.page-about .ab-hero {
  position: relative;
  overflow: hidden;
  padding: var(--sp-6) 0 var(--sp-8);
  background:
    radial-gradient(120% 80% at 86% 0%, rgba(31, 224, 180, 0.12), transparent 62%),
    radial-gradient(90% 70% at 8% 100%, rgba(255, 166, 43, 0.09), transparent 66%);
}

.page-about .ab-hero .breadcrumb { margin-bottom: var(--sp-4); }

.page-about .ab-hero__grid {
  display: grid;
  gap: var(--sp-6);
}

.page-about .ab-hero__title {
  margin: var(--sp-1) 0 var(--sp-3);
  font-size: clamp(2.25rem, 8vw, 4rem);
  line-height: 1.05;
  letter-spacing: -0.015em;
}

.page-about .ab-hero__lead {
  max-width: 46ch;
  margin: 0 0 var(--sp-4);
  font-size: 1.0625rem;
  line-height: 1.8;
  color: var(--text-dim);
}

.page-about .ab-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-2);
}

.page-about .ab-hero__board {
  display: grid;
  gap: 1px;
  overflow: hidden;
  border: 1px solid var(--line-soft);
  border-radius: var(--r-lg);
  background: var(--line-soft);
}

.page-about .ab-stat {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: var(--sp-3);
  background: var(--ink-2);
}

.page-about .ab-stat__value {
  font-family: var(--font-mono);
  font-size: 1.75rem;
  font-weight: 700;
  line-height: 1;
  color: var(--amber);
  font-variant-numeric: tabular-nums;
}

.page-about .ab-stat__label {
  font-size: 0.875rem;
  color: var(--text-dim);
}

/* 发展历程 */
.page-about .ab-timeline { padding: var(--sp-8) 0; }

.page-about .ab-timeline__note {
  max-width: 54ch;
  margin: var(--sp-3) 0 0;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: rgba(11, 28, 44, 0.7);
}

.page-about .ab-timeline__track {
  position: relative;
  display: grid;
  gap: var(--sp-2);
  margin-top: var(--sp-6);
}

.page-about .ab-phase {
  position: relative;
  margin-top: 0;
  border: 1px solid rgba(11, 28, 44, 0.1);
  border-radius: var(--r-md);
  background: rgba(255, 255, 255, 0.78);
  transition: border-color var(--dur) var(--ease);
}

.page-about .ab-phase::before { display: none; }

.page-about .ab-phase[open] { border-color: rgba(194, 112, 79, 0.55); }

.page-about .ab-phase summary {
  position: relative;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 4px var(--sp-2);
  padding: var(--sp-3) var(--sp-3) var(--sp-4);
  cursor: pointer;
  list-style: none;
}

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

.page-about .ab-phase summary::after {
  content: "展开";
  position: absolute;
  right: var(--sp-3);
  bottom: 10px;
  font-size: 0.75rem;
  color: var(--clay);
}

.page-about .ab-phase[open] summary::after { content: "收起"; }

.page-about .ab-phase__num {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  color: var(--clay);
}

.page-about .ab-phase__ver {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--rock);
  text-align: right;
}

.page-about .ab-phase__name {
  grid-column: 1 / -1;
  font-size: 1.0625rem;
  font-weight: 700;
  line-height: 1.45;
  color: var(--ink);
}

.page-about .ab-phase__body {
  padding: 0 var(--sp-3) var(--sp-3);
}

.page-about .ab-phase__body p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.85;
  color: rgba(11, 28, 44, 0.76);
}

/* 四条内容线 */
.page-about .ab-lines { padding: var(--sp-8) 0; }

.page-about .ab-lines__grid {
  display: grid;
  gap: var(--sp-6);
  margin-top: var(--sp-6);
}

.page-about .ab-line {
  padding: var(--sp-3) 0;
  border-top: 1px solid var(--line-soft);
}

.page-about .ab-line__head {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
}

.page-about .ab-line__dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  flex: none;
}

.page-about .ab-line__dot--data { background: var(--neon); }
.page-about .ab-line__dot--dir { background: var(--clay); }
.page-about .ab-line__dot--log { background: var(--amber); }
.page-about .ab-line__dot--doc { background: var(--moss); }

.page-about .ab-line__title {
  margin: 0;
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--cream);
}

.page-about .ab-line__meta {
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-mute);
}

.page-about .ab-line__desc {
  margin: var(--sp-1) 0 var(--sp-2);
  font-size: 0.9375rem;
  line-height: 1.85;
  color: var(--text-dim);
}

.page-about .ab-line__link {
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--neon);
  text-decoration: none;
  border-bottom: 1px solid rgba(31, 224, 180, 0.4);
  padding-bottom: 2px;
}

.page-about .ab-line__link:hover { border-bottom-color: var(--neon); }

.page-about .ab-lines__figure {
  margin: 0;
  overflow: hidden;
  border-radius: var(--r-lg);
  border: 1px solid var(--line-soft);
}

/* 团队 */
.page-about .ab-team { padding: var(--sp-8) 0; }

.page-about .ab-team__grid {
  display: grid;
  gap: var(--sp-6);
  margin-top: var(--sp-6);
}

.page-about .ab-team__chart {
  display: grid;
  gap: var(--sp-4);
  justify-items: center;
  align-content: start;
}

.page-about .ab-ring {
  width: min(240px, 72vw);
  height: auto;
  overflow: visible;
}

.page-about .ab-ring__seg circle {
  transition: stroke-width var(--dur) var(--ease), opacity var(--dur) var(--ease);
}

.page-about .ab-ring__seg:hover circle { stroke-width: 22; }

.page-about .ab-ring__total {
  font-family: var(--font-mono);
  font-size: 24px;
  font-weight: 700;
  fill: var(--ink);
}

.page-about .ab-ring__unit {
  font-family: var(--font-body);
  font-size: 10px;
  fill: var(--rock);
}

.page-about .ab-legend {
  display: grid;
  gap: 10px;
  width: 100%;
  max-width: 320px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-legend__item {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.9375rem;
  color: var(--ink);
}

.page-about .ab-legend__swatch {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  flex: none;
}

.page-about .ab-legend__swatch--data { background: var(--neon); }
.page-about .ab-legend__swatch--eng { background: var(--amber); }
.page-about .ab-legend__swatch--comm { background: var(--moss); }
.page-about .ab-legend__swatch--ops { background: var(--clay); }

.page-about .ab-legend__num {
  margin-left: auto;
  font-family: var(--font-mono);
  color: var(--clay);
  font-variant-numeric: tabular-nums;
}

.page-about .ab-team__flow {
  margin-top: var(--sp-6);
  padding: var(--sp-4);
  border-radius: var(--r-lg);
  background: rgba(11, 28, 44, 0.05);
  border-left: 4px solid var(--neon-dark);
}

.page-about .ab-team__flow-title {
  margin: 0 0 var(--sp-2);
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--ink);
}

.page-about .ab-team__flow p {
  margin: 0;
  max-width: 68ch;
  font-size: 0.9375rem;
  line-height: 1.85;
  color: rgba(11, 28, 44, 0.78);
}

/* 合作生态 */
.page-about .ab-partners { padding: var(--sp-8) 0; }

.page-about .ab-partners__banner {
  margin: var(--sp-6) 0 0;
  overflow: hidden;
  border-radius: var(--r-lg);
  border: 1px solid var(--line-soft);
}

.page-about .ab-partners__grid {
  display: grid;
  gap: var(--sp-5, 32px);
  margin-top: var(--sp-6);
}

.page-about .ab-partners__intro p {
  max-width: 52ch;
  margin: 0 0 var(--sp-3);
  font-size: 1rem;
  line-height: 1.85;
  color: var(--text-dim);
}

.page-about .ab-partners__intro .btn { margin-top: var(--sp-1); }

.page-about .ab-chips {
  display: grid;
  gap: 12px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-chip {
  display: grid;
  gap: 4px;
  padding: 14px 20px;
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  background: var(--ink-2);
  transition: border-color var(--dur) var(--ease), background var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.page-about .ab-chip:hover,
.page-about .ab-chip:focus-within {
  border-color: var(--neon);
  background: var(--ink-3);
  transform: translateX(4px);
}

.page-about .ab-chip__title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--cream);
}

.page-about .ab-chip__desc {
  font-size: 0.875rem;
  line-height: 1.7;
  color: var(--text-mute);
  transition: color var(--dur) var(--ease);
}

.page-about .ab-chip:hover .ab-chip__desc { color: var(--text-dim); }

/* 理由 */
.page-about .ab-reasons { padding: var(--sp-8) 0; }

.page-about .ab-reasons__grid {
  display: grid;
  gap: var(--sp-4);
  margin-top: var(--sp-6);
}

.page-about .ab-reason {
  padding: var(--sp-4) 0 0;
  border-top: 2px solid rgba(11, 28, 44, 0.14);
}

.page-about .ab-reason__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  color: var(--clay);
}

.page-about .ab-reason__title {
  margin: var(--sp-2) 0 var(--sp-2);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--ink);
}

.page-about .ab-reason__desc {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.85;
  color: rgba(11, 28, 44, 0.76);
}

/* 收尾入口 */
.page-about .ab-next {
  padding: var(--sp-8) 0;
  background:
    radial-gradient(100% 120% at 0% 0%, rgba(31, 224, 180, 0.12), transparent 60%),
    var(--ink-2);
}

.page-about .ab-next__title {
  margin: 0 0 var(--sp-4);
  font-family: var(--font-heading);
  font-size: clamp(1.5rem, 4vw, 2rem);
  font-weight: 700;
  color: var(--cream);
}

.page-about .ab-next__links {
  display: grid;
  gap: var(--sp-2);
}

.page-about .ab-next__link {
  display: grid;
  gap: 6px;
  padding: var(--sp-3);
  border: 1px solid var(--line-soft);
  border-radius: var(--r-md);
  text-decoration: none;
  transition: border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .ab-next__link:hover {
  border-color: var(--neon);
  background: rgba(31, 224, 180, 0.07);
}

.page-about .ab-next__link-title {
  font-size: 1.0625rem;
  font-weight: 700;
  color: var(--neon);
}

.page-about .ab-next__link-desc {
  font-size: 0.875rem;
  line-height: 1.7;
  color: var(--text-dim);
}

/* 共享类在当前页的落位 */
.page-about .figure { margin: 0; }

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

.page-about .figure__caption {
  padding: 10px var(--sp-3) 0;
  font-size: 0.8125rem;
  line-height: 1.6;
  color: var(--text-mute);
}

.page-about .surface-light .figure__caption { color: rgba(11, 28, 44, 0.6); }

.page-about .surface-light {
  background: var(--cream);
  color: var(--ink);
}

.page-about .surface-light .section-title { border-left-color: var(--clay); }

.page-about .surface-light .eyebrow { color: var(--clay); }

.page-about .surface-light .figure {
  border: 1px solid rgba(11, 28, 44, 0.1);
  border-radius: var(--r-lg);
  overflow: hidden;
  background: rgba(255, 255, 255, 0.6);
}

.page-about .surface-light .figure__caption { padding: 10px var(--sp-3) var(--sp-2); }

@media (min-width: 640px) {
  .page-about .ab-hero__board { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .page-about .ab-chips { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .page-about .ab-next__links { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (min-width: 900px) {
  .page-about .ab-hero { padding: var(--sp-8) 0 var(--sp-12); }

  .page-about .ab-hero__grid {
    grid-template-columns: minmax(0, 6fr) minmax(0, 5fr);
    gap: var(--sp-8);
    align-items: end;
  }

  .page-about .ab-hero__board { grid-template-columns: 1fr; }

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

  .page-about .ab-timeline__track::before {
    content: "";
    position: absolute;
    top: 9px;
    left: 0;
    right: 0;
    height: 1px;
    background: var(--rock);
    opacity: 0.4;
  }

  .page-about .ab-phase {
    margin-top: 28px;
    background: rgba(255, 255, 255, 0.82);
  }

  .page-about .ab-phase::before {
    content: "";
    display: block;
    position: absolute;
    top: -24px;
    left: var(--sp-3);
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--clay);
    box-shadow: 0 0 0 4px var(--cream);
  }

  .page-about .ab-lines__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: var(--sp-8);
    align-items: start;
  }

  .page-about .ab-team__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: var(--sp-8);
    align-items: center;
  }

  .page-about .ab-team__flow {
    margin-top: var(--sp-8);
    padding: var(--sp-6);
  }

  .page-about .ab-partners__grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: var(--sp-8);
    align-items: start;
  }

  .page-about .ab-reasons__grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: var(--sp-6);
  }

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

.page-about {
  --sp-5: 1rem;
}