.page-about {
  --ab-rail: 236px;
  --ab-gap: clamp(24px, 3.6vw, 56px);
  background-color: var(--ink);
  color: var(--fog);
}

.page-about .ab-top {
  border-bottom: 1px solid var(--line-soft);
  padding: 14px 0;
}

.page-about .crumbs a {
  color: var(--fog-62);
  text-decoration: none;
}

.page-about .crumbs a:hover,
.page-about .crumbs a:focus-visible {
  color: var(--cyan);
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(32px, 5vw, 64px) 0 clamp(40px, 6vw, 80px);
  border-bottom: 1px solid var(--line);
  background:
    radial-gradient(92% 118% at 88% 0%, rgba(52, 245, 225, 0.10), transparent 62%),
    radial-gradient(70% 92% at 4% 100%, rgba(155, 123, 255, 0.10), transparent 60%),
    var(--ink);
}

.page-about .ab-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  opacity: 0.26;
  background-image:
    repeating-linear-gradient(90deg, var(--line) 0 1px, transparent 1px 72px),
    repeating-linear-gradient(0deg, var(--line) 0 1px, transparent 1px 72px);
  -webkit-mask-image: linear-gradient(180deg, #000 0%, transparent 78%);
  mask-image: linear-gradient(180deg, #000 0%, transparent 78%);
}

.page-about .ab-hero__grid {
  position: relative;
  display: grid;
  gap: clamp(28px, 4vw, 44px);
  align-items: center;
}

.page-about .ab-hero h1 {
  margin: 14px 0 18px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(2rem, 5.6vw, 4rem);
  line-height: 1.14;
  letter-spacing: -0.01em;
  color: var(--fog);
}

.page-about .ab-hero__intro {
  max-width: 56ch;
  margin: 0;
  font-size: clamp(0.98rem, 1.2vw, 1.06rem);
  line-height: 1.85;
  color: var(--fog-80);
}

.page-about .ab-hero__stats {
  list-style: none;
  margin: clamp(22px, 3vw, 34px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  border: 1px solid var(--line-soft);
  background: var(--line-soft);
}

.page-about .ab-hero__stats li {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 14px 16px;
  background: var(--ink-2);
}

.page-about .ab-num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(1.5rem, 2.6vw, 2rem);
  font-weight: 700;
  line-height: 1;
  color: var(--cyan);
}

.page-about .ab-lbl {
  font-size: 0.76rem;
  letter-spacing: 0.02em;
  color: var(--fog-62);
}

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

.page-about .ab-hero__fig {
  margin: 0;
  border: 1px solid var(--line);
  background: linear-gradient(150deg, rgba(63, 216, 255, 0.18), rgba(155, 123, 255, 0.08) 52%, transparent);
}

/* ---------- 主体骨架 ---------- */
.page-about .ab-layout {
  display: grid;
  gap: 28px;
  min-width: 0;
  padding-top: clamp(36px, 5vw, 68px);
  padding-bottom: clamp(48px, 7vw, 96px);
}

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

/* ---------- 章节目录 ---------- */
.page-about .ab-toc {
  border-left: 1px solid var(--line);
  padding-left: 16px;
}

.page-about .ab-toc__title {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.2em;
  color: var(--fog-38);
}

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

.page-about .ab-toc__link {
  position: relative;
  display: flex;
  align-items: baseline;
  gap: 9px;
  padding: 9px 0;
  font-size: 0.86rem;
  white-space: nowrap;
  text-decoration: none;
  color: var(--fog-62);
  transition: color 0.2s ease;
}

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

.page-about .ab-toc__link.is-current,
.page-about .ab-toc__link[aria-current="true"] {
  color: var(--cyan);
}

.page-about .ab-toc__num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 0.72rem;
  color: var(--fog-38);
}

/* ---------- 章节 ---------- */
.page-about .ab-section {
  margin-top: clamp(36px, 5vw, 60px);
  padding-top: clamp(32px, 4.5vw, 56px);
  border-top: 1px solid var(--line);
  scroll-margin-top: calc(var(--header-h) + 24px);
}

.page-about .ab-section:first-child {
  margin-top: 0;
  padding-top: 0;
  border-top: 0;
}

.page-about .ab-section h2 {
  margin: 10px 0 20px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.55rem, 3.2vw, 2.35rem);
  line-height: 1.24;
  color: var(--fog);
}

.page-about .ab-section .prose {
  max-width: 68ch;
  margin: 0 0 16px;
  font-size: 1rem;
  line-height: 1.85;
  color: var(--fog-80);
}

.page-about .ab-more {
  max-width: 68ch;
  margin: 20px 0 0;
  font-size: 0.92rem;
  line-height: 1.8;
  color: var(--fog-62);
}

.page-about .ab-more a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(52, 245, 225, 0.4);
}

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

.page-about .ab-fig {
  margin: clamp(24px, 3.4vw, 36px) 0 0;
  border: 1px solid var(--line);
  background: linear-gradient(160deg, rgba(63, 216, 255, 0.12), rgba(155, 123, 255, 0.08) 60%, transparent);
}

.page-about .ab-fig--narrow {
  max-width: 420px;
}

/* ---------- 时间轴 ---------- */
.page-about .ab-timeline {
  position: relative;
  margin: clamp(24px, 3.4vw, 36px) 0 0;
  padding-left: 26px;
}

.page-about .ab-timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 10px;
  bottom: 10px;
  width: 1px;
  background: linear-gradient(180deg, var(--cyan) 0%, var(--line) 32%, var(--line) 100%);
}

.page-about .ab-stage {
  position: relative;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .ab-stage::before {
  content: "";
  position: absolute;
  left: -26px;
  top: 19px;
  width: 11px;
  height: 11px;
  border: 1px solid var(--line);
  background: var(--ink);
  transform: rotate(45deg);
  transition: background 0.2s ease, border-color 0.2s ease;
}

.page-about .ab-stage[open]::before {
  background: var(--cyan);
  border-color: var(--cyan);
}

.page-about .ab-stage > summary {
  list-style: none;
  cursor: pointer;
  display: grid;
  grid-template-columns: 4.2rem minmax(0, 1fr) 14px;
  align-items: center;
  gap: 12px;
  padding: 15px 2px;
}

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

.page-about .ab-stage > summary:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
}

.page-about .ab-stage__year {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 0.78rem;
  letter-spacing: 0.04em;
  color: var(--orange);
}

.page-about .ab-stage__title {
  font-size: 0.96rem;
  font-weight: 600;
  color: var(--fog);
}

.page-about .ab-stage__chev {
  justify-self: end;
  width: 8px;
  height: 8px;
  border-right: 1px solid var(--fog-62);
  border-bottom: 1px solid var(--fog-62);
  transform: rotate(45deg);
  transition: transform 0.22s ease;
}

.page-about .ab-stage[open] .ab-stage__chev {
  transform: rotate(225deg);
}

.page-about .ab-stage__body {
  padding: 0 2px 18px 4.4rem;
  font-size: 0.9rem;
  line-height: 1.8;
  color: var(--fog-62);
}

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

/* ---------- 团队关系图 ---------- */
.page-about .ab-tree {
  margin-top: clamp(24px, 3.4vw, 36px);
  padding: clamp(18px, 3vw, 28px);
  border: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(27, 53, 80, 0.55), rgba(11, 34, 57, 0.72));
}

.page-about .ab-tree__root {
  position: relative;
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  margin-bottom: 26px;
  padding: 9px 16px;
  border: 1px solid var(--cyan);
  font-size: 0.88rem;
  color: var(--fog);
}

.page-about .ab-tree__count {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--cyan);
}

.page-about .ab-tree__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .ab-tree__node {
  display: flex;
  flex-direction: column;
  gap: 9px;
  padding: 16px;
  border: 1px solid var(--line);
  border-top: 2px solid var(--cyan);
  background: var(--ink);
}

.page-about .ab-tree__node:nth-child(2) {
  border-top-color: var(--violet);
}

.page-about .ab-tree__node:nth-child(3) {
  border-top-color: var(--mint);
}

.page-about .ab-tree__node h3 {
  margin: 0;
  font-family: var(--font-ui);
  font-size: 1rem;
  font-weight: 700;
  color: var(--fog);
}

.page-about .ab-tree__node p {
  margin: 0;
  font-size: 0.88rem;
  line-height: 1.78;
  color: var(--fog-62);
}

.page-about .ab-tree__node .tag {
  align-self: flex-start;
}

/* ---------- 双版本 ---------- */
.page-about .ab-versions {
  display: grid;
  gap: 14px;
  margin-top: clamp(24px, 3.4vw, 34px);
}

.page-about .ab-version {
  padding: 20px;
  border: 1px solid var(--line);
  background: var(--ink-2);
  border-top: 2px solid var(--cyan);
}

.page-about .ab-version--beta {
  border-top-color: var(--orange);
}

.page-about .ab-version__kicker {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  color: var(--fog-38);
}

.page-about .ab-version h3 {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--fog);
}

.page-about .ab-version > p {
  margin: 0 0 14px;
  font-size: 0.9rem;
  line-height: 1.8;
  color: var(--fog-62);
}

.page-about .ab-version__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 8px;
}

.page-about .ab-version__list li {
  position: relative;
  padding-left: 16px;
  font-size: 0.86rem;
  line-height: 1.7;
  color: var(--fog-80);
}

.page-about .ab-version__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.62em;
  width: 7px;
  height: 1px;
  background: var(--cyan);
}

.page-about .ab-version--beta .ab-version__list li::before {
  background: var(--orange);
}

.page-about .ab-records {
  list-style: none;
  margin: 18px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(118px, 1fr));
  gap: 1px;
  border: 1px solid var(--line-soft);
  background: var(--line-soft);
}

.page-about .ab-records li {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 14px;
  background: var(--ink-2);
}

.page-about .ab-records__v {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 1.3rem;
  font-weight: 700;
  line-height: 1;
  color: var(--mint);
}

.page-about .ab-records__k {
  font-size: 0.76rem;
  line-height: 1.5;
  color: var(--fog-62);
}

/* ---------- 更新节奏 ---------- */
.page-about .ab-rhythm {
  list-style: none;
  margin: clamp(24px, 3.4vw, 34px) 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  border: 1px solid var(--line-soft);
  background: var(--line-soft);
}

.page-about .ab-rhythm__item {
  display: grid;
  gap: 8px;
  padding: 18px clamp(16px, 3vw, 24px);
  background: var(--ink-2);
}

.page-about .ab-rhythm__time {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 0.8rem;
  letter-spacing: 0.04em;
  color: var(--cyan);
}

.page-about .ab-rhythm__text h3 {
  margin: 0 0 6px;
  font-family: var(--font-ui);
  font-size: 0.98rem;
  font-weight: 700;
  color: var(--fog);
}

.page-about .ab-rhythm__text p {
  margin: 0;
  font-size: 0.89rem;
  line-height: 1.78;
  color: var(--fog-62);
}

/* ---------- 合作生态 ---------- */
.page-about .ab-partners__track {
  list-style: none;
  margin: clamp(24px, 3.4vw, 34px) 0 0;
  padding: 0 0 12px;
  display: flex;
  gap: 14px;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  scrollbar-width: thin;
}

.page-about .ab-partners__card {
  flex: 0 0 clamp(220px, 74vw, 300px);
  scroll-snap-align: start;
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 20px;
  border: 1px solid var(--line);
  border-left: 2px solid var(--violet);
  background: var(--ink-2);
}

.page-about .ab-partners__n {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 1.6rem;
  font-weight: 700;
  line-height: 1;
  color: var(--violet);
}

.page-about .ab-partners__card h3 {
  margin: 0;
  font-family: var(--font-ui);
  font-size: 0.98rem;
  font-weight: 700;
  color: var(--fog);
}

.page-about .ab-partners__card p {
  margin: 0;
  font-size: 0.86rem;
  line-height: 1.78;
  color: var(--fog-62);
}

/* ---------- 服务与联系 ---------- */
.page-about .ab-facts {
  margin: clamp(22px, 3vw, 30px) 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  border: 1px solid var(--line-soft);
  background: var(--line-soft);
}

.page-about .ab-facts__row {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 6px 16px;
  padding: 12px 16px;
  background: var(--ink-2);
}

.page-about .ab-facts__row dt {
  min-width: 76px;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  color: var(--fog-38);
}

.page-about .ab-facts__row dd {
  margin: 0;
  font-size: 0.91rem;
  line-height: 1.7;
  color: var(--fog);
  word-break: break-word;
}

/* ---------- 响应式 ---------- */
@media (min-width: 620px) {
  .page-about .ab-stage > summary {
    grid-template-columns: 5.4rem minmax(0, 1fr) 16px;
    gap: 16px;
  }

  .page-about .ab-stage__body {
    padding-left: 5.6rem;
  }
}

@media (min-width: 720px) {
  .page-about .ab-hero__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

  .page-about .ab-rhythm__item {
    grid-template-columns: 128px minmax(0, 1fr);
    align-items: start;
    gap: 22px;
  }

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

@media (min-width: 760px) {
  .page-about .ab-tree__list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 16px;
  }
}

@media (min-width: 900px) {
  .page-about .ab-hero__grid {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.92fr);
  }
}

@media (min-width: 980px) {
  .page-about .ab-layout {
    grid-template-columns: var(--ab-rail) minmax(0, 1fr);
    gap: var(--ab-gap);
    align-items: start;
  }

  .page-about .ab-rail {
    position: sticky;
    top: calc(var(--header-h) + 28px);
    align-self: start;
  }

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

  .page-about .ab-toc__link {
    padding: 9px 0;
  }

  .page-about .ab-toc__link::before {
    content: "";
    position: absolute;
    left: -17px;
    top: 50%;
    width: 2px;
    height: 16px;
    background: var(--cyan);
    transform: translateY(-50%) scaleY(0);
    transform-origin: center;
    transition: transform 0.25s ease;
  }

  .page-about .ab-toc__link.is-current::before,
  .page-about .ab-toc__link[aria-current="true"]::before {
    transform: translateY(-50%) scaleY(1);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-stage::before,
  .page-about .ab-stage__chev,
  .page-about .ab-toc__link,
  .page-about .ab-toc__link::before {
    transition: none;
  }
}
<<<END>>>