.page-about {
  --ab-timeline-x: 20px;
  color: var(--paper);
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  padding: calc(var(--header-h) + clamp(20px, 4vw, 44px)) 0 clamp(26px, 4vw, 44px);
}

.page-about .ab-hero .breadcrumb {
  margin-bottom: clamp(18px, 3vw, 28px);
}

.page-about .ab-hero h1 {
  margin: 14px 0 0;
  font-size: clamp(1.9rem, 4.6vw, 3.2rem);
  line-height: 1.16;
  letter-spacing: -0.02em;
  font-weight: 800;
  max-width: 18em;
}

.page-about .ab-hero .lede {
  margin: clamp(16px, 2.4vw, 24px) 0 0;
  max-width: 46em;
  color: var(--muted);
  font-size: clamp(1rem, 1.6vw, 1.075rem);
  line-height: 1.85;
}

/* 首屏数字条 */
.page-about .ab-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin-top: clamp(26px, 4vw, 44px);
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.page-about .ab-fact {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: clamp(16px, 2.4vw, 26px);
  background: var(--ink-soft);
}

.page-about .ab-fact-num {
  font-family: var(--font-mono);
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}

.page-about .ab-fact-num i {
  font-style: normal;
  margin-left: 4px;
  font-size: 0.4em;
  font-weight: 500;
  color: var(--muted);
}

.page-about .ab-fact-label {
  font-size: 0.85rem;
  line-height: 1.65;
  color: var(--muted);
}

/* ---------- 章节骨架 ---------- */
.page-about .ab-shell {
  padding-bottom: clamp(40px, 6vw, 84px);
}

.page-about .ab-index {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding-bottom: 14px;
  scrollbar-width: none;
  -webkit-overflow-scrolling: touch;
}

.page-about .ab-index::-webkit-scrollbar {
  display: none;
}

.page-about .ab-index-link {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 14px;
  border-radius: var(--radius-pill);
  border: 1px solid var(--line);
  background: var(--ink-soft);
  color: var(--muted);
  text-decoration: none;
  font-size: 0.82rem;
  white-space: nowrap;
  transition: color 0.24s var(--ease), border-color 0.24s var(--ease);
}

.page-about .ab-index-link em {
  font-style: normal;
}

.page-about .ab-index-link .mono {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--cyan);
}

.page-about .ab-index-link:hover,
.page-about .ab-index-link[aria-current="true"],
.page-about .ab-index-link[aria-current="page"] {
  color: var(--paper);
  border-color: var(--cyan);
}

.page-about .ab-chapter {
  padding: clamp(36px, 5.5vw, 72px) 0;
  border-top: 1px solid var(--line);
}

.page-about .ab-chapter:first-child {
  border-top: 0;
  padding-top: clamp(8px, 2vw, 20px);
}

.page-about .ab-head {
  max-width: 60em;
}

.page-about .ab-chapter-no {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-size: 0.82rem;
  letter-spacing: 0.22em;
  color: var(--cyan);
}

.page-about .ab-chapter-no::after {
  content: "";
  width: clamp(28px, 6vw, 72px);
  height: 1px;
  background: var(--line);
}

.page-about .ab-head h2 {
  margin: 14px 0 0;
  font-size: clamp(1.5rem, 3.2vw, 2.4rem);
  line-height: 1.2;
  letter-spacing: -0.02em;
  font-weight: 800;
}

.page-about .ab-conclusion {
  margin: clamp(14px, 2vw, 20px) 0 0;
  padding-left: 16px;
  border-left: 2px solid var(--cyan);
  max-width: 44em;
  font-size: clamp(0.98rem, 1.5vw, 1.075rem);
  line-height: 1.8;
  color: var(--paper);
}

.page-about .ab-body-text {
  margin: 0;
  max-width: 42em;
  font-size: 1rem;
  line-height: 1.85;
  color: var(--muted);
}

/* 通用非对称行 */
.page-about .ab-split-row {
  margin-top: clamp(24px, 3.4vw, 40px);
  gap: clamp(20px, 3vw, 40px);
}

.page-about .ab-split-row > * {
  min-width: 0;
}

/* ---------- 01 时间轴 ---------- */
.page-about .ab-timeline {
  position: relative;
  margin-top: clamp(26px, 4vw, 44px);
  max-width: 62em;
}

.page-about .ab-timeline::before {
  content: "";
  position: absolute;
  left: var(--ab-timeline-x);
  top: 10px;
  bottom: 10px;
  width: 2px;
  border-radius: 2px;
  background: linear-gradient(180deg, var(--cyan) 0%, var(--line) 26%, var(--line) 100%);
  opacity: 0.65;
}

.page-about .ab-node {
  position: relative;
  padding-left: 60px;
  padding-bottom: clamp(14px, 2.2vw, 24px);
}

.page-about .ab-node:last-of-type {
  padding-bottom: 0;
}

.page-about .ab-node-mark {
  position: absolute;
  left: 0;
  top: 6px;
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  border-radius: var(--radius-pill);
  background: var(--ink);
  border: 1px solid var(--line);
}

.page-about .ab-node-ver {
  font-size: 0.88rem;
  font-weight: 700;
  color: var(--cyan-soft);
  font-variant-numeric: tabular-nums;
}

.page-about .ab-node--now .ab-node-mark {
  border-color: var(--orange);
  box-shadow: 0 0 0 4px rgba(255, 122, 41, 0.14);
}

.page-about .ab-node--now .ab-node-ver {
  color: var(--orange);
}

.page-about .ab-node-card {
  background: var(--ink-soft);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  padding: clamp(15px, 2.2vw, 22px);
  transition: transform 0.32s var(--ease), border-color 0.32s var(--ease);
}

.page-about .ab-node-card:hover {
  transform: translateY(-4px);
  border-color: var(--cyan);
}

.page-about .ab-node-card h3 {
  margin: 0 0 8px;
  font-size: clamp(1rem, 1.8vw, 1.2rem);
  line-height: 1.4;
  font-weight: 700;
}

.page-about .ab-node-card p {
  margin: 0;
  font-size: 0.94rem;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .ab-timeline-media {
  margin: clamp(18px, 3vw, 30px) 0 clamp(20px, 3vw, 32px) 60px;
}

/* ---------- 媒体位 ---------- */
.page-about .media-frame {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius-lg);
  border: 1px solid var(--line);
  background: var(--ink-soft);
}

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

.page-about .ab-media {
  margin: clamp(24px, 4vw, 40px) 0 0;
}

.page-about .ab-media-square {
  margin: 0;
}

/* ---------- 02 数据流程 ---------- */
.page-about .ab-flow {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  list-style: none;
  margin: clamp(26px, 4vw, 40px) 0 0;
  padding: 0;
}

.page-about .ab-flow-step {
  position: relative;
  padding: clamp(18px, 2.6vw, 26px);
  border-radius: var(--radius-lg);
  border: 1px solid var(--line);
  background: var(--ink-soft);
}

.page-about .ab-flow-step::after {
  content: "";
  position: absolute;
  left: clamp(18px, 2.6vw, 26px);
  right: clamp(18px, 2.6vw, 26px);
  top: 0;
  height: 2px;
  border-radius: 2px;
  background: var(--line);
}

.page-about .ab-flow-step[data-stage="capture"]::after {
  background: var(--cyan);
}

.page-about .ab-flow-step[data-stage="check"]::after {
  background: var(--sand);
}

.page-about .ab-flow-step[data-stage="review"]::after {
  background: var(--mint);
}

.page-about .ab-flow-badge {
  display: inline-block;
  padding: 4px 12px;
  border-radius: var(--radius-pill);
  border: 1px solid var(--line);
  font-size: 0.76rem;
  letter-spacing: 0.14em;
  color: var(--muted);
}

.page-about .ab-flow-step[data-stage="capture"] .ab-flow-badge {
  color: var(--cyan);
  border-color: var(--cyan);
}

.page-about .ab-flow-step[data-stage="check"] .ab-flow-badge {
  color: var(--sand);
  border-color: var(--sand);
}

.page-about .ab-flow-step[data-stage="review"] .ab-flow-badge {
  color: var(--mint);
  border-color: var(--mint);
}

.page-about .ab-flow-body h3 {
  margin: 14px 0 8px;
  font-size: clamp(1rem, 1.8vw, 1.18rem);
  font-weight: 700;
}

.page-about .ab-flow-body p {
  margin: 0;
  font-size: 0.93rem;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .ab-mini-panel {
  display: grid;
  gap: 4px;
  padding: clamp(18px, 2.6vw, 26px);
  border-radius: var(--radius-lg);
  border: 1px solid var(--line);
  background: var(--panel);
}

.page-about .ab-mini-num {
  font-family: var(--font-mono);
  font-size: clamp(1.6rem, 3.4vw, 2.2rem);
  font-weight: 700;
  line-height: 1.1;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}

.page-about .ab-mini-num i {
  font-style: normal;
  margin-left: 3px;
  font-size: 0.4em;
  color: var(--muted);
}

.page-about .ab-mini-label {
  font-size: 0.82rem;
  line-height: 1.6;
  color: var(--muted);
  margin-bottom: 14px;
}

.page-about .ab-mini-label:last-child {
  margin-bottom: 0;
}

/* ---------- 03 团队 ---------- */
.page-about .ab-team-bar {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin-top: clamp(24px, 3.6vw, 40px);
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.page-about .ab-team-stat {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: clamp(16px, 2.4vw, 26px);
  background: var(--ink-soft);
}

.page-about .ab-team-num {
  font-size: clamp(1.7rem, 3.8vw, 2.5rem);
  font-weight: 700;
  line-height: 1;
  color: var(--paper);
  font-variant-numeric: tabular-nums;
}

.page-about .ab-team-num i {
  font-style: normal;
  margin-left: 4px;
  font-size: 0.42em;
  color: var(--muted);
}

.page-about .ab-team-tag {
  font-size: 0.84rem;
  color: var(--muted);
}

.page-about .ab-side-panel {
  padding: clamp(18px, 2.6vw, 26px);
  border-radius: var(--radius-lg);
  background: var(--panel);
  border: 1px solid var(--line);
}

.page-about .ab-side-panel h3 {
  margin: 0 0 10px;
  font-size: 1rem;
  font-weight: 700;
}

.page-about .ab-side-panel p {
  margin: 0 0 16px;
  font-size: 0.9rem;
  line-height: 1.8;
  color: var(--muted);
}

/* ---------- 04 覆盖与场景 ---------- */
.page-about .ab-leagues {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  list-style: none;
  margin: clamp(24px, 3.6vw, 40px) 0 0;
  padding: 0;
}

.page-about .ab-leagues li {
  padding: clamp(16px, 2.4vw, 24px);
  border-radius: var(--radius-md);
  border: 1px solid var(--line);
  background: var(--ink-soft);
}

.page-about .ab-league-name {
  display: inline-block;
  padding: 4px 12px;
  border-radius: var(--radius-pill);
  background: rgba(34, 230, 211, 0.1);
  color: var(--cyan);
  font-size: 0.78rem;
  letter-spacing: 0.08em;
}

.page-about .ab-leagues p {
  margin: 12px 0 0;
  font-size: 0.93rem;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .ab-scenes {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  margin-top: clamp(20px, 3vw, 30px);
}

.page-about .ab-scene {
  padding: clamp(18px, 2.6vw, 26px);
  border-radius: var(--radius-lg);
  background: linear-gradient(160deg, var(--panel) 0%, var(--ink-soft) 100%);
  border: 1px solid var(--line);
  transition: transform 0.32s var(--ease), border-color 0.32s var(--ease);
}

.page-about .ab-scene:hover {
  transform: translateY(-4px);
  border-color: var(--cyan);
}

.page-about .ab-scene-tag {
  display: inline-block;
  padding: 3px 10px;
  border-radius: var(--radius-pill);
  border: 1px solid var(--orange);
  color: var(--orange);
  font-size: 0.74rem;
  letter-spacing: 0.12em;
}

.page-about .ab-scene h3 {
  margin: 14px 0 8px;
  font-size: clamp(1rem, 1.8vw, 1.15rem);
  font-weight: 700;
}

.page-about .ab-scene p {
  margin: 0;
  font-size: 0.92rem;
  line-height: 1.8;
  color: var(--muted);
}

/* ---------- 05 合作与资质 ---------- */
.page-about .ab-certs {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin-top: clamp(24px, 3.6vw, 40px);
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius-xl);
  overflow: hidden;
}

.page-about .ab-cert {
  padding: clamp(18px, 2.8vw, 30px);
  background: var(--ink-soft);
  transition: background 0.32s var(--ease);
}

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

.page-about .ab-cert-num {
  display: block;
  font-size: clamp(2rem, 4.4vw, 3rem);
  font-weight: 700;
  line-height: 1;
  color: var(--orange);
  font-variant-numeric: tabular-nums;
}

.page-about .ab-cert h3 {
  margin: 14px 0 8px;
  font-size: clamp(1rem, 1.8vw, 1.12rem);
  font-weight: 700;
}

.page-about .ab-cert p {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.78;
  color: var(--muted);
}

/* ---------- 06 折叠与结尾 ---------- */
.page-about .ab-fold {
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--ink-soft);
  margin-bottom: 12px;
  overflow: hidden;
}

.page-about .ab-fold .fold-head {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: clamp(15px, 2.2vw, 20px) clamp(16px, 2.4vw, 24px);
  background: none;
  border: 0;
  color: var(--paper);
  font-family: var(--font-body);
  font-size: clamp(0.98rem, 1.7vw, 1.08rem);
  font-weight: 700;
  text-align: left;
  cursor: pointer;
  transition: color 0.24s var(--ease);
}

.page-about .ab-fold .fold-head:hover {
  color: var(--cyan);
}

.page-about .ab-fold .fold-head::after {
  content: "+";
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: 1.15rem;
  color: var(--cyan);
  line-height: 1;
}

.page-about .ab-fold[data-open] .fold-head::after {
  content: "−";
}

.page-about .ab-fold .fold-body {
  padding: 0 clamp(16px, 2.4vw, 24px) clamp(16px, 2.4vw, 22px);
}

.page-about .ab-fold .fold-body p {
  margin: 0;
  font-size: 0.93rem;
  line-height: 1.85;
  color: var(--muted);
}

.page-about .ab-cta {
  margin-top: clamp(20px, 3vw, 36px);
  padding: clamp(26px, 4vw, 44px);
  border-radius: var(--radius-xl);
  border: 1px solid var(--line);
  background: linear-gradient(135deg, var(--panel) 0%, var(--ink-soft) 58%, var(--ink) 100%);
}

.page-about .ab-cta h2 {
  margin: 0;
  font-size: clamp(1.3rem, 2.6vw, 1.9rem);
  line-height: 1.25;
  font-weight: 800;
}

.page-about .ab-cta p {
  margin: 14px 0 0;
  max-width: 42em;
  font-size: 0.97rem;
  line-height: 1.85;
  color: var(--muted);
}

.page-about .ab-cta .btn-row {
  margin-top: clamp(18px, 2.6vw, 28px);
}

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

  .page-about .ab-flow {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px;
  }
}

@media (min-width: 820px) {
  .page-about .ab-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

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

@media (min-width: 900px) {
  .page-about .ab-scenes {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 1080px) {
  .page-about .ab-shell {
    display: grid;
    grid-template-columns: 104px minmax(0, 1fr);
    gap: clamp(24px, 4vw, 56px);
    align-items: start;
  }

  .page-about .ab-index {
    position: sticky;
    top: calc(var(--header-h) + 24px);
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .ab-index-link {
    flex-direction: column;
    align-items: flex-start;
    gap: 2px;
    padding: 10px 12px;
    border-radius: 0 var(--radius-md) var(--radius-md) 0;
    border: 0;
    border-left: 1px solid var(--line);
    background: transparent;
  }

  .page-about .ab-index-link em {
    font-size: 0.74rem;
  }

  .page-about .ab-index-link:hover,
  .page-about .ab-index-link[aria-current="true"],
  .page-about .ab-index-link[aria-current="page"] {
    border-left-color: var(--cyan);
    background: rgba(34, 230, 211, 0.06);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-node-card,
  .page-about .ab-scene,
  .page-about .ab-cert,
  .page-about .ab-index-link {
    transition: none;
  }

  .page-about .ab-node-card:hover,
  .page-about .ab-scene:hover {
    transform: none;
  }
}