.page-about {
  --ab-side: 168px;
  --ab-gap: clamp(1.5rem, 4vw, 3.25rem);
  --ab-pad: clamp(3rem, 7vw, 5.5rem);
  display: block;
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  position: relative;
  padding: clamp(1.5rem, 4vw, 2.75rem) 0 clamp(2.5rem, 6vw, 4.5rem);
  border-bottom: 1px solid var(--line-soft);
  background:
    radial-gradient(760px 360px at 84% -10%, rgba(34, 211, 238, 0.13), transparent 65%),
    radial-gradient(620px 320px at 6% 4%, rgba(255, 159, 28, 0.08), transparent 62%);
}

.page-about .breadcrumb {
  margin-bottom: clamp(1.5rem, 4vw, 2.5rem);
  font-size: 0.82rem;
  letter-spacing: 0.08em;
}

.page-about .ab-hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.75rem, 4vw, 3rem);
}

.page-about .ab-hero__title {
  margin: 0.75rem 0 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(1.95rem, 5.2vw, 3.45rem);
  line-height: 1.2;
  letter-spacing: 0.02em;
  color: var(--text);
}

.page-about .ab-hero__lede {
  margin: 1.25rem 0 0;
  max-width: 58ch;
  font-size: clamp(0.96rem, 1.6vw, 1.06rem);
  line-height: 1.85;
  color: var(--text-dim);
}

.page-about .ab-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  margin-top: 1.75rem;
}

.page-about .ab-hero__panel {
  padding: clamp(1.25rem, 3vw, 1.75rem);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(155deg, var(--ink-800) 0%, var(--ink-850) 100%);
  box-shadow: inset 0 1px 0 rgba(34, 211, 238, 0.16);
}

.page-about .ab-ladder {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  align-items: end;
  gap: 0.65rem;
  height: clamp(140px, 24vw, 190px);
}

.page-about .ab-ladder__step {
  display: block;
  height: 40%;
  border: 1px solid var(--ink-600);
  border-radius: var(--radius);
  background: linear-gradient(180deg, rgba(34, 211, 238, 0.22), rgba(18, 27, 74, 0.15));
  transition: height 0.5s var(--ease);
}

.page-about .ab-ladder__step:nth-child(2) {
  height: 68%;
  background: linear-gradient(180deg, rgba(34, 211, 238, 0.44), rgba(30, 42, 107, 0.2));
}

.page-about .ab-ladder__step:nth-child(3) {
  height: 96%;
  border-color: var(--amber);
  background: linear-gradient(180deg, rgba(255, 159, 28, 0.6), rgba(217, 119, 6, 0.12));
  box-shadow: 0 0 26px rgba(255, 159, 28, 0.2);
}

.page-about .ab-hero__panel-cap {
  margin: 1rem 0 0;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--text-mute);
}

.page-about .ab-stats {
  margin: clamp(2rem, 5vw, 3.25rem) 0 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  padding: 0;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .ab-stats__item {
  background: var(--ink-900);
  padding: 1.1rem 1.1rem 1.25rem;
}

.page-about .ab-stats dt {
  font-family: var(--font-mono);
  font-size: 0.66rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-mute);
}

.page-about .ab-stats dd {
  margin: 0.5rem 0 0;
  font-family: var(--font-mono);
  font-size: clamp(1.05rem, 2.6vw, 1.5rem);
  font-weight: 600;
  letter-spacing: 0.03em;
  color: var(--amber);
}

/* ---------- 阶段通用骨架 ---------- */
.page-about .ab-phase {
  padding: var(--ab-pad) 0;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .ab-phase__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.25rem, 3.5vw, 2.5rem);
}

.page-about .ab-phase__side {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.page-about .ab-phase__num {
  font-family: var(--font-display);
  font-size: clamp(2.3rem, 5vw, 3.3rem);
  font-weight: 800;
  line-height: 0.85;
  letter-spacing: 0.04em;
  background: linear-gradient(180deg, var(--ink-600), rgba(51, 67, 154, 0.22));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.page-about .ab-phase__kicker {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--cyan);
}

.page-about .ab-phase__note {
  margin: 0.35rem 0 0;
  max-width: 24ch;
  padding-left: 0.75rem;
  border-left: 1px solid var(--line);
  font-size: 0.85rem;
  line-height: 1.75;
  color: var(--text-mute);
}

.page-about .ab-phase__body .section-title {
  margin: 0 0 1.1rem;
  max-width: 22ch;
}

.page-about .ab-phase__text {
  margin: 0 0 1.1rem;
  max-width: 64ch;
  font-size: 1rem;
  line-height: 1.85;
  color: var(--text-dim);
}

.page-about .ab-phase__text--tight {
  margin-top: 1.6rem;
  padding-left: 0.9rem;
  border-left: 2px solid var(--ink-600);
  font-size: 0.92rem;
  color: var(--text-mute);
}

.page-about .ab-phase__media {
  margin: 2rem 0 0;
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--ink-850);
}

.page-about .ab-phase__media img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.page-about .ab-phase__media .media__caption {
  padding: 0.75rem 1rem;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  color: var(--text-mute);
  border-top: 1px solid var(--line-soft);
}

/* ---------- 三级认证卡 ---------- */
.page-about .ab-cert {
  list-style: none;
  margin: 1.75rem 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .ab-cert__item {
  position: relative;
  background: var(--ink-900);
  padding: 1.15rem 1.15rem 1.35rem;
}

.page-about .ab-cert__title {
  margin: 0 0 0.5rem;
  font-family: var(--font-head);
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  color: var(--text);
}

.page-about .ab-cert__title::before {
  content: "";
  display: block;
  width: 28px;
  height: 2px;
  margin-bottom: 0.65rem;
  background: var(--cyan);
}

.page-about .ab-cert__item:nth-child(2) .ab-cert__title::before {
  background: var(--ink-600);
}

.page-about .ab-cert__item:nth-child(3) .ab-cert__title::before {
  background: var(--amber);
}

.page-about .ab-cert__desc {
  margin: 0;
  font-size: 0.87rem;
  line-height: 1.75;
  color: var(--text-mute);
}

/* ---------- 时间轴 ---------- */
.page-about .ab-timeline {
  list-style: none;
  position: relative;
  margin: 2rem 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
}

.page-about .ab-timeline::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: linear-gradient(180deg, var(--cyan), var(--ink-600) 45%, rgba(255, 159, 28, 0.75));
}

.page-about .ab-timeline__node {
  position: relative;
  padding: 0 0 1.85rem 2rem;
  outline: none;
}

.page-about .ab-timeline__node:last-child {
  padding-bottom: 0;
}

.page-about .ab-timeline__node::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.35rem;
  width: 15px;
  height: 15px;
  border: 1px solid var(--ink-600);
  border-radius: 1px;
  background: var(--ink-900);
  transform: rotate(45deg);
  transition: border-color 0.3s var(--ease), background 0.3s var(--ease), box-shadow 0.3s var(--ease);
}

.page-about .ab-timeline__node:hover::before,
.page-about .ab-timeline__node:focus-within::before {
  border-color: var(--amber);
  background: var(--amber);
  box-shadow: 0 0 16px rgba(255, 159, 28, 0.55);
}

.page-about .ab-timeline__tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.66rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--cyan);
}

.page-about .ab-timeline__title {
  margin: 0.45rem 0 0.4rem;
  font-family: var(--font-head);
  font-size: 1rem;
  font-weight: 700;
  line-height: 1.4;
  letter-spacing: 0.03em;
  color: var(--text);
}

.page-about .ab-timeline__sum {
  margin: 0;
  font-size: 0.86rem;
  line-height: 1.72;
  color: var(--text-dim);
}

.page-about .ab-timeline__extra {
  margin: 0;
  max-height: 0;
  opacity: 0;
  overflow: hidden;
  padding-left: 0.65rem;
  border-left: 1px solid var(--amber);
  font-family: var(--font-mono);
  font-size: 0.73rem;
  line-height: 1.7;
  color: var(--amber);
  transition: max-height 0.4s var(--ease), opacity 0.3s var(--ease), margin-top 0.4s var(--ease);
}

.page-about .ab-timeline__node:hover .ab-timeline__extra,
.page-about .ab-timeline__node:focus-within .ab-timeline__extra {
  max-height: 8rem;
  opacity: 1;
  margin-top: 0.7rem;
}

/* ---------- 会员中心指标 ---------- */
.page-about .ab-facts {
  list-style: none;
  margin: 1.75rem 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .ab-facts__item {
  background: var(--ink-900);
  padding: 1.25rem 1.2rem 1.4rem;
  border-left: 2px solid transparent;
  transition: border-color 0.3s var(--ease), background 0.3s var(--ease);
}

.page-about .ab-facts__item:hover {
  border-left-color: var(--cyan);
  background: var(--ink-800);
}

.page-about .ab-facts__num {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: clamp(1.05rem, 2.4vw, 1.3rem);
  font-weight: 600;
  letter-spacing: 0.05em;
  color: var(--amber);
}

.page-about .ab-facts__title {
  margin: 0.55rem 0 0.45rem;
  font-family: var(--font-head);
  font-size: 0.98rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--text);
}

.page-about .ab-facts__desc {
  margin: 0;
  font-size: 0.87rem;
  line-height: 1.72;
  color: var(--text-mute);
}

/* ---------- 陕西城市标签 ---------- */
.page-about .ab-cities {
  list-style: none;
  margin: 1.75rem 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.page-about .ab-cities__item {
  padding: 0.42rem 0.85rem;
  border: 1px solid var(--ink-600);
  border-radius: var(--radius);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  color: var(--text-dim);
  background: rgba(30, 42, 107, 0.28);
  transition: border-color 0.3s var(--ease), color 0.3s var(--ease);
}

.page-about .ab-cities__item:hover {
  border-color: var(--cyan);
  color: var(--cyan-l);
}

.page-about .ab-cities__item.is-lead {
  border-color: var(--amber);
  color: var(--amber);
  background: rgba(255, 159, 28, 0.1);
}

.page-about .ab-cities__item.is-lead:hover {
  border-color: var(--amber-d);
  color: var(--mist);
}

.page-about .ab-phase__media--map img {
  max-height: 62vh;
}

/* ---------- 版本与资质 ---------- */
.page-about .ab-honor {
  margin: 1.9rem 0 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1.25rem;
}

.page-about .ab-honor__col {
  padding: 1.3rem 1.2rem 1.45rem;
  border: 1px solid var(--line-soft);
  border-top-width: 2px;
  border-radius: var(--radius);
  background: linear-gradient(170deg, rgba(30, 42, 107, 0.4), rgba(10, 17, 48, 0.9));
}

.page-about .ab-honor__col--cyan {
  border-top-color: var(--cyan);
}

.page-about .ab-honor__col--amber {
  border-top-color: var(--amber);
}

.page-about .ab-honor__title {
  margin: 0 0 0.9rem;
  font-family: var(--font-head);
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--text);
}

.page-about .ab-honor__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.6rem;
}

.page-about .ab-honor__list li {
  position: relative;
  padding-left: 1rem;
  font-size: 0.89rem;
  line-height: 1.72;
  color: var(--text-dim);
}

.page-about .ab-honor__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.68em;
  width: 6px;
  height: 1px;
  background: var(--ink-600);
}

.page-about .ab-honor__list .num {
  font-family: var(--font-mono);
  font-weight: 600;
  letter-spacing: 0.05em;
  color: var(--cyan-l);
}

.page-about .ab-honor__col--amber .ab-honor__list .num {
  color: var(--amber);
}

/* ---------- 收尾入口 ---------- */
.page-about .ab-cta {
  padding: clamp(2.75rem, 6vw, 4.5rem) 0 clamp(3rem, 7vw, 5rem);
}

.page-about .ab-cta__box {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.25rem, 3vw, 2.5rem);
  padding: clamp(1.5rem, 4vw, 2.5rem);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background:
    linear-gradient(120deg, rgba(34, 211, 238, 0.1), transparent 45%),
    linear-gradient(300deg, rgba(255, 159, 28, 0.12), transparent 50%),
    var(--ink-800);
}

.page-about .ab-cta__title {
  margin: 0.6rem 0 0;
  max-width: 24ch;
  font-family: var(--font-display);
  font-size: clamp(1.35rem, 3vw, 2rem);
  font-weight: 800;
  line-height: 1.35;
  letter-spacing: 0.02em;
  color: var(--text);
}

.page-about .ab-cta__text {
  margin: 0.9rem 0 0;
  max-width: 52ch;
  font-size: 0.94rem;
  line-height: 1.8;
  color: var(--text-dim);
}

.page-about .ab-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  align-content: start;
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .ab-cert {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

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

@media (min-width: 900px) {
  .page-about .ab-hero__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: end;
    gap: clamp(2rem, 5vw, 4rem);
  }

  .page-about .ab-phase__grid {
    grid-template-columns: var(--ab-side) minmax(0, 1fr);
    gap: clamp(1.75rem, 5vw, 4rem);
  }

  .page-about .ab-phase__side {
    position: sticky;
    top: calc(var(--header-h) + 1.75rem);
    align-self: start;
  }

  .page-about .ab-cert__item {
    padding: 1.5rem 1.35rem 1.7rem;
  }

  .page-about .ab-timeline {
    grid-template-columns: repeat(5, minmax(0, 1fr));
    gap: 1.1rem;
  }

  .page-about .ab-timeline::before {
    left: 0;
    right: 0;
    top: 7px;
    bottom: auto;
    width: auto;
    height: 1px;
    background: linear-gradient(90deg, var(--cyan), var(--ink-600) 45%, rgba(255, 159, 28, 0.78));
  }

  .page-about .ab-timeline__node {
    padding: 2rem 0 0;
  }

  .page-about .ab-timeline__node::before {
    top: 0;
    left: 0;
  }

  .page-about .ab-honor {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 1.5rem;
  }

  .page-about .ab-cta__box {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr);
    align-items: center;
  }

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

@media (min-width: 1200px) {
  .page-about .ab-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-ladder__step,
  .page-about .ab-timeline__node::before,
  .page-about .ab-timeline__extra,
  .page-about .ab-facts__item,
  .page-about .ab-cities__item {
    transition: none;
  }
}