.page-about {
  --ab-line: 1px solid var(--frost);
  color: var(--ink);
  font-family: var(--sans);
  line-height: 1.85;
  background: var(--paper);
}

.page-about .breadcrumb {
  padding: 18px 0 0;
}

/* ---------- 首屏 ---------- */

.page-about .ab-hero {
  padding: 26px 0 46px;
  background:
    radial-gradient(110% 130% at 92% -14%, rgba(124, 78, 158, 0.14), transparent 62%),
    linear-gradient(180deg, rgba(230, 223, 238, 0.5), transparent 78%),
    var(--paper);
  border-bottom: var(--ab-line);
}

.page-about .ab-hero-grid {
  display: grid;
  gap: 30px;
}

.page-about .ab-kicker {
  margin: 0 0 14px;
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--grape-mid);
}

.page-about .ab-hero-main h1 {
  margin: 0 0 20px;
  font-family: var(--serif);
  font-weight: 700;
  font-size: clamp(30px, 6vw, 56px);
  line-height: 1.16;
  letter-spacing: -0.01em;
  color: var(--grape);
}

.page-about .ab-lede {
  margin: 0 0 14px;
  max-width: 40ch;
  font-size: 17px;
  line-height: 1.85;
  color: var(--ink);
}

.page-about .ab-lede--sub {
  font-size: 16px;
  color: var(--grape-soft);
}

.page-about .ab-hero-stats {
  margin: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--frost);
  border: var(--ab-line);
  box-shadow: var(--shadow-1);
}

.page-about .ab-stat {
  background: var(--paper);
  padding: 14px 16px 16px;
}

.page-about .ab-stat dt {
  margin: 0;
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--grape-soft);
}

.page-about .ab-stat dd {
  margin: 6px 0 0;
  font-family: var(--mono);
  font-size: 26px;
  letter-spacing: 0.02em;
  color: var(--grape);
  line-height: 1.2;
}

/* ---------- 区块通用 ---------- */

.page-about .ab-section {
  padding: 52px 0;
  border-bottom: var(--ab-line);
}

.page-about .ab-section--mist {
  background: linear-gradient(180deg, rgba(230, 223, 238, 0.62), rgba(245, 242, 236, 0.9));
}

.page-about .ab-section--cta {
  border-bottom: 0;
  background: var(--vine);
  color: var(--paper);
}

.page-about .section-head {
  margin-bottom: 30px;
}

.page-about .section-head .idx {
  display: inline-block;
  margin-bottom: 10px;
}

.page-about .section-head h2 {
  margin: 0 0 10px;
  font-family: var(--serif);
  font-weight: 700;
  font-size: clamp(24px, 4.4vw, 34px);
  line-height: 1.28;
  letter-spacing: -0.01em;
  color: var(--grape);
}

.page-about .ab-section--cta .section-head h2,
.page-about .ab-section--cta h2 {
  color: var(--paper);
}

.page-about .section-head .sub {
  margin: 0;
  max-width: 46ch;
  font-size: 15px;
  color: var(--grape-soft);
}

/* ---------- 图片容器 ---------- */

.page-about .frame {
  overflow: hidden;
  border: var(--ab-line);
  background: var(--mist);
}

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

.page-about .ab-figure,
.page-about .ab-wide-figure {
  margin: 0;
}

.page-about .frame-caption {
  margin-top: 10px;
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--grape-soft);
}

.page-about .ab-wide-figure {
  margin-bottom: 30px;
}

/* ---------- 01 时间轴 ---------- */

.page-about .ab-tl-layout {
  display: grid;
  gap: 36px;
}

.page-about .ab-axis {
  position: relative;
  margin: 0;
  padding: 0 0 0 26px;
  list-style: none;
}

.page-about .ab-axis::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 10px;
  bottom: 10px;
  width: 1px;
  background: linear-gradient(180deg, var(--grape-mid), var(--frost) 42%, var(--frost));
}

.page-about .ab-node {
  position: relative;
  display: grid;
  grid-template-columns: 62px minmax(0, 1fr);
  column-gap: 16px;
  padding-bottom: 30px;
  cursor: default;
}

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

.page-about .ab-node::before {
  content: "";
  position: absolute;
  left: -26px;
  top: 9px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  border: 1px solid var(--grape-mid);
  background: var(--paper);
  transition: border-color 0.16s var(--ease), background 0.16s var(--ease), transform 0.16s var(--ease);
}

.page-about .ab-node:last-child::before {
  border-color: var(--amber);
  background: var(--amber);
}

.page-about .ab-node:hover::before,
.page-about .ab-node:focus-within::before {
  border-color: var(--amber);
  background: var(--amber);
  transform: scale(1.15);
}

.page-about .ab-node:focus-visible {
  outline: 2px solid var(--amber);
  outline-offset: 8px;
  border-radius: 2px;
}

.page-about .ab-year {
  padding-top: 2px;
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--grape);
}

.page-about .ab-node-body h3 {
  margin: 0 0 8px;
  font-family: var(--serif);
  font-weight: 700;
  font-size: 20px;
  line-height: 1.4;
  color: var(--ink);
  transition: color 0.16s var(--ease);
}

.page-about .ab-node:hover .ab-node-body h3,
.page-about .ab-node:focus-within .ab-node-body h3 {
  color: var(--grape-mid);
}

.page-about .ab-node-body p {
  margin: 0 0 8px;
  font-size: 16px;
  color: var(--ink);
}

.page-about .ab-node-extra {
  max-height: 0;
  margin: 0;
  overflow: hidden;
  opacity: 0;
  font-size: 15px !important;
  color: var(--grape-soft) !important;
  border-left: 2px solid var(--mist);
  padding-left: 0;
  transition: max-height 0.3s var(--ease), opacity 0.22s var(--ease), padding-left 0.3s var(--ease), margin-top 0.3s var(--ease);
}

.page-about .ab-node:hover .ab-node-extra,
.page-about .ab-node:focus-within .ab-node-extra {
  max-height: 160px;
  opacity: 1;
  margin-top: 10px;
  padding-left: 12px;
}

/* ---------- 02 团队 ---------- */

.page-about .ab-teams {
  position: relative;
  margin-top: 22px;
  padding-top: 34px;
  display: grid;
  gap: 30px;
}

.page-about .ab-teams::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--frost) 8%, var(--frost) 92%, transparent);
}

.page-about .ab-team {
  position: relative;
  padding: 20px 18px 22px;
  border: var(--ab-line);
  background: var(--paper);
  transition: border-color 0.16s var(--ease), background 0.16s var(--ease);
}

.page-about .ab-team::before {
  content: "";
  position: absolute;
  top: -34px;
  left: 24px;
  width: 1px;
  height: 34px;
  background: var(--frost);
  transition: background 0.16s var(--ease);
}

.page-about .ab-team:hover,
.page-about .ab-team:focus-within {
  border-color: var(--amber);
  background: linear-gradient(180deg, rgba(230, 223, 238, 0.55), var(--paper) 70%);
}

.page-about .ab-team:hover::before,
.page-about .ab-team:focus-within::before {
  background: var(--amber);
}

.page-about .ab-team:focus-visible {
  outline: 2px solid var(--amber);
  outline-offset: 4px;
}

.page-about .ab-team-count {
  margin: 0 0 10px;
  font-size: 26px;
  line-height: 1;
  letter-spacing: 0.06em;
  color: var(--grape-mid);
}

.page-about .ab-team h3 {
  margin: 0 0 8px;
  font-family: var(--serif);
  font-weight: 700;
  font-size: 20px;
  color: var(--ink);
}

.page-about .ab-team > p {
  margin: 0 0 12px;
  font-size: 16px;
}

.page-about .ab-team-list {
  margin: 0;
  padding: 12px 0 0;
  list-style: none;
  border-top: var(--ab-line);
}

.page-about .ab-team-list li {
  position: relative;
  padding-left: 18px;
  font-size: 15px;
  line-height: 1.75;
  color: var(--grape-soft);
}

.page-about .ab-team-list li + li {
  margin-top: 6px;
}

.page-about .ab-team-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 11px;
  width: 8px;
  height: 1px;
  background: var(--grape-mid);
}

/* ---------- 03 编号规则 ---------- */

.page-about .ab-rule-lead {
  display: grid;
  gap: 18px;
  padding: 22px 20px;
  border: var(--ab-line);
  border-left: 3px solid var(--grape);
  background: linear-gradient(180deg, rgba(230, 223, 238, 0.62), var(--paper));
}

.page-about .ab-rule-code {
  display: inline-block;
  align-self: start;
  font-size: 22px;
  letter-spacing: 0.1em;
  color: var(--grape);
  border: var(--ab-line);
  background: var(--paper);
  padding: 8px 14px;
  box-shadow: var(--shadow-1);
}

.page-about .ab-rule-lead-body h3 {
  margin: 0 0 8px;
  font-family: var(--serif);
  font-weight: 700;
  font-size: 20px;
  color: var(--ink);
}

.page-about .ab-rule-lead-body p {
  margin: 0;
  font-size: 16px;
}

.page-about .ab-rule-grid {
  display: grid;
  gap: 26px;
  margin-top: 26px;
}

.page-about .ab-rule-item {
  padding-top: 18px;
  border-top: 2px solid var(--frost);
}

.page-about .ab-rule-item h3 {
  margin: 0 0 8px;
  font-family: var(--serif);
  font-weight: 700;
  font-size: 20px;
  color: var(--grape);
}

.page-about .ab-rule-item p {
  margin: 0;
  font-size: 16px;
}

/* ---------- 04 更新节律 ---------- */

.page-about .ab-cadence-layout {
  display: grid;
  gap: 34px;
}

.page-about .ab-cadence-list {
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: var(--ab-line);
}

.page-about .ab-cadence-list li {
  display: grid;
  gap: 6px;
  padding: 18px 0;
  border-bottom: var(--ab-line);
}

.page-about .ab-cadence-list .tag {
  justify-self: start;
}

.page-about .ab-cadence-list strong {
  font-family: var(--serif);
  font-size: 20px;
  font-weight: 700;
  color: var(--grape);
  line-height: 1.4;
}

.page-about .ab-cadence-list p {
  margin: 0;
  font-size: 16px;
}

/* ---------- 05 服务地区与备案 ---------- */

.page-about .ab-region {
  display: grid;
  gap: 30px;
}

.page-about .ab-region-body p {
  margin: 0 0 14px;
  max-width: 46ch;
  font-size: 16px;
}

.page-about .ab-region-facts {
  margin: 0;
  display: grid;
  gap: 1px;
  background: var(--frost);
  border: var(--ab-line);
}

.page-about .ab-region-facts > div {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 16px;
  padding: 12px 16px;
  background: var(--paper);
}

.page-about .ab-region-facts dt {
  margin: 0;
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--grape-soft);
}

.page-about .ab-region-facts dd {
  margin: 0;
  font-size: 16px;
  color: var(--ink);
  text-align: right;
}

/* ---------- 06 长期维护 ---------- */

.page-about .ab-upkeep {
  display: grid;
  gap: 26px;
}

.page-about .ab-upkeep-item {
  padding: 22px 20px 24px;
  border: var(--ab-line);
  background: var(--paper);
  box-shadow: var(--shadow-1);
  transition: border-color 0.16s var(--ease);
}

.page-about .ab-upkeep-item:hover {
  border-color: var(--amber);
}

.page-about .ab-upkeep-num {
  margin: 0 0 10px;
  font-size: 26px;
  line-height: 1.15;
  letter-spacing: 0.04em;
  color: var(--grape);
}

.page-about .ab-upkeep-item h3 {
  margin: 0 0 8px;
  font-family: var(--serif);
  font-weight: 700;
  font-size: 20px;
  color: var(--ink);
}

.page-about .ab-upkeep-item p {
  margin: 0;
  font-size: 16px;
}

/* ---------- CTA ---------- */

.page-about .ab-cta-inner {
  padding: 34px 22px;
  border: 1px solid rgba(199, 196, 204, 0.32);
  background: linear-gradient(140deg, rgba(74, 42, 94, 0.55), rgba(23, 54, 46, 0.75));
  box-shadow: var(--shadow-1);
}

.page-about .ab-cta-inner h2 {
  margin: 0 0 10px;
  font-family: var(--serif);
  font-weight: 700;
  font-size: clamp(22px, 4vw, 30px);
  line-height: 1.3;
  color: var(--paper);
}

.page-about .ab-cta-inner p {
  margin: 0 0 20px;
  max-width: 44ch;
  font-size: 16px;
  color: rgba(245, 242, 236, 0.82);
}

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

/* ---------- 响应式 ---------- */

@media (min-width: 700px) {
  .page-about .ab-hero {
    padding: 36px 0 60px;
  }

  .page-about .ab-section {
    padding: 68px 0;
  }

  .page-about .ab-rule-lead {
    grid-template-columns: auto minmax(0, 1fr);
    align-items: start;
    gap: 26px;
    padding: 26px 24px;
  }

  .page-about .ab-rule-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 30px;
  }

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

  .page-about .ab-cta-inner {
    padding: 44px 40px;
  }
}

@media (min-width: 900px) {
  .page-about .ab-hero-grid {
    grid-template-columns: minmax(0, 1fr) 272px;
    gap: 52px;
    align-items: start;
  }

  .page-about .ab-teams {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 26px;
  }

  .page-about .ab-region {
    grid-template-columns: minmax(0, 1fr) minmax(0, 400px);
    gap: 54px;
    align-items: start;
  }

  .page-about .ab-upkeep {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 22px;
  }
}

@media (min-width: 1024px) {
  .page-about .ab-section {
    padding: 86px 0;
  }

  .page-about .ab-tl-layout {
    grid-template-columns: minmax(0, 1fr) 300px;
    gap: 60px;
    align-items: start;
  }

  .page-about .ab-cadence-layout {
    grid-template-columns: 292px minmax(0, 1fr);
    gap: 54px;
    align-items: start;
  }

  .page-about .ab-node {
    grid-template-columns: 76px minmax(0, 1fr);
    column-gap: 22px;
    padding-bottom: 38px;
  }

  .page-about .ab-wide-figure {
    margin-bottom: 40px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-node::before,
  .page-about .ab-node-extra,
  .page-about .ab-team,
  .page-about .ab-team::before,
  .page-about .ab-node-body h3,
  .page-about .ab-upkeep-item {
    transition: none;
  }
}