .ab-src__panel--3 .ab-src__num {
  color: var(--c-cyan);
}

.page-about .ab-src__txt {
  margin: 0;
  max-width: 64ch;
  font-size: 0.9375rem;
  line-height: 1.78;
  color: rgba(242, 239, 230, 0.78);
}

.page-about .ab-stats {
  margin-top: var(--sp-4);
  gap: 0;
  border-top: 1px solid var(--c-line);
  border-left: 1px solid var(--c-line);
}

.page-about .ab-stats .stat {
  padding: var(--sp-3);
  border-right: 1px solid var(--c-line);
  border-bottom: 1px solid var(--c-line);
  border-radius: var(--ab-radius);
}

.page-about .ab-stats .stat__value {
  font-family: var(--f-mono);
  font-variant-numeric: tabular-nums;
}

/* ---------- 三条坚持 ---------- */

.page-about .ab-pledge {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: var(--sp-3);
}

.page-about .ab-pledge__item {
  padding: var(--sp-3) 0 var(--sp-3) var(--sp-3);
  border-left: 2px solid var(--c-cyan);
}

.page-about .ab-pledge__mark {
  display: block;
  margin-bottom: 6px;
  font-size: 0.75rem;
  letter-spacing: 0.16em;
  color: var(--c-gray);
}

.page-about .ab-pledge__name {
  margin: 0 0 8px;
  font-family: var(--f-head);
  font-weight: 800;
  font-size: 1.25rem;
  line-height: 1.25;
  letter-spacing: -0.01em;
  color: var(--c-bone);
}

.page-about .ab-pledge__item p {
  margin: 0;
  max-width: 44ch;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: rgba(242, 239, 230, 0.74);
}

.page-about .ab-cta {
  margin-top: var(--sp-5);
  padding-top: var(--sp-4);
  border-top: 1px solid var(--c-line);
}

.page-about .ab-cta__txt {
  margin: 0 0 var(--sp-3);
  font-size: 1rem;
  line-height: 1.7;
  color: var(--c-bone);
}

.page-about .ab-cta__acts {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-2);
}

/* ---------- 响应式 ---------- */

@media (min-width: 700px) {
  .page-about .ab-shifts {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: var(--sp-4);
  }

  .page-about .ab-sports {
    gap: 10px;
  }

  .page-about .ab-src__tab {
    flex: 0 0 auto;
    min-width: 140px;
  }

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

  .page-about .ab-pledge {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: var(--sp-4);
  }

  .page-about .ab-tl__sum {
    grid-template-columns: 96px minmax(0, 1fr) 18px;
  }
}

@media (min-width: 960px) {
  .page-about .ab-hero {
    padding-top: var(--sp-5);
    padding-bottom: var(--sp-6);
  }

  .page-about .ab-hero__grid {
    grid-template-columns: minmax(0, 1.65fr) minmax(240px, 0.75fr);
    align-items: end;
    gap: var(--sp-6);
  }

  .page-about .ab-sec__head {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    align-items: end;
    gap: var(--sp-5);
  }

  .page-about .ab-hist {
    grid-template-columns: minmax(280px, 0.82fr) minmax(0, 1.55fr);
    gap: var(--sp-5);
    align-items: start;
  }

  .page-about .ab-hist .ab-figure {
    position: sticky;
    top: calc(var(--top-h) + var(--sp-3));
  }

  .page-about .ab-tree__list {
    padding-left: var(--sp-4);
  }

  .page-about .ab-tree__node {
    grid-template-columns: 44px minmax(0, 1fr);
    padding: var(--sp-3) var(--sp-4);
  }

  .page-about .ab-tree__node::before {
    left: calc(-1 * var(--sp-4) - 1px);
    width: var(--sp-4);
  }

  .page-about .ab-src__panel {
    padding: var(--sp-5) var(--sp-4);
  }

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

  .page-about .ab-pledge__item {
    padding-left: var(--sp-4);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-tree__node,
  .page-about .ab-tree__node::before,
  .page-about .ab-tl__year,
  .page-about .ab-tl__mark,
  .page-about .ab-src__tab {
    transition: none;
  }
}
<<<END>>>