.page-about {
  --about-rail: 232px;
  --about-gap: 40px;
  --about-sec-gap: 72px;
  display: block;
  background: var(--ab-night);
  color: var(--ab-ink);
  overflow-x: clip;
}

.page-about .crumbs {
  padding-top: 22px;
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  position: relative;
  padding: 22px 0 56px;
  isolation: isolate;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -160px;
  right: -120px;
  width: min(620px, 82vw);
  height: 480px;
  background: radial-gradient(circle at 34% 34%, rgba(34, 224, 214, 0.2), transparent 64%);
  pointer-events: none;
  z-index: -1;
}

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

.page-about .about-hero__inner {
  display: grid;
  gap: 34px;
}

.page-about .about-hero__title {
  margin: 14px 0 0;
  font-size: clamp(30px, 6.4vw, 52px);
  line-height: 1.16;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--ab-ink);
}

.page-about .about-hero__lead {
  margin: 20px 0 26px;
  max-width: 60ch;
  color: var(--ab-mist);
  font-size: 16px;
  line-height: 1.85;
}

.page-about .about-hero__media {
  position: relative;
  isolation: isolate;
}

.page-about .about-hero__media::after {
  content: "";
  position: absolute;
  left: -10px;
  top: -10px;
  width: 64px;
  height: 3px;
  background: var(--ab-path);
}

/* ---------- 主体两栏：轨道 + 内容 ---------- */

.page-about .about-body {
  padding: 44px 0 0;
}

.page-about .about-body__inner {
  display: grid;
  gap: 32px;
}

/* 轨道（移动端为横向条） */

.page-about .about-track {
  border-bottom: 1px solid var(--ab-steel);
  padding-bottom: 14px;
}

.page-about .about-track__label {
  display: block;
  margin-bottom: 10px;
  color: var(--ab-path);
  font-size: 11px;
  letter-spacing: 0.18em;
}

.page-about .about-track__list {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 0 0 4px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: none;
}

.page-about .about-track__list::-webkit-scrollbar {
  display: none;
}

.page-about .about-track__link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  border: 1px solid var(--ab-steel);
  background: var(--ab-glass);
  color: var(--ab-ink);
  font-size: 13px;
  line-height: 1.3;
  white-space: nowrap;
  text-decoration: none;
  transition: border-color 160ms var(--ab-ease), background-color 160ms var(--ab-ease);
}

.page-about .about-track__node {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--ab-steel);
  flex: none;
  transition: background-color 160ms var(--ab-ease), box-shadow 160ms var(--ab-ease);
}

.page-about .about-track__link:hover,
.page-about .about-track__link:focus-visible {
  border-color: var(--ab-path);
  background: var(--ab-glass-strong);
}

.page-about .about-track__link:hover .about-track__node,
.page-about .about-track__link:focus-visible .about-track__node {
  background: var(--ab-path-soft);
  box-shadow: 0 0 10px rgba(123, 247, 238, 0.65);
}

/* 内容流 */

.page-about .about-flow {
  display: grid;
  gap: var(--about-sec-gap);
  min-width: 0;
}

.page-about .about-sec {
  scroll-margin-top: 90px;
}

.page-about .about-sec__head {
  margin-bottom: 20px;
}

.page-about .about-sec__head h2 {
  margin: 10px 0 0;
  font-size: clamp(23px, 3.4vw, 34px);
  line-height: 1.28;
  font-weight: 700;
  color: var(--ab-ink);
  max-width: 22ch;
}

.page-about .about-sec__lede {
  margin: 0 0 24px;
  max-width: 62ch;
  color: var(--ab-mist);
  font-size: 15px;
  line-height: 1.8;
}

.page-about .about-sec__prose p {
  margin: 0 0 16px;
  max-width: 66ch;
  color: var(--ab-ink);
  font-size: 15.5px;
  line-height: 1.9;
}

.page-about .about-sec__prose p:last-child {
  margin-bottom: 0;
}

.page-about .about-sec__actions {
  margin-top: 26px;
}

/* ---------- 横向图片带 ---------- */

.page-about .about-band {
  margin: 0;
  position: relative;
}

.page-about .about-band::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--ab-path), transparent 78%);
  pointer-events: none;
}

/* ---------- 团队环形图 ---------- */

.page-about .crew {
  display: grid;
  gap: 32px;
  align-items: center;
}

.page-about .crew__dial {
  width: 208px;
  height: 208px;
  margin: 0 auto;
  border-radius: 50%;
  display: grid;
  place-items: center;
  position: relative;
  background: conic-gradient(
    var(--ab-path) 0deg 141.43deg,
    var(--ab-path-soft) 141.43deg 218.57deg,
    var(--ab-amber) 218.57deg 321.43deg,
    var(--ab-steel) 321.43deg 360deg
  );
  box-shadow: 0 0 0 1px var(--ab-steel), var(--ab-shadow);
}

.page-about .crew__dial::after {
  content: "";
  position: absolute;
  inset: 26px;
  border-radius: 50%;
  background: var(--ab-stand);
}

.page-about .crew__dial-core {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: baseline;
  gap: 4px;
}

.page-about .crew__num {
  font-size: 48px;
  color: var(--ab-ink);
}

.page-about .crew__unit {
  font-size: 14px;
  color: var(--ab-mist);
}

.page-about .crew__list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 18px;
}

.page-about .crew__item {
  display: grid;
  grid-template-columns: 10px 1fr auto;
  gap: 10px;
  align-items: center;
  padding: 14px 0;
  border-bottom: 1px solid var(--ab-steel);
}

.page-about .crew__swatch {
  width: 10px;
  height: 10px;
  border-radius: 50%;
}

.page-about .crew__item--ops .crew__swatch { background: var(--ab-path); }
.page-about .crew__item--design .crew__swatch { background: var(--ab-path-soft); }
.page-about .crew__item--eng .crew__swatch { background: var(--ab-amber); }
.page-about .crew__item--support .crew__swatch { background: var(--ab-steel); }

.page-about .crew__role {
  font-size: 16px;
  font-weight: 600;
  color: var(--ab-ink);
}

.page-about .crew__count {
  font-size: 15px;
  color: var(--ab-path);
  letter-spacing: 0.02em;
}

.page-about .crew__desc {
  grid-column: 2 / -1;
  margin: 0;
  color: var(--ab-mist);
  font-size: 14px;
  line-height: 1.75;
}

/* ---------- 校对流程 ---------- */

.page-about .pipe {
  display: grid;
  gap: 26px;
}

.page-about .pipe__media {
  max-width: 320px;
  margin: 0;
}

.page-about .pipe__steps {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 0;
  counter-reset: none;
}

.page-about .pipe__step {
  position: relative;
  padding: 18px 0 18px 26px;
  border-left: 1px solid var(--ab-steel);
}

.page-about .pipe__step::before {
  content: "";
  position: absolute;
  left: -4px;
  top: 24px;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--ab-path);
  box-shadow: 0 0 8px rgba(34, 224, 214, 0.5);
}

.page-about .pipe__step:last-child {
  border-left-color: transparent;
}

.page-about .pipe__no {
  display: inline-block;
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--ab-amber);
}

.page-about .pipe__title {
  margin: 6px 0 8px;
  font-size: 18px;
  font-weight: 700;
  color: var(--ab-ink);
}

.page-about .pipe__step p {
  margin: 0;
  max-width: 58ch;
  color: var(--ab-mist);
  font-size: 14.5px;
  line-height: 1.85;
}

/* ---------- 版本时间线 ---------- */

.page-about .version-rail {
  display: flex;
  gap: 14px;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  padding: 6px 4px 20px;
  margin: 0 -4px;
  scrollbar-width: thin;
}

.page-about .version-rail:focus-visible {
  outline: 2px solid var(--ab-path);
  outline-offset: 4px;
}

.page-about .version-node {
  flex: 0 0 80%;
  scroll-snap-align: start;
  position: relative;
  padding: 22px 20px 24px;
  border: 1px solid var(--ab-steel);
  background: var(--ab-stand);
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.page-about .version-node::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 100%;
  height: 2px;
  background: var(--ab-steel);
}

.page-about .version-node__tag {
  margin: 0;
  font-size: 11.5px;
  letter-spacing: 0.16em;
  color: var(--ab-mist);
  text-transform: uppercase;
}

.page-about .version-node__title {
  margin: 0;
  font-size: 19px;
  font-weight: 700;
  line-height: 1.35;
  color: var(--ab-ink);
}

.page-about .version-node__body {
  margin: 0;
  color: var(--ab-mist);
  font-size: 14px;
  line-height: 1.85;
}

.page-about .version-node--key {
  border-color: var(--ab-path);
  background: linear-gradient(160deg, rgba(34, 224, 214, 0.14), var(--ab-stand) 62%);
}

.page-about .version-node--key::before {
  background: var(--ab-path);
}

.page-about .version-node--key .version-node__tag {
  color: var(--ab-path);
}

.page-about .version-node--wide .version-node__title {
  font-size: 24px;
}

.page-about .version-node__compare {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 6px;
}

/* ---------- 服务与支持 ---------- */

.page-about .reach {
  display: grid;
  gap: 26px;
}

.page-about .reach__stats {
  display: grid;
  gap: 14px;
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.page-about .reach__stat {
  padding: 16px 12px;
  border-left: 2px solid var(--ab-path);
  background: var(--ab-glass);
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-width: 0;
}

.page-about .reach__num {
  font-size: clamp(19px, 3.6vw, 27px);
  color: var(--ab-ink);
  line-height: 1.1;
}

.page-about .reach__label {
  font-size: 12px;
  color: var(--ab-mist);
  line-height: 1.5;
}

.page-about .reach__contact {
  display: grid;
  gap: 12px;
}

.page-about .reach__contact .muted {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--ab-mist);
}

.page-about .reach__list {
  margin: 4px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .reach__row {
  display: grid;
  grid-template-columns: 74px minmax(0, 1fr);
  gap: 10px;
  align-items: baseline;
  border-bottom: 1px solid var(--ab-steel);
  padding-bottom: 8px;
}

.page-about .reach__row dt {
  font-size: 12px;
  color: var(--ab-mist);
  letter-spacing: 0.06em;
}

.page-about .reach__row dd {
  margin: 0;
  font-family: var(--ab-mono);
  font-size: 13.5px;
  color: var(--ab-ink);
  word-break: break-all;
}

.page-about .reach__row dd a {
  color: var(--ab-path);
  text-decoration: none;
  border-bottom: 1px solid rgba(34, 224, 214, 0.4);
}

.page-about .reach__row dd a:hover {
  color: var(--ab-path-soft);
  border-bottom-color: var(--ab-path-soft);
}

.page-about .reach__contact .btn {
  justify-self: start;
}

/* ---------- 页尾回退 ---------- */

.page-about .about-foot {
  display: grid;
  gap: 14px;
  padding-top: 28px;
  border-top: 1px solid var(--ab-steel);
}

.page-about .about-foot__back {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  align-self: start;
  padding: 9px 16px;
  border: 1px solid var(--ab-path);
  color: var(--ab-path);
  font-size: 13px;
  text-decoration: none;
  transition: background-color 160ms var(--ab-ease), color 160ms var(--ab-ease);
}

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

.page-about .about-foot__note {
  margin: 0;
  max-width: 60ch;
  color: var(--ab-mist);
  font-size: 14px;
  line-height: 1.8;
}

.page-about .about-foot__note a {
  color: var(--ab-path);
  text-decoration: none;
  border-bottom: 1px solid rgba(34, 224, 214, 0.4);
}

.page-about .about-foot__note a:hover {
  color: var(--ab-path-soft);
}

/* ---------- 平板 ---------- */

@media (min-width: 768px) {
  .page-about .about-hero {
    padding: 34px 0 68px;
  }

  .page-about .about-body {
    padding-top: 56px;
  }

  .page-about .crew {
    grid-template-columns: 240px minmax(0, 1fr);
    gap: 40px;
  }

  .page-about .crew__dial {
    width: 232px;
    height: 232px;
    margin: 0;
  }

  .page-about .crew__num {
    font-size: 54px;
  }

  .page-about .pipe {
    grid-template-columns: 260px minmax(0, 1fr);
    gap: 36px;
    align-items: start;
  }

  .page-about .pipe__steps {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: 28px;
  }

  .page-about .version-node {
    flex: 0 0 300px;
  }

  .page-about .version-node--wide {
    flex: 0 0 460px;
  }

  .page-about .reach {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    gap: 32px;
    align-items: start;
  }

  .page-about .reach__stats {
    grid-template-columns: 1fr;
  }
}

/* ---------- 桌面 ---------- */

@media (min-width: 1080px) {
  .page-about .about-hero__inner {
    grid-template-columns: minmax(0, 1.02fr) minmax(0, 0.98fr);
    gap: 56px;
    align-items: end;
  }

  .page-about .about-hero__lead {
    font-size: 17px;
  }

  .page-about .about-body__inner {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: 56px;
    align-items: start;
  }

  .page-about .about-track {
    position: sticky;
    top: 92px;
    border-bottom: 0;
    border-left: 1px solid var(--ab-steel);
    padding: 4px 0 4px 20px;
    max-height: calc(100vh - 120px);
  }

  .page-about .about-track__label {
    writing-mode: vertical-rl;
    transform: rotate(180deg);
    position: absolute;
    left: -26px;
    top: 6px;
    margin: 0;
    color: var(--ab-path);
    letter-spacing: 0.24em;
    font-size: 10.5px;
  }

  .page-about .about-track__list {
    flex-direction: column;
    gap: 0;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .about-track__link {
    border: 0;
    background: transparent;
    padding: 11px 0;
    white-space: normal;
    font-size: 14px;
    color: var(--ab-mist);
    position: relative;
  }

  .page-about .about-track__link::before {
    content: "";
    position: absolute;
    left: -24px;
    top: 50%;
    width: 9px;
    height: 9px;
    margin-top: -4.5px;
    border-radius: 50%;
    border: 1px solid var(--ab-steel);
    background: var(--ab-night);
    transition: border-color 160ms var(--ab-ease), background-color 160ms var(--ab-ease), transform 160ms var(--ab-ease);
  }

  .page-about .about-track__link::after {
    content: "";
    position: absolute;
    left: -19.5px;
    top: 100%;
    width: 1px;
    height: calc(100% - 4px);
    background: var(--ab-steel);
  }

  .page-about .about-track__item:last-child .about-track__link::after {
    display: none;
  }

  .page-about .about-track__node {
    display: none;
  }

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

  .page-about .about-track__link:hover::before,
  .page-about .about-track__link:focus-visible::before {
    border-color: var(--ab-path);
    background: var(--ab-path-soft);
    transform: scale(1.35);
    box-shadow: 0 0 12px rgba(123, 247, 238, 0.6);
  }

  .page-about .about-flow {
    gap: 88px;
    min-width: 0;
  }

  .page-about .version-node {
    flex: 0 0 320px;
  }

  .page-about .version-node--wide {
    flex: 0 0 560px;
    grid-row: span 1;
  }
}

/* ---------- 大屏 ---------- */

@media (min-width: 1320px) {
  .page-about .about-flow {
    gap: 104px;
  }

  .page-about .version-node {
    flex: 0 0 340px;
  }

  .page-about .version-node--wide {
    flex: 0 0 620px;
  }
}

/* ---------- 动效适配 ---------- */

@media (prefers-reduced-motion: reduce) {
  .page-about .about-track__link,
  .page-about .about-track__node,
  .page-about .about-track__link::before,
  .page-about .about-foot__back {
    transition: none;
  }

  .page-about .version-rail {
    scroll-behavior: auto;
  }
}
<<<END>>>
</main>