.page-about {
  display: block;
  overflow-x: clip;
}

/* ---------- 首屏 ---------- */

.page-about .ab-hero {
  position: relative;
  padding-top: calc(var(--header-h) + clamp(48px, 8vw, 92px));
  padding-bottom: clamp(40px, 6vw, 72px);
  background:
    radial-gradient(110% 85% at 88% -12%, rgba(46, 242, 179, .15), transparent 62%),
    radial-gradient(95% 75% at -12% 112%, rgba(27, 20, 64, .88), transparent 68%);
}

.page-about .ab-hero::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1px;
  background: linear-gradient(90deg, var(--cyan), transparent 62%);
  opacity: .45;
}

.page-about .ab-hero .breadcrumb {
  margin-bottom: clamp(24px, 3.4vw, 42px);
}

.page-about .ab-hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(32px, 5vw, 64px);
  align-items: end;
}

.page-about .ab-kicker {
  margin: 0 0 14px;
  font-family: var(--font-display);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--cyan);
}

.page-about .ab-hero h1 {
  margin: 0 0 20px;
  font-family: var(--font-display);
  font-size: clamp(2.1rem, 5.4vw, 3.9rem);
  font-weight: 700;
  line-height: 1.06;
  letter-spacing: .01em;
  color: var(--text);
  max-width: 19ch;
}

.page-about .ab-lede {
  margin: 0 0 30px;
  font-family: var(--font-body);
  font-size: clamp(1rem, 1.1vw, 1.0625rem);
  line-height: 1.8;
  color: var(--muted);
  max-width: 56ch;
}

.page-about .ab-hero-figures {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 0;
  padding: 0;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .ab-hero-figures > div {
  background: rgba(4, 22, 15, .78);
  padding: 16px 14px 18px;
}

.page-about .ab-hero-figures dt {
  margin: 0 0 8px;
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--muted);
}

.page-about .ab-hero-figures dd {
  margin: 0;
  font-family: var(--font-num);
  font-size: clamp(1.05rem, 1.5vw, 1.3rem);
  line-height: 1.15;
  color: var(--cyan);
  white-space: nowrap;
}

.page-about .ab-hero-figures > div:nth-child(2) dd,
.page-about .ab-hero-figures > div:nth-child(4) dd {
  color: var(--amber);
}

/* ---------- 通栏图 ---------- */

.page-about .ab-banner {
  padding-bottom: clamp(52px, 7vw, 96px);
  background: linear-gradient(180deg, transparent, rgba(27, 20, 64, .5) 70%, transparent);
}

.page-about .ab-banner-frame,
.page-about .ab-flow-media,
.page-about .ab-reach-media {
  margin: 0;
  border: 1px solid var(--line-strong);
  background: var(--bg-raised);
  overflow: hidden;
}

.page-about .ab-banner-frame img,
.page-about .ab-flow-media img,
.page-about .ab-reach-media img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  filter: saturate(.92) contrast(1.04);
}

.page-about .ab-banner-frame figcaption,
.page-about .ab-flow-media figcaption,
.page-about .ab-reach-media figcaption {
  padding: 12px 16px 14px;
  font-size: .8125rem;
  line-height: 1.6;
  color: var(--muted);
  border-top: 1px solid var(--line);
}

/* ---------- 章节通用 ---------- */

.page-about .ab-section .section-head {
  margin-bottom: clamp(32px, 4.5vw, 58px);
}

.page-about .ab-section .section-title {
  color: var(--text);
  max-width: 26ch;
}

.page-about .ab-section .section-lead {
  max-width: 62ch;
}

/* ---------- 01 三条线 ---------- */

.page-about .ab-lines {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line);
  border-top: 1px solid var(--line-strong);
  border-bottom: 1px solid var(--line-strong);
}

.page-about .ab-line {
  position: relative;
  padding: clamp(26px, 3.4vw, 40px) clamp(18px, 2.4vw, 30px);
  background: var(--bg);
  transition: background var(--t) var(--ease), transform var(--t) var(--ease);
}

.page-about .ab-line::before {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: 2px;
  background: var(--line-strong);
  transition: background var(--t) var(--ease);
}

.page-about .ab-line:hover,
.page-about .ab-line:focus-within {
  background: var(--bg-raised);
  transform: translateY(-2px);
}

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

.page-about .ab-line-no {
  margin: 0 0 14px;
  font-family: var(--font-num);
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--muted);
}

.page-about .ab-line-title {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-size: clamp(1.15rem, 1.8vw, 1.4rem);
  font-weight: 700;
  line-height: 1.2;
  color: var(--text);
}

.page-about .ab-line-role {
  margin: 0 0 14px;
  font-size: .8125rem;
  letter-spacing: .08em;
  color: var(--cyan);
}

.page-about .ab-line-num {
  font-family: var(--font-num);
  font-size: 1.35em;
  color: var(--amber);
  margin-right: 2px;
}

.page-about .ab-line p:last-child {
  margin: 0;
  font-size: .9375rem;
  line-height: 1.78;
  color: var(--muted);
}

/* ---------- 02 覆盖范围 ---------- */

.page-about .ab-coverage {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(30px, 4.5vw, 60px);
  align-items: center;
}

.page-about .ab-ring-wrap {
  position: relative;
  width: min(290px, 78%);
  margin: 0 auto;
}

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

.page-about .ab-ring-track {
  fill: none;
  stroke: var(--line);
  stroke-width: 13;
}

.page-about .ab-ring-seg {
  fill: none;
  stroke-width: 13;
  opacity: .88;
  transition: stroke-width 200ms var(--ease), opacity 200ms var(--ease);
}

.page-about .ab-ring-seg--a { stroke: var(--cyan); }
.page-about .ab-ring-seg--b { stroke: var(--amber); }
.page-about .ab-ring-seg--c { stroke: var(--orange); }
.page-about .ab-ring-seg--d { stroke: var(--muted); }

.page-about .ab-ring-seg:hover {
  stroke-width: 19;
  opacity: 1;
}

.page-about .ab-ring-center {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 6px;
  pointer-events: none;
  text-align: center;
}

.page-about .ab-ring-num {
  font-family: var(--font-num);
  font-size: clamp(2.2rem, 5.2vw, 3.1rem);
  font-weight: 700;
  line-height: 1;
  color: var(--text);
}

.page-about .ab-ring-cap {
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--muted);
}

.page-about .ab-coverage-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .ab-coverage-item {
  position: relative;
  background: var(--bg-raised);
  padding: 20px 20px 22px 24px;
  transition: background var(--t) var(--ease);
}

.page-about .ab-coverage-item:hover {
  background: #0E3329;
}

.page-about .ab-coverage-key {
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
}

.page-about .ab-coverage-key--a { background: var(--cyan); }
.page-about .ab-coverage-key--b { background: var(--amber); }
.page-about .ab-coverage-key--c { background: var(--orange); }
.page-about .ab-coverage-key--d { background: var(--muted); }

.page-about .ab-coverage-item h3 {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-size: 1.0625rem;
  font-weight: 700;
  line-height: 1.25;
  color: var(--text);
}

.page-about .ab-coverage-item p {
  margin: 0;
  font-size: .90625rem;
  line-height: 1.75;
  color: var(--muted);
}

.page-about .ab-coverage-foot {
  margin: clamp(26px, 3.4vw, 40px) 0 0;
  padding-left: 18px;
  border-left: 2px solid var(--cyan);
  font-size: .9375rem;
  line-height: 1.78;
  color: var(--text);
}

/* ---------- 03 时间轴 ---------- */

.page-about .ab-flow {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(30px, 4.5vw, 56px);
  align-items: start;
}

.page-about .ab-timeline {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  border-top: 1px solid var(--line-strong);
}

.page-about .ab-node {
  position: relative;
  padding: 30px 18px 26px 0;
  border-bottom: 1px solid var(--line);
  transition: background var(--t) var(--ease);
}

.page-about .ab-node:focus {
  outline: 2px solid var(--cyan);
  outline-offset: -2px;
}

.page-about .ab-node:hover {
  background: rgba(10, 42, 33, .6);
}

.page-about .ab-node-tick {
  position: absolute;
  top: -5px;
  left: 0;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--bg);
  border: 2px solid var(--cyan);
}

.page-about .ab-node:last-child .ab-node-tick {
  background: var(--orange);
  border-color: var(--orange);
}

.page-about .ab-node-time {
  margin: 0 0 12px;
  font-family: var(--font-num);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--cyan);
}

.page-about .ab-node-title {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 700;
  line-height: 1.25;
  color: var(--text);
}

.page-about .ab-node-sum {
  margin: 0;
  font-size: .90625rem;
  line-height: 1.74;
  color: var(--muted);
}

.page-about .ab-node-extra {
  max-height: 0;
  overflow: hidden;
  opacity: 0;
  margin: 0;
  font-size: .875rem;
  line-height: 1.7;
  color: var(--text);
  border-left: 1px solid var(--cyan);
  padding-left: 0;
  transition: max-height 260ms var(--ease), opacity 200ms var(--ease),
              margin 260ms var(--ease), padding 260ms var(--ease);
}

.page-about .ab-node:hover .ab-node-extra,
.page-about .ab-node:focus .ab-node-extra,
.page-about .ab-node:focus-within .ab-node-extra {
  max-height: 160px;
  opacity: 1;
  margin-top: 12px;
  padding-left: 12px;
}

/* ---------- 04 班组 ---------- */

.page-about .ab-squad {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line-strong);
  border: 1px solid var(--line-strong);
}

.page-about .ab-squad-cell {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 26px 20px 30px;
  background: var(--bg-raised);
  transition: background var(--t) var(--ease), transform var(--t) var(--ease);
}

.page-about .ab-squad-cell::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--line-strong);
  transition: background var(--t) var(--ease);
}

.page-about .ab-squad-cell:hover,
.page-about .ab-squad-cell:focus-within {
  background: #10382C;
  transform: translateY(-2px);
}

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

.page-about .ab-squad-cell:nth-child(2)::before { background: rgba(245, 199, 97, .5); }
.page-about .ab-squad-cell:nth-child(3)::before { background: rgba(255, 106, 31, .5); }
.page-about .ab-squad-cell:nth-child(4)::before { background: rgba(143, 168, 162, .5); }

.page-about .ab-squad-num {
  margin: 0;
  font-family: var(--font-num);
  font-size: clamp(2rem, 4.4vw, 2.8rem);
  font-weight: 700;
  line-height: 1;
  color: var(--cyan);
}

.page-about .ab-squad-cell:nth-child(2) .ab-squad-num { color: var(--amber); }
.page-about .ab-squad-cell:nth-child(3) .ab-squad-num { color: var(--orange); }
.page-about .ab-squad-cell:nth-child(4) .ab-squad-num { color: var(--muted); }

.page-about .ab-squad-name {
  margin: 0;
  font-family: var(--font-display);
  font-size: 1.0625rem;
  font-weight: 700;
  letter-spacing: .04em;
  color: var(--text);
}

.page-about .ab-squad-cell p:last-child {
  margin: 0;
  font-size: .90625rem;
  line-height: 1.76;
  color: var(--muted);
}

.page-about .ab-squad-note {
  margin-top: clamp(28px, 3.6vw, 44px);
  padding: clamp(20px, 2.6vw, 30px);
  border: 1px solid var(--line-strong);
  border-left: 3px solid var(--amber);
  background: rgba(4, 22, 15, .6);
}

.page-about .ab-squad-note p {
  margin: 0;
  font-size: .9375rem;
  line-height: 1.8;
  color: var(--text);
  max-width: 74ch;
}

/* ---------- 05 发展阶段 ---------- */

.page-about .ab-phases {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
}

.page-about .ab-phase {
  position: relative;
  padding: 0 0 clamp(24px, 3vw, 36px) clamp(24px, 3vw, 40px);
  border-left: 1px solid var(--line);
}

.page-about .ab-phase:last-child {
  padding-bottom: 0;
}

.page-about .ab-phase::before {
  content: "";
  position: absolute;
  left: -5px;
  top: 6px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--bg);
  border: 2px solid var(--line-strong);
}

.page-about .ab-phase:last-child::before {
  border-color: var(--orange);
  background: var(--orange);
}

.page-about .ab-phase-epoch {
  display: inline-block;
  margin-bottom: 10px;
  font-family: var(--font-num);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--cyan);
}

.page-about .ab-phase:last-child .ab-phase-epoch {
  color: var(--orange);
}

.page-about .ab-phase-title {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-size: clamp(1.05rem, 1.5vw, 1.2rem);
  font-weight: 700;
  line-height: 1.3;
  color: var(--text);
}

.page-about .ab-phase p {
  margin: 0;
  font-size: .9375rem;
  line-height: 1.78;
  color: var(--muted);
  max-width: 74ch;
}

/* ---------- 06 准确性 ---------- */

.page-about .ab-accuracy {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .ab-accuracy-item {
  padding: clamp(22px, 3vw, 34px);
  background: var(--bg-raised);
  transition: background var(--t) var(--ease);
}

.page-about .ab-accuracy-item:hover {
  background: #0E3329;
}

.page-about .ab-accuracy-no {
  margin: 0 0 14px;
  font-family: var(--font-num);
  font-size: 13px;
  letter-spacing: .18em;
  color: var(--orange);
}

.page-about .ab-accuracy-item h3 {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-size: 1.0625rem;
  font-weight: 700;
  line-height: 1.28;
  color: var(--text);
}

.page-about .ab-accuracy-item p {
  margin: 0;
  font-size: .90625rem;
  line-height: 1.78;
  color: var(--muted);
}

/* ---------- 07 服务与联络 ---------- */

.page-about .ab-reach {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(28px, 4vw, 52px);
  align-items: start;
}

.page-about .ab-reach-sub {
  margin: 0 0 18px;
  font-family: var(--font-display);
  font-size: 1.0625rem;
  font-weight: 700;
  letter-spacing: .04em;
  color: var(--cyan);
}

.page-about .ab-reach-list {
  list-style: none;
  margin: 0 0 22px;
  padding: 0;
  border-top: 1px solid var(--line);
}

.page-about .ab-reach-list li {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 4px;
  padding: 14px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .ab-reach-key {
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--muted);
}

.page-about .ab-reach-list li > a,
.page-about .ab-reach-list li > span:last-child {
  font-family: var(--font-num);
  font-size: .9375rem;
  line-height: 1.6;
  color: var(--text);
  word-break: break-word;
}

.page-about .ab-reach-list li > a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(46, 242, 179, .4);
}

.page-about .ab-reach-list li > a:hover,
.page-about .ab-reach-list li > a:focus-visible {
  border-bottom-color: var(--cyan);
}

.page-about .ab-reach-note {
  margin: 0 0 24px;
  font-size: .90625rem;
  line-height: 1.78;
  color: var(--muted);
  max-width: 62ch;
}

.page-about .ab-cross {
  margin-top: clamp(32px, 4.4vw, 56px);
  padding-top: clamp(22px, 2.8vw, 32px);
  border-top: 1px solid var(--line-strong);
}

.page-about .ab-cross p {
  margin: 0;
  font-size: .9375rem;
  line-height: 1.85;
  color: var(--muted);
  max-width: 78ch;
}

.page-about .ab-cross a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(46, 242, 179, .4);
}

.page-about .ab-cross a:hover,
.page-about .ab-cross a:focus-visible {
  border-bottom-color: var(--cyan);
}

/* ---------- 响应式 ---------- */

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

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

  .page-about .ab-reach-list li {
    grid-template-columns: 108px minmax(0, 1fr);
    align-items: baseline;
    gap: 12px;
  }

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

@media (min-width: 900px) {
  .page-about .ab-accuracy {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .ab-squad {
    grid-template-columns: 32fr 21fr 18fr 15fr;
  }
}

@media (min-width: 1024px) {
  .page-about .ab-hero-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
  }

  .page-about .ab-coverage {
    grid-template-columns: minmax(0, 4fr) minmax(0, 7fr);
  }

  .page-about .ab-flow {
    grid-template-columns: minmax(0, 5fr) minmax(0, 6fr);
  }

  .page-about .ab-timeline {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    border-top: 1px solid var(--line-strong);
  }

  .page-about .ab-node {
    padding: 34px 20px 30px 22px;
    border-bottom: 0;
    border-right: 1px solid var(--line);
  }

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

  .page-about .ab-node-tick {
    left: 22px;
  }

  .page-about .ab-node-extra {
    padding-left: 0;
  }

  .page-about .ab-reach {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-line,
  .page-about .ab-squad-cell,
  .page-about .ab-node-extra,
  .page-about .ab-ring-seg {
    transition: none;
  }

  .page-about .ab-line:hover,
  .page-about .ab-squad-cell:hover,
  .page-about .ab-squad-cell:focus-within {
    transform: none;
  }
}
<<<END>>>