.page-about {
  --ab-toc-w: 236px;
  background: var(--ink-900);
  color: var(--white);
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  position: relative;
  overflow: hidden;
  padding: calc(var(--header-total) + 48px) 0 56px;
}

.page-about .ab-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid) 1px, transparent 1px);
  background-size: 48px 48px;
  opacity: 0.45;
  -webkit-mask-image: radial-gradient(ellipse 92% 72% at 28% 42%, #000 0%, transparent 76%);
  mask-image: radial-gradient(ellipse 92% 72% at 28% 42%, #000 0%, transparent 76%);
  pointer-events: none;
}

.page-about .ab-hero::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--cyan) 45%, var(--violet) 55%, transparent);
  opacity: 0.6;
}

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

.page-about .ab-hero__grid {
  display: grid;
  gap: 34px;
  margin-top: 26px;
}

.page-about .ab-hero h1 {
  font-size: var(--fs-display);
  font-weight: 900;
  line-height: 1.06;
  letter-spacing: -0.02em;
  margin: 14px 0 20px;
  max-width: 20ch;
}

.page-about .ab-hero__intro {
  margin: 0 0 26px;
  max-width: 62ch;
  font-size: 17px;
  line-height: 1.78;
  color: var(--dim);
}

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

.page-about .ab-terminal {
  position: relative;
  border: var(--line);
  background: var(--panel);
}

.page-about .ab-terminal::after {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 48px;
  height: 1px;
  background: var(--cyan);
}

.page-about .ab-terminal__bar {
  margin: 0;
  padding: 11px 18px;
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--cyan);
  background: var(--panel-2);
  border-bottom: var(--line);
}

.page-about .ab-terminal__list {
  margin: 0;
  padding: 4px 18px 8px;
}

.page-about .ab-terminal__row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  padding: 11px 0;
  border-bottom: 1px solid var(--grid);
}

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

.page-about .ab-terminal__row dt {
  font-size: 14px;
  color: var(--dim);
}

.page-about .ab-terminal__row dd {
  margin: 0;
  font-size: 15px;
  font-weight: 700;
  color: var(--white);
}

/* ---------- 主体框架 ---------- */
.page-about .ab-body {
  display: grid;
  gap: 38px;
  padding-top: 46px;
  padding-bottom: 72px;
}

.page-about .ab-content {
  min-width: 0;
}

.page-about .ab-toc__title {
  display: none;
  margin: 0 0 10px;
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--dim);
}

.page-about .ab-toc__list {
  list-style: none;
  margin: 0;
  padding: 0 0 6px;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .ab-toc__link {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 9px 13px;
  border: 1px solid var(--grid);
  background: var(--panel);
  color: var(--dim);
  text-decoration: none;
  font-size: 13px;
  white-space: nowrap;
  transition: color 0.16s ease, border-color 0.16s ease, background 0.16s ease;
}

.page-about .ab-toc__link:hover,
.page-about .ab-toc__link:focus-visible {
  color: var(--white);
  border-color: var(--cyan);
}

.page-about .ab-toc__idx {
  flex: none;
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--cyan);
}

/* ---------- 章节 ---------- */
.page-about .ab-sec {
  padding: 40px 0;
  border-top: var(--line);
  scroll-margin-top: calc(var(--header-total) + 20px);
}

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

.page-about .ab-sec__head {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 16px;
}

.page-about .ab-sec__no {
  flex: none;
  padding: 3px 8px;
  font-size: 11px;
  line-height: 1;
  letter-spacing: 0.08em;
  color: var(--cyan);
  border: 1px solid var(--grid);
}

.page-about .ab-sec h2 {
  margin: 0;
  font-size: var(--fs-h2);
  font-weight: 900;
  line-height: 1.25;
  letter-spacing: -0.01em;
}

.page-about .ab-sec__lead {
  margin: 0 0 22px;
  max-width: 68ch;
  color: var(--dim);
  line-height: 1.78;
}

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

.page-about .ab-split__text {
  min-width: 0;
}

.page-about .prose p {
  margin: 0 0 1em;
  line-height: 1.78;
  color: var(--white);
}

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

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

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

.page-about .ab-inline-link {
  display: inline-block;
  margin-top: 14px;
  padding-bottom: 3px;
  font-size: 13px;
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid var(--grid);
  transition: border-color 0.16s ease;
}

.page-about .ab-inline-link:hover {
  border-bottom-color: var(--cyan);
}

/* ---------- 五条主线 ---------- */
.page-about .ab-pillars {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .ab-pillar {
  position: relative;
  padding: 18px 18px 20px;
  border: var(--line);
  background: var(--panel);
  transition: transform 0.18s ease, border-color 0.18s ease;
}

.page-about .ab-pillar:hover {
  transform: translateY(-2px);
  border-color: var(--cyan);
}

.page-about .ab-pillar__idx {
  display: inline-block;
  margin-bottom: 12px;
  padding: 2px 7px;
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--violet);
  border: 1px solid var(--grid);
}

.page-about .ab-pillar h3 {
  margin: 0 0 8px;
  font-size: var(--fs-h3);
  font-weight: 700;
}

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

/* ---------- 维护流程 ---------- */
.page-about .ab-flow {
  list-style: none;
  margin: 32px 0 0;
  padding: 0;
  display: grid;
  gap: 22px;
}

.page-about .ab-flow__step {
  position: relative;
  padding-top: 22px;
  border-top: 1px solid var(--grid);
}

.page-about .ab-flow__step::before {
  content: "";
  position: absolute;
  top: -3px;
  left: 0;
  width: 6px;
  height: 6px;
  background: var(--cyan);
}

.page-about .ab-flow__no {
  display: block;
  margin-bottom: 8px;
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--cyan);
}

.page-about .ab-flow__step h3 {
  margin: 0 0 6px;
  font-size: var(--fs-h3);
}

.page-about .ab-flow__step p {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--dim);
}

/* ---------- 协作网络图 ---------- */
.page-about .ab-net-wrap {
  margin: 26px 0 0;
  padding: 16px 12px 4px;
  border: var(--line);
  background: var(--panel);
}

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

.page-about .ab-net text {
  text-anchor: middle;
  font-family: var(--font-body);
  font-size: 13px;
  fill: var(--white);
}

.page-about .ab-net__spoke line {
  stroke: var(--grid);
  stroke-width: 1;
  transition: stroke 0.18s ease;
}

.page-about .ab-net__spoke rect {
  fill: var(--panel-2);
  stroke: var(--grid);
  stroke-width: 1;
  transition: stroke 0.18s ease, fill 0.18s ease;
}

.page-about .ab-net__spoke:hover line {
  stroke: var(--cyan);
}

.page-about .ab-net__spoke:hover rect {
  stroke: var(--cyan);
  fill: var(--panel);
}

.page-about .ab-net__core rect {
  fill: rgba(168, 85, 247, 0.14);
  stroke: var(--violet);
  stroke-width: 1;
}

.page-about .ab-net__core text {
  font-weight: 700;
}

.page-about .ab-net__cap {
  display: block;
  margin-top: 12px;
  padding: 10px 6px 12px;
  font-size: 12px;
  line-height: 1.7;
  color: var(--dim);
  border-top: 1px solid var(--grid);
}

.page-about .ab-facts {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .ab-facts li {
  padding: 14px 16px;
  font-size: 14px;
  line-height: 1.6;
  color: var(--dim);
  background: var(--panel);
  border: var(--line);
  border-left: 2px solid var(--violet);
}

.page-about .ab-facts .mono {
  display: block;
  margin-bottom: 4px;
  font-size: 20px;
  font-weight: 700;
  color: var(--white);
  letter-spacing: 0.01em;
}

/* ---------- 约战 ---------- */
.page-about .ab-squad {
  list-style: none;
  margin: 0;
  padding: 0;
  border: var(--line);
  background: var(--panel);
}

.page-about .ab-squad li {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  padding: 14px 16px;
  border-bottom: 1px solid var(--grid);
}

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

.page-about .ab-squad__k {
  flex: none;
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--cyan);
}

.page-about .ab-squad__v {
  font-size: 14px;
  text-align: right;
  color: var(--white);
}

/* ---------- 时间轴 ---------- */
.page-about .ab-timeline {
  position: relative;
  list-style: none;
  margin: 32px 0 0;
  padding: 0;
  display: grid;
  gap: 28px;
}

.page-about .ab-timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 6px;
  bottom: 6px;
  width: 1px;
  background: var(--grid);
}

.page-about .ab-timeline__node {
  position: relative;
  padding-left: 26px;
}

.page-about .ab-timeline__dot {
  position: absolute;
  left: 0;
  top: 4px;
  width: 11px;
  height: 11px;
  box-sizing: border-box;
  border: 1px solid var(--cyan);
  border-radius: 50%;
  background: var(--ink-900);
  transition: background 0.18s ease, box-shadow 0.18s ease;
}

.page-about .ab-timeline__phase {
  display: block;
  margin-bottom: 6px;
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--cyan);
}

.page-about .ab-timeline__node h3 {
  margin: 0 0 6px;
  font-size: 15px;
  font-weight: 700;
}

.page-about .ab-timeline__note {
  margin: 0;
  font-size: 13px;
  line-height: 1.72;
  color: var(--dim);
}

.page-about .ab-figure--wide {
  margin-top: 36px;
}

/* ---------- 加入我们 ---------- */
.page-about .ab-join {
  display: grid;
  gap: 12px;
}

.page-about .ab-join__card {
  padding: 20px;
  border: var(--line);
  background: var(--panel);
  transition: transform 0.18s ease, border-color 0.18s ease;
}

.page-about .ab-join__card:hover {
  transform: translateY(-2px);
  border-color: var(--violet);
}

.page-about .ab-join__card h3 {
  margin: 0 0 8px;
  font-size: var(--fs-h3);
}

.page-about .ab-join__card p {
  margin: 0;
  font-size: 14px;
  line-height: 1.72;
  color: var(--dim);
}

.page-about .ab-cta {
  display: grid;
  gap: 8px;
  margin-top: 24px;
  padding: 22px;
  border: 1px solid var(--grid);
  border-left: 3px solid var(--flare);
  background: linear-gradient(100deg, rgba(255, 90, 31, 0.09), transparent 58%), var(--panel);
}

.page-about .ab-cta__label {
  margin: 0;
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--flare);
}

.page-about .ab-cta__mail {
  margin: 0;
  font-size: clamp(1rem, 2.4vw, 1.35rem);
  color: var(--white);
  word-break: break-all;
}

.page-about .ab-cta__note {
  margin: 0 0 8px;
  max-width: 62ch;
  font-size: 14px;
  line-height: 1.72;
  color: var(--dim);
}

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

/* ---------- 中屏 ---------- */
@media (min-width: 620px) {
  .page-about .ab-facts {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 720px) {
  .page-about .ab-pillars {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .ab-pillar:last-child {
    grid-column: 1 / -1;
  }

  .page-about .ab-flow {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 26px;
  }

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

@media (min-width: 780px) {
  .page-about .ab-split {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.92fr);
    gap: 40px;
    align-items: start;
  }

  .page-about .ab-split--offset .ab-figure {
    margin-top: 44px;
  }

  .page-about .ab-split--flip {
    grid-template-columns: minmax(0, 0.92fr) minmax(0, 1.08fr);
  }

  .page-about .ab-split--flip .ab-figure {
    order: 1;
  }

  .page-about .ab-split--flip .ab-split__text {
    order: 2;
  }
}

/* ---------- 时间轴横向化 ---------- */
@media (min-width: 900px) {
  .page-about .ab-timeline {
    grid-template-columns: repeat(6, minmax(178px, 1fr));
    gap: 0 22px;
    overflow-x: auto;
    padding-bottom: 10px;
    scroll-snap-type: x proximity;
  }

  .page-about .ab-timeline::before {
    display: none;
  }

  .page-about .ab-timeline__node {
    padding-left: 0;
    padding-top: 30px;
    scroll-snap-align: start;
  }

  .page-about .ab-timeline__node::after {
    content: "";
    position: absolute;
    left: 0;
    right: -22px;
    top: 5px;
    height: 1px;
    background: var(--grid);
  }

  .page-about .ab-timeline__node:last-child::after {
    right: 0;
  }

  .page-about .ab-timeline__dot {
    left: 0;
    top: 0;
  }

  .page-about .ab-timeline__note {
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
  }

  .page-about .ab-timeline__node:hover .ab-timeline__note,
  .page-about .ab-timeline__node:focus-within .ab-timeline__note {
    -webkit-line-clamp: 12;
  }

  .page-about .ab-timeline__node:hover .ab-timeline__dot,
  .page-about .ab-timeline__node:focus-within .ab-timeline__dot {
    background: var(--cyan);
    box-shadow: 0 0 0 4px rgba(34, 224, 255, 0.16);
  }
}

/* ---------- 桌面双栏 ---------- */
@media (min-width: 1000px) {
  .page-about .ab-hero {
    padding-bottom: 72px;
  }

  .page-about .ab-hero__grid {
    grid-template-columns: minmax(0, 1.18fr) minmax(0, 0.82fr);
    gap: 56px;
    align-items: start;
  }

  .page-about .ab-terminal {
    margin-top: 38px;
  }

  .page-about .ab-body {
    grid-template-columns: var(--ab-toc-w) minmax(0, 1fr);
    gap: 60px;
    padding-top: 64px;
    padding-bottom: 96px;
  }

  .page-about .ab-toc {
    position: sticky;
    top: calc(var(--header-total) + 22px);
    align-self: start;
  }

  .page-about .ab-toc__title {
    display: block;
  }

  .page-about .ab-toc__list {
    display: block;
    overflow: visible;
    padding: 0;
  }

  .page-about .ab-toc__list li + li {
    margin-top: 2px;
  }

  .page-about .ab-toc__link {
    padding: 8px 0 8px 14px;
    border: 0;
    border-left: 2px solid var(--grid);
    background: transparent;
    white-space: normal;
    line-height: 1.5;
    transition: border-color 0.16s ease, color 0.16s ease;
  }

  .page-about .ab-toc__link:hover,
  .page-about .ab-toc__link:focus-visible {
    border-left-color: var(--cyan);
    color: var(--white);
  }

  .page-about .ab-sec {
    padding: 52px 0;
  }

  .page-about .ab-cta {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    column-gap: 32px;
  }

  .page-about .ab-cta__label {
    grid-column: 1 / -1;
  }

  .page-about .ab-cta__mail {
    grid-column: 1;
  }

  .page-about .ab-cta__note {
    grid-column: 1;
    margin-bottom: 0;
  }

  .page-about .ab-cta .btn {
    grid-column: 2;
    grid-row: 2 / span 2;
    align-self: center;
  }
}
<<<END>>>