.page-about {
  --ab-rail-w: 224px;
  --ab-flow-gap: 56px;
  --ab-sec-gap: 40px;
  color: var(--text-body);
  padding-bottom: 24px;
}

/* ---------- 面包屑与页头 ---------- */
.page-about .breadcrumb {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 20px 0 0;
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--muted);
}
.page-about .breadcrumb a {
  color: var(--muted);
  text-decoration: none;
}
.page-about .breadcrumb a:hover { color: var(--data); }
.page-about .breadcrumb [aria-current="page"] { color: var(--text-body); }

.page-about .ab-masthead {
  position: relative;
  display: grid;
  gap: 26px;
  padding: 30px 0 44px;
  border-bottom: 1px solid var(--line);
}
.page-about .ab-masthead-main {
  display: grid;
  gap: 16px;
}
.page-about .ab-masthead h1 {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(30px, 5.6vw, 54px);
  line-height: 1.12;
  letter-spacing: -0.02em;
  color: var(--paper);
  max-width: 15ch;
}
.page-about .ab-masthead .lead {
  margin: 0;
  max-width: 40em;
  font-size: 16px;
  line-height: 1.8;
  color: var(--text-body);
}

.page-about .ab-vlabel {
  display: none;
}

.page-about .ab-facts {
  display: flex;
  flex-wrap: wrap;
  gap: 14px 34px;
  margin: 4px 0 0;
  padding: 0;
  list-style: none;
}
.page-about .ab-facts li {
  display: flex;
  align-items: baseline;
  gap: 9px;
  font-size: 13px;
  color: var(--muted);
}
.page-about .ab-fact-num {
  font-size: 20px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--data);
}

/* ---------- 主布局 ---------- */
.page-about .ab-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 32px;
  padding-top: 36px;
  padding-bottom: 72px;
}

/* ---------- 左侧索引 ---------- */
.page-about .ab-rail {
  align-self: start;
  min-width: 0;
}
.page-about .ab-rail-title {
  margin: 0 0 12px;
  font-size: 12px;
  letter-spacing: 0.28em;
  color: var(--muted);
}
.page-about .ab-rail-list {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 0 0 6px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: none;
}
.page-about .ab-rail-list::-webkit-scrollbar { display: none; }

.page-about .ab-rail-link {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 8px 14px;
  border: 1px solid var(--line);
  border-radius: 999px;
  white-space: nowrap;
  text-decoration: none;
  color: var(--muted);
  transition: color 160ms var(--ease), border-color 160ms var(--ease), background 160ms var(--ease);
}
.page-about .ab-rail-year {
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--muted);
  transition: color 160ms var(--ease);
}
.page-about .ab-rail-cap { font-size: 12px; }

.page-about .ab-rail-link:hover,
.page-about .ab-rail-link[aria-current="true"] {
  color: var(--paper);
  border-color: var(--ink-600);
  background: var(--ink-800);
}
.page-about .ab-rail-link:hover .ab-rail-year,
.page-about .ab-rail-link[aria-current="true"] .ab-rail-year {
  color: var(--yellow);
}

/* ---------- 章节 ---------- */
.page-about .ab-flow {
  min-width: 0;
  display: flex;
  flex-direction: column;
}
.page-about .ab-sec {
  padding: 0 0 64px;
  border-top: 1px solid var(--line);
  padding-top: 40px;
  scroll-margin-top: calc(var(--header-h) + 20px);
}
.page-about .ab-sec:first-child {
  border-top: 0;
  padding-top: 0;
}
.page-about .ab-sec:last-child {
  padding-bottom: 16px;
}

.page-about .ab-sec-head {
  display: flex;
  align-items: baseline;
  gap: 14px;
  flex-wrap: wrap;
  margin-bottom: 18px;
}
.page-about .ab-sec-no {
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.24em;
  color: var(--data);
}
.page-about .ab-sec-head .h2 {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(22px, 3.4vw, 32px);
  line-height: 1.25;
  letter-spacing: -0.02em;
  color: var(--paper);
}
.page-about .ab-sec-intro {
  margin: 0 0 26px;
  max-width: 40em;
  font-size: 15px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .ab-prose p {
  margin: 0 0 16px;
  max-width: 40em;
  font-size: 16px;
  line-height: 1.8;
  color: var(--text-body);
}
.page-about .ab-prose p:last-child { margin-bottom: 0; }

.page-about .ab-inline-link { margin-top: 6px !important; }
.page-about .ab-inline-link a {
  color: var(--data);
  text-decoration: none;
  border-bottom: 1px solid rgba(77, 163, 255, 0.4);
  padding-bottom: 1px;
  transition: border-color 160ms var(--ease);
}
.page-about .ab-inline-link a:hover { border-bottom-color: var(--data); }

.page-about a:focus-visible,
.page-about .tag:focus-visible {
  outline: 2px solid var(--yellow);
  outline-offset: 2px;
}

/* ---------- 图文分栏 ---------- */
.page-about .ab-split {
  display: grid;
  gap: 26px;
}

.page-about .ab-fig,
.page-about .ab-fig-plate {
  margin: 0;
  overflow: hidden;
}
.page-about .ab-fig img,
.page-about .ab-fig-plate img,
.page-about .ab-history-fig img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  filter: saturate(0.82);
}
.page-about .ab-fig-plate {
  margin-top: 26px;
}

/* ---------- 时间线 ---------- */
.page-about .ab-history {
  display: grid;
  gap: 30px;
}
.page-about .ab-timeline {
  list-style: none;
  margin: 0;
  padding: 0 0 0 4px;
}
.page-about .ab-node {
  position: relative;
  padding: 0 0 36px 28px;
  border-left: 1px solid var(--line);
  scroll-margin-top: calc(var(--header-h) + 24px);
}
.page-about .ab-node:first-child { padding-top: 4px; }
.page-about .ab-node:last-child { padding-bottom: 8px; border-left-color: transparent; }

.page-about .ab-node::before {
  content: "";
  position: absolute;
  left: -5px;
  top: 12px;
  width: 9px;
  height: 9px;
  background: var(--ink-900);
  border: 1px solid var(--ink-600);
  transition: background 160ms var(--ease), border-color 160ms var(--ease);
}
.page-about .ab-node:first-child::before { top: 16px; }
.page-about .ab-node:hover::before {
  background: var(--data);
  border-color: var(--data);
}

.page-about .ab-node-head {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 8px;
}
.page-about .ab-node-year {
  font-size: 22px;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--data);
}
.page-about .ab-node .h3 {
  margin: 0 0 8px;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: 18px;
  line-height: 1.4;
  color: var(--paper);
}
.page-about .ab-node p {
  margin: 0;
  max-width: 38em;
  font-size: 15px;
  line-height: 1.8;
  color: var(--text-body);
}

.page-about .ab-history-fig { margin: 0; }

/* ---------- 档案卡 ---------- */
.page-about .ab-files {
  display: grid;
  gap: 8px;
}
.page-about .ab-file {
  background: var(--ink-800);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px 20px 24px;
  transition: transform 160ms var(--ease), border-color 160ms var(--ease), background 160ms var(--ease);
}
.page-about .ab-file:hover {
  transform: translateY(-2px);
  border-color: var(--ink-600);
  background: var(--ink-700);
}
.page-about .ab-file-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 14px;
}
.page-about .ab-file-num {
  font-size: 26px;
  font-weight: 700;
  letter-spacing: 0.03em;
  color: var(--data);
}
.page-about .ab-file-unit {
  font-family: var(--font-body);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--muted);
  margin-left: 4px;
}
.page-about .ab-file .h3 {
  margin: 0 0 10px;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: 18px;
  color: var(--paper);
}
.page-about .ab-file p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--text-body);
}

/* ---------- 合作 ---------- */
.page-about .ab-partner {
  display: grid;
  gap: 26px;
}
.page-about .ab-partner-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 8px;
}
.page-about .ab-partner-list li {
  display: grid;
  grid-template-columns: 10px minmax(0, 1fr);
  gap: 4px 12px;
  align-items: start;
  padding: 16px 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--ink-800);
  font-size: 14px;
  line-height: 1.75;
  transition: border-color 160ms var(--ease);
}
.page-about .ab-partner-list li:hover { border-color: var(--ink-600); }
.page-about .ab-partner-list .dot {
  margin-top: 8px;
  grid-row: 1 / span 2;
}
.page-about .ab-partner-list strong {
  font-weight: 700;
  color: var(--paper);
}
.page-about .ab-partner-list span:last-child {
  grid-column: 2;
  color: var(--muted);
}

/* ---------- 节奏与联系 ---------- */
.page-about .ab-cadence {
  list-style: none;
  margin: 0 0 32px;
  padding: 0;
  display: grid;
  gap: 0;
  border-top: 1px solid var(--line);
}
.page-about .ab-cadence li {
  display: grid;
  gap: 8px;
  padding: 20px 0;
  border-bottom: 1px solid var(--line);
}
.page-about .ab-cadence-key {
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: var(--yellow);
}
.page-about .ab-cadence p {
  margin: 0;
  max-width: 40em;
  font-size: 15px;
  line-height: 1.8;
  color: var(--text-body);
}

.page-about .ab-contact {
  padding: 22px 20px 24px;
  background: var(--ink-800);
  border: 1px solid var(--line);
  border-left: 2px solid var(--data);
  border-radius: var(--radius);
}
.page-about .ab-contact-title {
  margin: 0 0 16px;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: 16px;
  color: var(--paper);
}
.page-about .ab-contact-list {
  list-style: none;
  margin: 0 0 16px;
  padding: 0;
  display: grid;
  gap: 10px;
}
.page-about .ab-contact-list li {
  display: grid;
  grid-template-columns: 74px minmax(0, 1fr);
  gap: 10px;
  align-items: baseline;
  font-size: 14px;
}
.page-about .ab-contact-list .contact-label {
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--muted);
}
.page-about .ab-contact-list .contact-value-text {
  font-family: var(--font-mono);
  color: var(--paper);
  word-break: break-word;
}
.page-about .ab-contact-note {
  margin: 0;
  font-size: 13px;
  line-height: 1.8;
  color: var(--muted);
}

/* ---------- 出口卡片 ---------- */
.page-about .ab-sec-next { padding-bottom: 0; }
.page-about .ab-next {
  display: grid;
  gap: 8px;
}
.page-about .ab-next-card {
  display: grid;
  gap: 6px;
  padding: 20px 18px;
  background: var(--ink-800);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  text-decoration: none;
  transition: transform 160ms var(--ease), border-color 160ms var(--ease), background 160ms var(--ease);
}
.page-about .ab-next-card:hover {
  transform: translateY(-2px);
  border-color: var(--ink-600);
  background: var(--ink-700);
}
.page-about .ab-next-idx {
  font-size: 12px;
  letter-spacing: 0.24em;
  color: var(--data);
}
.page-about .ab-next-title {
  font-family: var(--font-head);
  font-weight: 800;
  font-size: 17px;
  color: var(--paper);
}
.page-about .ab-next-desc {
  font-size: 13px;
  line-height: 1.75;
  color: var(--muted);
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .ab-cadence li {
    grid-template-columns: 168px minmax(0, 1fr);
    align-items: baseline;
    gap: 20px;
  }
  .page-about .ab-files {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .ab-next {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 860px) {
  .page-about .ab-split {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.05fr);
    align-items: start;
    gap: 40px;
  }
  .page-about .ab-masthead {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: start;
  }
  .page-about .ab-masthead-main { grid-column: 1; }
  .page-about .ab-vlabel {
    display: block;
    grid-column: 2;
    grid-row: 1;
    writing-mode: vertical-rl;
    font-size: 12px;
    letter-spacing: 0.36em;
    color: var(--muted);
    padding-top: 6px;
  }
  .page-about .ab-facts { grid-column: 1 / -1; }
  .page-about .ab-partner {
    grid-template-columns: minmax(0, 1fr) minmax(0, 0.95fr);
    align-items: start;
    gap: 40px;
  }
}

@media (min-width: 1000px) {
  .page-about .ab-layout {
    grid-template-columns: var(--ab-rail-w) minmax(0, 1fr);
    gap: var(--ab-flow-gap);
    padding-top: 48px;
  }
  .page-about .ab-rail {
    position: sticky;
    top: calc(var(--header-h) + 28px);
  }
  .page-about .ab-rail-list {
    flex-direction: column;
    gap: 0;
    overflow: visible;
  }
  .page-about .ab-rail-link {
    border: 0;
    border-left: 2px solid var(--line);
    border-radius: 0;
    padding: 9px 0 9px 14px;
    background: none;
  }
  .page-about .ab-rail-link:hover,
  .page-about .ab-rail-link[aria-current="true"] {
    background: none;
    border-left-color: var(--yellow);
    border-top-color: transparent;
    border-right-color: transparent;
    border-bottom-color: transparent;
  }
  .page-about .ab-history {
    grid-template-columns: minmax(0, 1fr) 300px;
    gap: 44px;
    align-items: start;
  }
  .page-about .ab-history-fig {
    position: sticky;
    top: calc(var(--header-h) + 32px);
  }
  .page-about .ab-next {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (prefers-reduced-motion: no-preference) {
  .page-about [data-reveal] {
    transform: translateY(6px);
    transition: transform 420ms var(--ease);
  }
  .page-about [data-reveal][data-revealed="true"] {
    transform: none;
  }
}
<<<END>>>