.page-about {
  --ab-gap: clamp(20px, 4vw, 48px);
  --ab-card-pad: clamp(16px, 2.4vw, 26px);
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  position: relative;
  padding-top: clamp(18px, 3vw, 32px);
}

.page-about .ab-hero::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 360px;
  background-image:
    linear-gradient(rgba(28, 74, 60, 0.6) 1px, transparent 1px),
    linear-gradient(90deg, rgba(28, 74, 60, 0.6) 1px, transparent 1px);
  background-size: 44px 44px;
  -webkit-mask-image: linear-gradient(to bottom, #000, transparent);
  mask-image: linear-gradient(to bottom, #000, transparent);
  pointer-events: none;
  z-index: 0;
}

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

.page-about .ab-hero__grid {
  display: grid;
  gap: var(--ab-gap);
  align-items: end;
}

.page-about .ab-hero__copy h1 {
  margin: 12px 0 0;
  font-family: var(--font-serif);
  font-weight: 900;
  font-size: clamp(30px, 6vw, 58px);
  line-height: 1.14;
  letter-spacing: -0.02em;
  color: var(--paper);
}

.page-about .ab-hero__lead {
  margin: 18px 0 0;
  max-width: 56ch;
  font-size: clamp(15px, 1.4vw, 17px);
  line-height: 1.85;
  color: var(--body-text);
}

.page-about .ab-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

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

/* ---------- 数字带 ---------- */
.page-about .ab-figures {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(30px, 5vw, 56px) 0 0;
  padding: 0;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .ab-figure {
  background: var(--panel);
  padding: 16px 16px 18px;
}

.page-about .ab-figure dt {
  font-size: clamp(20px, 2.6vw, 28px);
  color: var(--amber);
  letter-spacing: 0.02em;
}

.page-about .ab-figure dd {
  margin: 8px 0 0;
  font-size: 13px;
  line-height: 1.6;
  color: var(--mist);
}

/* ---------- 通用章节头 ---------- */
.page-about .ab-head {
  display: grid;
  gap: 14px;
  margin-bottom: clamp(22px, 3vw, 36px);
}

.page-about .ab-head h2 {
  margin: 6px 0 0;
  font-family: var(--font-serif);
  font-weight: 800;
  font-size: clamp(24px, 3.6vw, 40px);
  line-height: 1.22;
  letter-spacing: -0.02em;
  color: var(--paper);
}

.page-about .ab-head__intro {
  margin: 14px 0 0;
  max-width: 68ch;
  font-size: 16px;
  line-height: 1.8;
  color: var(--body-text);
}

.page-about .sec-index {
  font-size: 38px;
  line-height: 1;
  color: var(--line);
  letter-spacing: 0.04em;
}

/* ---------- 时间轴 ---------- */
.page-about .ab-timeline {
  overflow-x: auto;
  padding-bottom: 14px;
  scroll-snap-type: x proximity;
  -webkit-overflow-scrolling: touch;
}

.page-about .ab-timeline__list {
  display: grid;
  grid-auto-flow: column;
  grid-auto-columns: minmax(min(250px, 78vw), 1fr);
  gap: 14px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .timeline-node {
  position: relative;
  display: flex;
  flex-direction: column;
  padding: 20px 18px 18px;
  background: var(--panel);
  border: 1px solid var(--line);
  scroll-snap-align: start;
}

.page-about .timeline-node::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  width: 2px;
  background: var(--cyan);
}

.page-about .timeline-date {
  margin: 0;
  font-size: 15px;
  letter-spacing: 0.1em;
  color: var(--amber);
}

.page-about .timeline-title {
  margin: 10px 0 0;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 19px;
  line-height: 1.4;
  color: var(--paper);
}

.page-about .timeline-node > p:not(.timeline-date):not(.timeline-title) {
  margin: 10px 0 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--body-text);
}

.page-about .ab-node {
  margin-top: auto;
  padding-top: 14px;
}

.page-about .ab-node .disclosure-toggle {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--cyan);
  background: none;
  border: 1px solid var(--line);
  padding: 7px 12px;
  cursor: pointer;
  transition: border-color 160ms ease, color 160ms ease;
}

.page-about .ab-node .disclosure-toggle:hover {
  border-color: var(--cyan);
  color: var(--amber-hi);
}

.page-about .ab-node .disclosure-panel {
  margin-top: 12px;
  font-size: 13.5px;
  line-height: 1.75;
  color: var(--mist);
  border-left: 1px solid var(--line);
  padding-left: 12px;
}

/* ---------- 档案室 ---------- */
.page-about .ab-room__grid {
  display: grid;
  gap: var(--ab-gap);
}

.page-about .ab-room__intro h2 {
  margin: 6px 0 0;
  font-family: var(--font-serif);
  font-weight: 800;
  font-size: clamp(24px, 3.6vw, 38px);
  line-height: 1.22;
  letter-spacing: -0.02em;
  color: var(--paper);
}

.page-about .ab-room__intro p {
  margin: 16px 0 0;
  font-size: 16px;
  line-height: 1.85;
  color: var(--body-text);
}

.page-about .ab-room__panels {
  display: grid;
  gap: 14px;
}

.page-about .ab-room__panel {
  padding: var(--ab-card-pad);
}

.page-about .ab-room__key {
  margin: 0;
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--cyan);
}

.page-about .ab-room__panel h3 {
  margin: 10px 0 0;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 20px;
  line-height: 1.4;
  color: var(--paper);
}

.page-about .ab-room__panel p:last-child {
  margin: 10px 0 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--body-text);
}

/* ---------- 体系 ---------- */
.page-about .ab-system__grid {
  display: grid;
  gap: var(--ab-gap);
  align-items: start;
}

.page-about .ab-system__ladder {
  border: 1px solid var(--line);
  background: var(--panel);
  padding: var(--ab-card-pad);
}

.page-about .ab-system__label {
  margin: 0 0 14px;
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--mist);
}

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

.page-about .ab-ladder rect:nth-of-type(-n+3) { fill: var(--line); }
.page-about .ab-ladder rect:nth-of-type(n+4):nth-of-type(-n+6) { fill: var(--mist); }
.page-about .ab-ladder rect:nth-of-type(n+7):nth-of-type(-n+8) { fill: var(--amber); }
.page-about .ab-ladder rect:nth-of-type(9) { fill: var(--cyan); }

.page-about .ab-ladder__labels text {
  font-family: var(--font-sans);
  font-size: 12px;
  fill: var(--mist);
  text-anchor: middle;
}

.page-about .ab-system__note {
  margin: 16px 0 0;
  font-size: 13.5px;
  line-height: 1.75;
  color: var(--mist);
}

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

/* ---------- 房间分类筛选 ---------- */
.page-about .ab-rooms {
  margin-top: clamp(28px, 4vw, 48px);
}

.page-about .ab-rooms__label {
  margin: 0 0 14px;
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--mist);
}

.page-about .ab-rooms__bar {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
  margin-bottom: 18px;
}

.page-about .ab-rooms__list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(240px, 100%), 1fr));
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .ab-room-card {
  background: var(--ink);
  padding: 18px 16px 20px;
  transition: background-color 180ms ease;
}

.page-about .ab-room-card:hover {
  background: var(--panel);
}

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

.page-about .ab-room-card h3 {
  margin: 10px 0 0;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 18px;
  line-height: 1.4;
  color: var(--paper);
}

.page-about .ab-room-card p:last-child {
  margin: 8px 0 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--body-text);
}

.page-about .ab-room-card.is-filtered {
  display: none;
}

.page-about .ab-room-card.filter-item-in {
  animation: abFadeIn 200ms ease both;
}

@keyframes abFadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ---------- 团队 ---------- */
.page-about .ab-team__grid {
  align-items: start;
}

.page-about .ab-team__media {
  margin: 0 0 22px;
}

.page-about .ab-team__copy h2 {
  margin: 6px 0 0;
  font-family: var(--font-serif);
  font-weight: 800;
  font-size: clamp(23px, 3.4vw, 36px);
  line-height: 1.24;
  letter-spacing: -0.02em;
  color: var(--paper);
}

.page-about .ab-team__copy > p {
  margin: 16px 0 0;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--body-text);
}

.page-about .ab-team__list {
  display: grid;
  gap: 1px;
  margin: 22px 0 0;
  padding: 0;
  list-style: none;
  background: var(--line);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.page-about .ab-team__list li {
  display: grid;
  gap: 4px;
  background: var(--ink);
  padding: 14px 14px 16px;
}

.page-about .ab-team__key {
  margin: 0;
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--amber);
}

.page-about .ab-team__list li p:last-child {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--body-text);
}

.page-about .ab-team__note {
  margin: 20px 0 0;
  padding-left: 14px;
  border-left: 2px solid var(--cyan);
  font-size: 14px;
  line-height: 1.75;
  color: var(--mist);
}

/* ---------- 服务覆盖 ---------- */
.page-about .ab-reach h2 {
  margin: 6px 0 0;
  font-family: var(--font-serif);
  font-weight: 800;
  font-size: clamp(23px, 3.4vw, 36px);
  line-height: 1.24;
  letter-spacing: -0.02em;
  color: var(--paper);
}

.page-about .ab-reach__grid {
  display: grid;
  gap: 14px;
  margin-top: clamp(22px, 3vw, 34px);
}

.page-about .ab-reach__panel {
  padding: var(--ab-card-pad);
}

.page-about .ab-reach__key {
  margin: 0;
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--cyan);
}

.page-about .ab-reach__panel h3 {
  margin: 10px 0 0;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 20px;
  line-height: 1.42;
  color: var(--paper);
}

.page-about .ab-reach__panel > p:last-child {
  margin: 10px 0 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--body-text);
}

.page-about .ab-reach__contact {
  margin: 14px 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 10px;
}

.page-about .ab-reach__contact li {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px;
}

.page-about .ab-reach__ck {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.14em;
  color: var(--mist);
}

.page-about .ab-reach__hint {
  margin: 14px 0 0;
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--mist);
}

/* ---------- 结尾引导 ---------- */
.page-about .ab-next__panel {
  display: grid;
  gap: 22px;
  padding: clamp(22px, 3.4vw, 40px);
}

.page-about .ab-next__copy h2 {
  margin: 6px 0 0;
  font-family: var(--font-serif);
  font-weight: 800;
  font-size: clamp(22px, 3vw, 32px);
  line-height: 1.26;
  letter-spacing: -0.02em;
  color: var(--paper);
}

.page-about .ab-next__copy p {
  margin: 12px 0 0;
  max-width: 60ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--body-text);
}

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

/* ---------- 平板 ---------- */
@media (min-width: 720px) {
  .page-about .ab-head {
    grid-template-columns: auto minmax(0, 1fr);
    gap: 22px;
    align-items: start;
  }

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

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

  .page-about .ab-teams__list li {
    grid-template-columns: 150px minmax(0, 1fr);
    align-items: baseline;
  }

  .page-about .ab-team__list li {
    grid-template-columns: 150px minmax(0, 1fr);
    align-items: baseline;
  }

  .page-about .ab-next__panel {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
  }

  .page-about .ab-next__actions {
    justify-content: flex-end;
  }
}

/* ---------- 桌面 ---------- */
@media (min-width: 960px) {
  .page-about .ab-hero__grid {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    gap: clamp(30px, 5vw, 64px);
  }

  .page-about .ab-room__grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: clamp(30px, 4.5vw, 60px);
  }

  .page-about .ab-system__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: clamp(28px, 4vw, 52px);
  }

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

  .page-about .ab-timeline__list {
    grid-auto-columns: minmax(0, 1fr);
  }

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

/* ---------- 减弱动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .ab-room-card.filter-item-in {
    animation: none;
  }

  .page-about .ab-room-card,
  .page-about .ab-node .disclosure-toggle {
    transition: none;
  }
}
<<<END>>>