.page-about {
  --ab-rail-w: 208px;
  --ab-tl-line: var(--grid);
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  position: relative;
  overflow: hidden;
  padding: 28px 0 52px;
  border-bottom: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(43, 232, 210, 0.055), rgba(6, 11, 24, 0) 62%);
}

.page-about .ab-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, var(--grid) 1px, transparent 1px),
    linear-gradient(to bottom, var(--grid) 1px, transparent 1px);
  background-size: 96px 96px;
  opacity: 0.42;
  pointer-events: none;
}

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

.page-about .ab-hero .breadcrumb {
  margin-bottom: 30px;
}

.page-about .ab-hero__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
}

.page-about .ab-hero__main .eyebrow {
  display: inline-block;
  margin: 0 0 14px;
  padding-bottom: 6px;
  border-bottom: 1px solid var(--line);
  color: var(--cyan-soft);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
}

.page-about .ab-hero h1 {
  margin: 0 0 18px;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(1.9rem, 7vw, 3.5rem);
  line-height: 1.12;
  letter-spacing: -0.03em;
  color: var(--title);
  max-width: 20em;
}

.page-about .ab-hero__lead {
  margin: 0;
  max-width: 34em;
  color: var(--text);
  font-size: 16.5px;
  line-height: 1.78;
}

.page-about .ab-hero__metric {
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding-bottom: 18px;
  border-bottom: 1px solid var(--line);
}

.page-about .ab-hero__metricnum {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(4.2rem, 18vw, 7.6rem);
  line-height: 0.86;
  letter-spacing: -0.04em;
  color: var(--cyan);
  -webkit-text-stroke: 0.7px var(--cyan);
  text-shadow: 0 0 30px rgba(43, 232, 210, 0.3);
}

.page-about .ab-hero__metriclabel {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--muted);
}

.page-about .ab-hero__mini {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  margin: 18px 0 0;
  background: var(--grid);
  border: 1px solid var(--grid);
}

.page-about .ab-hero__mini > div {
  background: var(--panel);
  padding: 12px 10px;
}

.page-about .ab-hero__mini dt {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--muted);
}

.page-about .ab-hero__mini dd {
  margin: 7px 0 0;
  font-family: var(--font-mono);
  font-size: 16px;
  font-weight: 700;
  color: var(--title);
}

/* ---------- 布局骨架 ---------- */
.page-about .ab-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
  padding-top: 34px;
  padding-bottom: 72px;
}

.page-about .ab-rail {
  padding-bottom: 18px;
  margin-bottom: 8px;
  border-bottom: 1px solid var(--line);
}

.page-about .ab-rail__title {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--muted);
}

.page-about .ab-rail__list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 14px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-rail__link {
  display: inline-block;
  padding: 4px 0;
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--t-fast), border-color var(--t-fast);
}

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

/* ---------- 章节 ---------- */
.page-about .ab-body {
  min-width: 0;
}

.page-about .ab-sec {
  padding: 40px 0;
  border-top: 1px solid var(--grid);
}

.page-about .ab-sec:first-child {
  border-top: 0;
  padding-top: 24px;
}

.page-about .ab-datastrip {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
  margin: 0 0 18px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--grid);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--muted);
}

.page-about .ab-datastrip__dot {
  width: 5px;
  height: 5px;
  background: var(--cyan);
  box-shadow: 0 0 8px rgba(43, 232, 210, 0.7);
}

.page-about .ab-datastrip__v {
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--cyan);
}

.page-about .ab-datastrip__n {
  color: var(--muted);
}

.page-about .ab-sec h2 {
  margin: 0 0 18px;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(1.5rem, 5vw, 2.15rem);
  line-height: 1.14;
  letter-spacing: -0.03em;
  color: var(--title);
}

.page-about .ab-sec > p {
  margin: 0 0 16px;
  max-width: 38em;
  color: var(--text);
  font-size: 16.5px;
  line-height: 1.78;
}

.page-about .ab-sec a {
  color: var(--cyan-soft);
  text-decoration: none;
  border-bottom: 1px solid var(--line);
  transition: border-color var(--t-fast), color var(--t-fast);
}

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

/* ---------- 数据链路 ---------- */
.page-about .ab-chainmap {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  margin: 26px 0 0;
  background: var(--grid);
  border: 1px solid var(--grid);
}

.page-about .ab-chain {
  position: relative;
  padding: 20px 18px 22px;
  background: var(--panel);
  transition: background var(--t-fast), box-shadow var(--t-fast);
}

.page-about .ab-chain::before {
  content: "";
  position: absolute;
  inset: 0;
  border: 1px solid transparent;
  pointer-events: none;
  transition: border-color var(--t-fast);
}

.page-about .ab-chain:hover::before,
.page-about .ab-chain:focus-within::before {
  border-color: var(--line);
}

.page-about .ab-chain__num {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--orange);
}

.page-about .ab-chain__name {
  margin: 0 0 10px;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: 17px;
  letter-spacing: -0.01em;
  color: var(--title);
}

.page-about .ab-chain__brief {
  margin: 0;
  color: var(--text);
  font-size: 15px;
  line-height: 1.72;
}

.page-about .ab-chain__more {
  margin-top: 14px;
  padding-top: 12px;
  border-top: 1px solid var(--grid);
}

.page-about .ab-chain__more summary {
  cursor: pointer;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.1em;
  color: var(--cyan-soft);
  transition: color var(--t-fast);
}

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

.page-about .ab-chain__more summary::after {
  content: " +";
  font-family: var(--font-mono);
}

.page-about .ab-chain__more[open] summary::after {
  content: " −";
}

.page-about .ab-chain__more summary:hover {
  color: var(--cyan);
}

.page-about .ab-chain__more p {
  margin: 10px 0 0;
  color: var(--muted);
  font-size: 14.5px;
  line-height: 1.72;
}

.page-about .ab-pipefig {
  margin: 26px 0 0;
}

/* ---------- 团队 ---------- */
.page-about .ab-roles {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  margin: 26px 0 0;
  padding: 0;
  background: var(--grid);
  border: 1px solid var(--grid);
  list-style: none;
}

.page-about .ab-role {
  padding: 20px 18px;
  background: var(--panel);
  border-left: 2px solid transparent;
  transition: border-color var(--t-fast);
}

.page-about .ab-role:hover {
  border-left-color: var(--cyan);
}

.page-about .ab-role__title {
  margin: 0 0 8px;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: 16.5px;
  letter-spacing: -0.01em;
  color: var(--title);
}

.page-about .ab-role__desc {
  margin: 0;
  color: var(--text);
  font-size: 15px;
  line-height: 1.74;
}

/* ---------- 服务版图 ---------- */
.page-about .ab-map {
  position: relative;
  margin-top: 26px;
  border: 1px solid var(--line);
  background: var(--panel);
  overflow: hidden;
  min-height: 320px;
}

.page-about .ab-map__media {
  position: absolute;
  inset: 0;
}

.page-about .ab-map__media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.55;
}

.page-about .ab-map__veil {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(102deg, rgba(6, 11, 24, 0.95) 0%, rgba(6, 11, 24, 0.8) 48%, rgba(6, 11, 24, 0.34) 100%),
    linear-gradient(0deg, rgba(255, 196, 107, 0.07), rgba(255, 196, 107, 0) 55%);
}

.page-about .ab-map__inner {
  position: relative;
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
  padding: 26px 20px;
}

.page-about .ab-map__cell h3 {
  margin: 0 0 8px;
  padding-bottom: 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--gold);
  border-bottom: 1px solid rgba(255, 196, 107, 0.28);
}

.page-about .ab-map__cell p {
  margin: 0;
  color: var(--text);
  font-size: 15px;
  line-height: 1.74;
}

/* ---------- 版本时间轴 ---------- */
.page-about .ab-tlfig {
  margin: 26px 0 30px;
}

.page-about .ab-timeline {
  position: relative;
  margin: 0;
  padding: 4px 0 4px 30px;
  list-style: none;
}

.page-about .ab-timeline::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 10px;
  bottom: 10px;
  width: 1px;
  background: linear-gradient(180deg, var(--cyan) 0%, var(--line) 45%, var(--grid) 100%);
}

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

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

.page-about .ab-timeline__dot {
  position: absolute;
  left: -30px;
  top: 7px;
  width: 9px;
  height: 9px;
  background: var(--bg);
  border: 1px solid var(--line);
  transition: border-color var(--t-fast), background var(--t-fast), box-shadow var(--t-fast);
}

.page-about .ab-timeline__item:hover .ab-timeline__dot,
.page-about .ab-timeline__item:focus-within .ab-timeline__dot {
  border-color: var(--cyan);
  background: var(--cyan);
  box-shadow: 0 0 12px rgba(43, 232, 210, 0.6);
}

.page-about .ab-timeline__meta {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 0 0 6px;
  font-family: var(--font-mono);
}

.page-about .ab-timeline__year {
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--cyan);
}

.page-about .ab-timeline__tag {
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--muted);
  padding: 2px 7px;
  border: 1px solid var(--line);
}

.page-about .ab-timeline__name {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: 16.5px;
  letter-spacing: -0.01em;
  color: var(--title);
}

.page-about .ab-timeline__desc {
  margin: 8px 0 0;
  max-width: 42em;
  color: var(--text);
  font-size: 15px;
  line-height: 1.74;
}

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

/* ---------- 底部行动 ---------- */
.page-about .ab-cta {
  border-top: 1px solid var(--line);
  background: var(--panel);
}

.page-about .ab-cta__inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: 22px;
  padding-top: 42px;
  padding-bottom: 42px;
}

.page-about .ab-cta__text h2 {
  margin: 0 0 10px;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(1.35rem, 4.6vw, 1.85rem);
  line-height: 1.16;
  letter-spacing: -0.03em;
  color: var(--title);
}

.page-about .ab-cta__text p {
  margin: 0;
  max-width: 34em;
  color: var(--text);
  font-size: 15.5px;
  line-height: 1.74;
}

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

.page-about .ab-cta__actions .btn {
  text-decoration: none;
}

/* ---------- 响应式 ---------- */
@media (min-width: 700px) {
  .page-about .ab-hero {
    padding: 36px 0 62px;
  }

  .page-about .ab-hero__grid {
    grid-template-columns: minmax(0, 1.65fr) minmax(0, 1fr);
    gap: 48px;
    align-items: end;
  }

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

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

  .page-about .ab-map__inner {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 26px;
    padding: 34px 28px;
  }

  .page-about .ab-cta__inner {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    padding-top: 48px;
    padding-bottom: 48px;
  }
}

@media (min-width: 960px) {
  .page-about .ab-hero {
    padding: 44px 0 72px;
  }

  .page-about .ab-layout {
    grid-template-columns: var(--ab-rail-w) minmax(0, 1fr);
    gap: 68px;
    padding-top: 46px;
    padding-bottom: 96px;
  }

  .page-about .ab-rail {
    position: sticky;
    top: 96px;
    align-self: start;
    padding-bottom: 0;
    margin-bottom: 0;
    border-bottom: 0;
  }

  .page-about .ab-rail__list {
    flex-direction: column;
    gap: 0;
  }

  .page-about .ab-rail__link {
    display: block;
    padding: 9px 0 9px 14px;
    border-bottom: 0;
    border-left: 1px solid var(--grid);
    font-size: 12.5px;
    letter-spacing: 0.08em;
  }

  .page-about .ab-rail__link:hover,
  .page-about .ab-rail__link:focus-visible,
  .page-about .ab-rail__link.is-active {
    color: var(--cyan);
    border-left-color: var(--cyan);
    border-bottom-color: transparent;
  }

  .page-about .ab-sec {
    padding: 56px 0;
  }

  .page-about .ab-sec:first-child {
    padding-top: 0;
  }

  .page-about .ab-map {
    min-height: 400px;
  }
}

/* 支持悬停的设备：时间轴说明在指针停留时展开 */
@media (min-width: 900px) and (hover: hover) {
  .page-about .ab-timeline__desc {
    display: grid;
    grid-template-rows: 0fr;
    opacity: 0;
    margin-top: 0;
    transition: grid-template-rows var(--t-med), opacity var(--t-med), margin-top var(--t-med);
  }

  .page-about .ab-timeline__desc > p {
    overflow: hidden;
    min-height: 0;
  }

  .page-about .ab-timeline__item:hover .ab-timeline__desc,
  .page-about .ab-timeline__item:focus .ab-timeline__desc,
  .page-about .ab-timeline__item:focus-within .ab-timeline__desc {
    grid-template-rows: 1fr;
    opacity: 1;
    margin-top: 9px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-timeline__desc,
  .page-about .ab-timeline__dot,
  .page-about .ab-role,
  .page-about .ab-chain::before {
    transition: none;
  }
}
</style>
<<<END>>>
```