.page-about {
  --ab-muted: #D3CCBE;
  --ab-soft: #4A4740;
  --ab-tint: rgba(232, 69, 31, .12);
  background: var(--cream);
  color: var(--char);
  overflow-x: clip;
}

.page-about h1,
.page-about h2,
.page-about h3 {
  font-family: var(--font-head);
  letter-spacing: -.03em;
  line-height: 1.06;
  margin: 0;
}

.page-about p {
  margin: 0 0 14px;
  line-height: 1.72;
}

.page-about a {
  color: var(--data-deep);
}

/* ---------- 首屏 ---------- */

.page-about .ab-hero {
  position: relative;
  background: var(--char);
  color: var(--cream);
  padding: 20px 0 44px;
  overflow: hidden;
}

.page-about .ab-hero::before {
  content: "";
  position: absolute;
  top: -80px;
  right: -120px;
  width: 320px;
  height: 320px;
  background: var(--lava);
  opacity: .16;
  transform: rotate(24deg);
  pointer-events: none;
}

.page-about .ab-hero .crumbs-list,
.page-about .ab-hero .crumbs-list a {
  color: var(--ab-muted);
}

.page-about .ab-hero .crumbs-list a:hover {
  color: var(--lava);
}

.page-about .ab-hero-grid {
  display: grid;
  gap: 28px;
  position: relative;
  z-index: 1;
}

.page-about .ab-hero-tag {
  margin: 18px 0 14px;
}

.page-about .ab-hero h1 {
  font-size: clamp(34px, 8.4vw, 68px);
  font-weight: 900;
  color: var(--paper);
  max-width: 12em;
}

.page-about .ab-lede {
  margin: 18px 0 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--ab-muted);
  max-width: 40em;
}

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

.page-about .ab-hero-actions .btn {
  flex: 1 1 auto;
  text-align: center;
}

.page-about .ab-snapshot {
  position: relative;
  background: var(--graph);
  border-left: 3px solid var(--data);
  padding: 20px 20px 22px;
}

.page-about .ab-snapshot::after {
  content: "";
  position: absolute;
  right: -18px;
  bottom: -18px;
  width: 56px;
  height: 56px;
  background: var(--clay);
  transform: rotate(45deg);
  opacity: .22;
  pointer-events: none;
}

.page-about .ab-snapshot-label {
  margin: 0;
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--data);
}

.page-about .ab-snapshot-ver {
  margin: 4px 0 16px;
  font-size: clamp(30px, 8vw, 42px);
  font-weight: 700;
  line-height: 1;
  color: var(--paper);
  letter-spacing: -.02em;
}

.page-about .ab-snapshot-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px 16px;
  margin: 0 0 16px;
  padding: 0;
}

.page-about .ab-snapshot-list div {
  border-top: 1px solid var(--line-dark);
  padding-top: 8px;
}

.page-about .ab-snapshot-list dt {
  font-size: 12px;
  color: var(--ab-muted);
  letter-spacing: .04em;
}

.page-about .ab-snapshot-list dd {
  margin: 4px 0 0;
  font-size: 20px;
  font-weight: 700;
  color: var(--data);
}

.page-about .ab-snapshot-foot {
  margin: 0;
  font-size: 13px;
  line-height: 1.6;
  color: var(--ab-muted);
}

/* ---------- 区块骨架 ---------- */

.page-about .ab-section {
  padding: 46px 0;
  position: relative;
}

.page-about .ab-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 12px;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .16em;
  color: var(--data-deep);
}

.page-about .ab-eyebrow::before {
  content: "";
  width: 20px;
  height: 2px;
  background: var(--lava);
  flex: 0 0 auto;
}

.page-about .ab-section h2 {
  font-size: clamp(25px, 5.6vw, 40px);
  font-weight: 900;
  max-width: 20em;
}

.page-about .ab-sec-lead {
  margin: 14px 0 0;
  font-size: 15px;
  color: var(--ab-soft);
  max-width: 46em;
}

/* ---------- 品牌主张 ---------- */

.page-about .ab-section--claim {
  background: var(--cream);
}

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

.page-about .ab-claim-text p {
  font-size: 15px;
  color: var(--ab-soft);
  margin-top: 14px;
}

.page-about .ab-claim-figure {
  margin: 0;
  position: relative;
  isolation: isolate;
}

.page-about .ab-claim-figure::after {
  content: "";
  position: absolute;
  inset: 0;
  border: 2px solid var(--lava);
  transform: translate(12px, 12px);
  z-index: -1;
  pointer-events: none;
}

.page-about .ab-claim-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 10 / 7;
  object-fit: cover;
  border-radius: 2px;
  filter: saturate(.92) contrast(1.04);
}

.page-about .ab-points {
  list-style: none;
  margin: 20px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .ab-points li {
  position: relative;
  padding-left: 24px;
  font-size: 15px;
  line-height: 1.65;
  color: var(--ab-soft);
}

.page-about .ab-points li::before {
  content: "";
  position: absolute;
  left: 2px;
  top: .52em;
  width: 10px;
  height: 10px;
  background: var(--lava);
  transform: rotate(45deg);
}

/* ---------- 版本时间线 ---------- */

.page-about .ab-section--timeline {
  background: var(--cream-deep);
  clip-path: polygon(0 0, 100% 2.2vw, 100% 100%, 0 100%);
  padding-top: 56px;
}

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

.page-about .ab-timeline {
  position: relative;
  display: grid;
  gap: 16px;
  padding-bottom: 8px;
}

.page-about .ab-timeline::before {
  content: "";
  position: absolute;
  left: 19px;
  top: 10px;
  bottom: 10px;
  width: 2px;
  background: linear-gradient(180deg, var(--clay), var(--lava) 48%, var(--data));
  opacity: .45;
}

.page-about .ab-node {
  position: relative;
  background: var(--paper);
  border: 1px solid var(--line);
  border-left: 1px solid var(--line);
  border-top: 4px solid var(--clay);
  padding: 22px 18px 18px 44px;
  transition: border-color .18s var(--ease), box-shadow .18s var(--ease);
}

.page-about .ab-node::before {
  content: "";
  position: absolute;
  left: 13px;
  top: 26px;
  width: 13px;
  height: 13px;
  background: var(--char);
  border: 2px solid var(--lava);
  transform: rotate(45deg);
}

.page-about .ab-node:hover,
.page-about .ab-node:focus-within {
  border-color: var(--lava);
  box-shadow: 0 10px 22px rgba(26, 26, 26, .09);
}

.page-about .ab-node--2 {
  border-top-color: var(--track);
}

.page-about .ab-node--3 {
  border-top-color: var(--data);
  border-left-color: var(--lava);
}

.page-about .ab-node-ver {
  margin: 0;
  font-size: 15px;
  font-weight: 700;
  letter-spacing: .02em;
  color: var(--lava-deep);
}

.page-about .ab-node--3 .ab-node-ver {
  color: var(--data-deep);
}

.page-about .ab-node h3 {
  margin: 6px 0 10px;
  font-size: 19px;
  font-weight: 800;
}

.page-about .ab-node p {
  font-size: 14px;
  color: var(--ab-soft);
}

.page-about .ab-node-note {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
  margin: 12px 0 0;
  font-size: 13px;
  color: var(--ink-mute);
}

/* ---------- 测试版范围 ---------- */

.page-about .ab-section--range {
  background: var(--cream);
  padding-bottom: 56px;
}

.page-about .ab-range {
  display: grid;
  gap: 28px;
}

.page-about .ab-range-intro p {
  margin-top: 14px;
  font-size: 15px;
  color: var(--ab-soft);
}

.page-about .ab-range-links {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px;
  margin-top: 22px;
}

.page-about .ab-text-link {
  font-size: 14px;
  font-weight: 700;
  color: var(--data-deep);
  text-decoration: none;
  border-bottom: 2px solid var(--data);
  padding-bottom: 2px;
  transition: color .18s var(--ease), border-color .18s var(--ease);
}

.page-about .ab-text-link:hover,
.page-about .ab-text-link:focus-visible {
  color: var(--lava-deep);
  border-color: var(--lava);
}

.page-about .ab-counts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  margin: 0;
}

.page-about .ab-count {
  position: relative;
  overflow: hidden;
  background: var(--graph);
  color: var(--cream);
  padding: 16px 14px 18px;
  min-width: 0;
}

.page-about .ab-count::after {
  content: "";
  position: absolute;
  right: -16px;
  bottom: -20px;
  width: 52px;
  height: 52px;
  background: var(--lava);
  transform: rotate(45deg);
  opacity: .2;
}

.page-about .ab-count:nth-child(3n) {
  background: var(--char);
  box-shadow: inset 3px 0 0 var(--data);
}

.page-about .ab-count dt {
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--ab-muted);
}

.page-about .ab-count dd {
  margin: 8px 0 0;
}

.page-about .ab-count b {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(24px, 6.4vw, 34px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--data);
}

.page-about .ab-count span {
  display: block;
  margin-top: 8px;
  font-size: 12px;
  line-height: 1.55;
  color: var(--ab-muted);
}

/* ---------- 团队与协作 ---------- */

.page-about .ab-section--team {
  background: var(--char);
  color: var(--cream);
  padding: 52px 0;
}

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

.page-about .ab-team-figure {
  margin: 0;
  position: relative;
}

.page-about .ab-team-figure::after {
  content: "";
  position: absolute;
  left: -10px;
  top: -10px;
  width: 44px;
  height: 44px;
  border-top: 3px solid var(--clay);
  border-left: 3px solid var(--clay);
  pointer-events: none;
}

.page-about .ab-team-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  filter: saturate(.88) contrast(1.06) brightness(.94);
}

.page-about .ab-team .ab-eyebrow {
  color: var(--data);
}

.page-about .ab-team h2 {
  color: var(--paper);
}

.page-about .ab-team-text p {
  margin-top: 14px;
  font-size: 15px;
  color: var(--ab-muted);
}

.page-about .ab-team-list {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  display: grid;
  gap: 0;
  border-top: 1px solid var(--line-dark);
}

.page-about .ab-team-list li {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 11px 0;
  border-bottom: 1px solid var(--line-dark);
  font-size: 14px;
  color: var(--cream);
}

.page-about .ab-team-list .mono {
  font-family: var(--font-mono);
  font-size: 17px;
  font-weight: 700;
  color: var(--track);
  min-width: 3.4em;
}

.page-about .ab-team-note {
  margin-top: 18px;
  font-size: 13px;
  color: var(--clay);
}

/* ---------- 服务与响应 ---------- */

.page-about .ab-section--service {
  background: var(--cream);
}

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

.page-about .ab-service-text p {
  margin-top: 14px;
  font-size: 15px;
  color: var(--ab-soft);
}

.page-about .ab-service-text a {
  color: var(--data-deep);
  font-weight: 700;
  text-decoration: none;
  border-bottom: 2px solid rgba(31, 182, 166, .45);
  transition: border-color .18s var(--ease), color .18s var(--ease);
}

.page-about .ab-service-text a:hover,
.page-about .ab-service-text a:focus-visible {
  color: var(--lava-deep);
  border-color: var(--lava);
}

.page-about .ab-service-panel {
  background: var(--paper);
  border: 1px solid var(--line);
  border-top: 4px solid var(--lava);
  padding: 20px 18px 18px;
}

.page-about .ab-service-label {
  margin: 0 0 14px;
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--stone);
}

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

.page-about .ab-contact-lines li {
  display: grid;
  gap: 3px;
  padding-bottom: 12px;
  border-bottom: 1px dashed var(--line);
  font-size: 15px;
  color: var(--char);
  word-break: break-word;
}

.page-about .ab-contact-lines li:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}

.page-about .ab-contact-key {
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--ink-mute);
}

.page-about .ab-service-hint {
  margin: 16px 0 0;
  padding-top: 14px;
  border-top: 1px solid var(--line);
  font-size: 13px;
  line-height: 1.62;
  color: var(--ink-mute);
}

/* ---------- 响应式 ---------- */

@media (min-width: 720px) {
  .page-about .ab-section {
    padding: 60px 0;
  }

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

  .page-about .ab-claim-text p,
  .page-about .ab-range-intro p,
  .page-about .ab-team-text p,
  .page-about .ab-service-text p {
    font-size: 16px;
  }
}

@media (min-width: 900px) {
  .page-about .ab-hero {
    padding: 26px 0 66px;
  }

  .page-about .ab-hero-grid {
    grid-template-columns: minmax(0, 1.42fr) minmax(0, .82fr);
    gap: 52px;
    align-items: end;
  }

  .page-about .ab-hero-actions .btn {
    flex: 0 0 auto;
  }

  .page-about .ab-claim {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr);
    gap: 46px;
    align-items: center;
  }

  .page-about .ab-timeline {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 22px;
    padding-bottom: 66px;
  }

  .page-about .ab-timeline::before {
    left: 0;
    right: 0;
    top: 26px;
    bottom: auto;
    width: auto;
    height: 2px;
    background: linear-gradient(90deg, var(--clay), var(--lava) 50%, var(--data));
  }

  .page-about .ab-node {
    padding: 32px 22px 24px;
    border-top-width: 4px;
    border-left: 1px solid var(--line);
  }

  .page-about .ab-node::before {
    left: 24px;
    top: -9px;
  }

  .page-about .ab-node--2 {
    transform: translateY(28px);
  }

  .page-about .ab-node--3 {
    transform: translateY(56px);
  }

  .page-about .ab-range {
    grid-template-columns: minmax(0, .9fr) minmax(0, 1.1fr);
    gap: 44px;
    align-items: start;
  }

  .page-about .ab-team {
    grid-template-columns: minmax(0, .82fr) minmax(0, 1.18fr);
    gap: 44px;
    align-items: center;
  }

  .page-about .ab-service {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, .9fr);
    gap: 44px;
    align-items: start;
  }

  .page-about .ab-service-panel {
    padding: 24px 24px 22px;
  }
}

@media (min-width: 1180px) {
  .page-about .ab-hero h1 {
    max-width: 9em;
  }

  .page-about .ab-service-text p,
  .page-about .ab-team-text p {
    font-size: 17px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-node,
  .page-about .ab-text-link,
  .page-about .ab-service-text a {
    transition: none;
  }
}