.page-about {
  --ab-about-pad: clamp(40px, 6vw, 76px);
  color: var(--ab-body);
}

.page-about img {
  max-width: 100%;
}

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

.page-about .media-frame {
  margin: 0;
  overflow: hidden;
  border: 1px solid var(--ab-line);
  border-radius: var(--ab-radius);
  background: var(--ab-raise);
}

.page-about .media-frame__caption {
  font-size: 13px;
  line-height: 1.6;
  color: var(--ab-muted);
  padding: 10px 14px;
  background: var(--ab-deep);
}

/* ---------- 首屏叙事分屏 ---------- */
.page-about .ab-lead-block {
  display: grid;
  gap: clamp(26px, 4vw, 48px);
  padding: clamp(16px, 3vw, 34px) 0 clamp(30px, 4.5vw, 56px);
}

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

.page-about .ab-lead-block h1 {
  margin: 14px 0 0;
  max-width: 18ch;
  color: var(--ab-ink);
  font-family: var(--ab-font-display);
  font-weight: 900;
  letter-spacing: -0.02em;
  line-height: 1.02;
}

.page-about .ab-lead {
  margin-top: 20px;
  max-width: 62ch;
  color: var(--ab-body);
}

.page-about .ab-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin-top: 30px;
  background: var(--ab-line);
  border: 1px solid var(--ab-line);
  border-radius: var(--ab-radius);
  overflow: hidden;
}

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

.page-about .ab-fact__num {
  display: block;
  font-family: var(--ab-font-mono);
  font-size: clamp(22px, 3vw, 28px);
  line-height: 1.1;
  color: var(--ab-cyan);
}

.page-about .ab-fact__label {
  display: block;
  margin-top: 6px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--ab-muted);
}

/* 运营速览浮层 */
.page-about .ab-snap {
  align-self: start;
  padding: 22px 22px 10px;
  border-top: 2px solid var(--ab-cyan);
}

.page-about .ab-snap__head {
  margin: 0 0 8px;
  color: var(--ab-cyan);
}

.page-about .ab-snap__row {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 16px;
  align-items: baseline;
  justify-content: space-between;
  padding: 13px 0;
  border-bottom: 1px dashed var(--ab-line);
}

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

.page-about .ab-snap__key {
  font-size: 13px;
  color: var(--ab-muted);
}

.page-about .ab-snap__val {
  font-family: var(--ab-font-mono);
  font-size: 16px;
  color: var(--ab-ink);
}

/* ---------- 章节索引 ---------- */
.page-about .chapter-index {
  padding-bottom: clamp(24px, 3.5vw, 40px);
}

.page-about .chapter-index__list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .chapter-index__link {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 12px 14px;
  border: 1px solid var(--ab-line);
  border-radius: var(--ab-radius);
  background: var(--ab-deep);
  color: var(--ab-body);
  font-size: 14px;
  text-decoration: none;
  transition: border-color var(--ab-t), color var(--ab-t), background var(--ab-t);
}

.page-about .chapter-index__link:hover,
.page-about .chapter-index__link:focus-visible {
  border-color: var(--ab-cyan);
  background: var(--ab-raise);
  color: var(--ab-ink);
}

.page-about .chapter-index__num {
  font-family: var(--ab-font-mono);
  font-size: 12px;
  color: var(--ab-cyan);
}

/* ---------- 通用区块 ---------- */
.page-about .ab-block {
  padding: var(--ab-about-pad) 0;
  border-top: 1px solid var(--ab-line);
}

.page-about .ab-block--last {
  padding-bottom: clamp(48px, 7vw, 96px);
}

.page-about .ab-head {
  display: grid;
  gap: 10px;
  margin-bottom: clamp(20px, 3vw, 34px);
  max-width: 68ch;
}

.page-about .ab-head .section-title {
  margin: 0;
  color: var(--ab-ink);
}

.page-about .ab-head__note {
  margin: 0;
  font-size: 15px;
  line-height: 1.7;
  color: var(--ab-muted);
}

.page-about .prose p {
  margin: 0 0 16px;
  font-size: 16px;
  line-height: 1.75;
}

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

/* ---------- 起点与时间线 ---------- */
.page-about .ab-start__prose {
  max-width: 68ch;
}

.page-about .ab-filter {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: clamp(22px, 3vw, 34px) 0 16px;
}

.page-about .filter-chip {
  font-family: var(--ab-font-body);
  font-size: 13px;
  padding: 8px 14px;
  border-radius: 999px;
  border: 1px solid var(--ab-line);
  background: var(--ab-deep);
  color: var(--ab-muted);
  cursor: pointer;
  transition: color var(--ab-t), border-color var(--ab-t), background var(--ab-t);
}

.page-about .filter-chip:hover,
.page-about .filter-chip:focus-visible {
  color: var(--ab-ink);
  border-color: var(--ab-cyan);
}

.page-about .filter-chip[aria-pressed="true"] {
  background: rgba(0, 229, 255, 0.12);
  border-color: var(--ab-cyan);
  color: var(--ab-cyan);
}

.page-about .ab-timeline {
  overflow-x: auto;
  padding-bottom: 10px;
  scrollbar-width: thin;
}

.page-about .ab-timeline__track {
  display: flex;
  gap: 12px;
  min-width: 100%;
}

.page-about .ab-node {
  flex: 0 0 80%;
  min-width: 0;
  scroll-snap-align: start;
  padding: 18px;
  background: var(--ab-raise);
  border: 1px solid var(--ab-line);
  border-top: 2px solid var(--ab-cyan);
  border-radius: var(--ab-radius);
}

.page-about .ab-node__year {
  display: inline-block;
  font-family: var(--ab-font-mono);
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--ab-cyan);
}

.page-about .ab-node__title {
  margin: 8px 0 8px;
  font-size: 20px;
  font-weight: 800;
  color: var(--ab-ink);
}

.page-about .ab-node__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.7;
  color: var(--ab-body);
}

/* ---------- 团队分工 ---------- */
.page-about .ab-team__layout {
  display: grid;
  gap: clamp(20px, 3vw, 36px);
}

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

.page-about .ab-team__card {
  padding: 20px;
  background: var(--ab-deep);
  border: 1px solid var(--ab-line);
  border-radius: var(--ab-radius);
  transition: border-color var(--ab-t), box-shadow var(--ab-t), transform var(--ab-t);
}

.page-about .ab-team__card:hover,
.page-about .ab-team__card:focus-within,
.page-about .ab-team__card:focus-visible {
  border-color: var(--ab-cyan);
  box-shadow: 0 14px 30px rgba(0, 229, 255, 0.1);
  outline: none;
}

.page-about .ab-team__name {
  margin: 0;
  font-size: 20px;
  font-weight: 800;
  color: var(--ab-ink);
}

.page-about .ab-team__role {
  margin: 6px 0 0;
  font-family: var(--ab-font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--ab-orange);
}

.page-about .ab-team__detail {
  margin: 12px 0 0;
  font-size: 15px;
  line-height: 1.7;
  color: var(--ab-body);
}

/* ---------- 规模数据 ---------- */
.page-about .ab-scale__layout {
  display: grid;
  gap: clamp(20px, 3vw, 36px);
}

.page-about .ab-scale__grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.page-about .ab-stat {
  padding: 18px;
  background: var(--ab-raise);
  border-radius: var(--ab-radius);
  border-left: 3px solid var(--ab-cyan);
}

.page-about .ab-stat--orange {
  border-left-color: var(--ab-orange);
}

.page-about .ab-stat__num {
  display: block;
  font-family: var(--ab-font-mono);
  font-size: clamp(26px, 4vw, 38px);
  line-height: 1;
  color: var(--ab-ink);
}

.page-about .ab-stat--orange .ab-stat__num {
  color: var(--ab-orange);
}

.page-about .ab-stat__label {
  display: block;
  margin-top: 8px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--ab-muted);
}

/* ---------- 更新窗口 ---------- */
.page-about .ab-windows {
  display: grid;
  gap: 14px;
}

.page-about .ab-window {
  padding: 22px 20px;
  background: var(--ab-deep);
  border: 1px solid var(--ab-line);
  border-radius: var(--ab-radius);
}

.page-about .ab-window__idx {
  font-family: var(--ab-font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--ab-orange);
}

.page-about .ab-window__title {
  margin: 10px 0 10px;
  font-size: 22px;
  font-weight: 800;
  color: var(--ab-ink);
}

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

.page-about .ab-window__media {
  margin-top: clamp(22px, 3vw, 34px);
}

/* ---------- 合作与推荐 ---------- */
.page-about .ab-partner__list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .ab-partner__item {
  display: flex;
  gap: 16px;
  align-items: flex-start;
  padding: 20px 0;
  border-bottom: 1px solid var(--ab-line);
}

.page-about .ab-partner__item:first-child {
  border-top: 1px solid var(--ab-line);
}

.page-about .ab-partner__mark {
  flex: 0 0 auto;
  min-width: 52px;
  font-family: var(--ab-font-mono);
  font-size: 14px;
  color: var(--ab-cyan);
  padding-top: 4px;
}

.page-about .ab-partner__item h3 {
  margin: 0 0 8px;
  color: var(--ab-ink);
}

.page-about .ab-partner__item p {
  margin: 0;
  font-size: 15px;
  line-height: 1.72;
  color: var(--ab-body);
  max-width: 68ch;
}

/* ---------- 邀请 ---------- */
.page-about .ab-cta {
  padding: clamp(24px, 4vw, 44px);
  border: 1px solid var(--ab-line);
  border-radius: var(--ab-radius);
  background:
    linear-gradient(135deg, rgba(0, 229, 255, 0.14), rgba(255, 122, 26, 0.1)),
    var(--ab-raise);
}

.page-about .ab-cta .section-title {
  margin: 10px 0 16px;
  color: var(--ab-ink);
}

.page-about .ab-cta__prose {
  max-width: 68ch;
}

.page-about .ab-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 24px;
}

/* ---------- 断点 ---------- */
@media (min-width: 700px) {
  .page-about .chapter-index__list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

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

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

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

@media (min-width: 980px) {
  .page-about .ab-lead-block {
    grid-template-columns: 7fr 5fr;
    align-items: start;
  }

  .page-about .ab-team__layout {
    grid-template-columns: 1.25fr 0.85fr;
    align-items: start;
  }

  .page-about .ab-scale__layout {
    grid-template-columns: 1.35fr 0.9fr;
    align-items: start;
  }

  .page-about .ab-team__detail {
    max-height: 0;
    margin-top: 0;
    overflow: hidden;
    opacity: 0;
    transition: max-height 0.28s ease, opacity 0.28s ease, margin-top 0.28s ease;
  }

  .page-about .ab-team__card:hover .ab-team__detail,
  .page-about .ab-team__card:focus-within .ab-team__detail,
  .page-about .ab-team__card:focus-visible .ab-team__detail {
    max-height: 220px;
    margin-top: 12px;
    opacity: 1;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-team__card,
  .page-about .ab-team__detail,
  .page-about .chapter-index__link,
  .page-about .filter-chip {
    transition: none;
  }

  .page-about .ab-team__card:hover {
    transform: none;
  }
}