.page-about {
  --ab-rail: 11px;
  --ab-rail-desktop: 79px;
  display: block;
}

/* 面包屑 */
.page-about .breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding: 26px 0 0;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--dim);
}

.page-about .breadcrumbs-link {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 140ms var(--ease);
}

.page-about .breadcrumbs-link:hover {
  border-bottom-color: var(--cyan);
}

/* 首屏 */
.page-about .ab-hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 30px;
  padding: 30px 0 0;
}

.page-about .ab-hero-copy h1 {
  margin: 14px 0 0;
  font-family: var(--sans);
  font-weight: 800;
  font-size: clamp(30px, 7.2vw, 56px);
  line-height: 1.1;
  letter-spacing: -0.02em;
  color: var(--paper);
  max-width: 20ch;
}

.page-about .ab-hero-copy .lede {
  margin-top: 18px;
  color: var(--text);
  max-width: 62ch;
}

.page-about .ab-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

.page-about .ab-hero-figure {
  position: relative;
  margin: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--ink-2);
  overflow: hidden;
}

.page-about .ab-hero-figure::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(118deg, rgba(56, 225, 196, 0.14), rgba(56, 225, 196, 0) 58%);
  pointer-events: none;
}

.page-about .ab-hero-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 12 / 7;
  object-fit: cover;
}

/* 首屏数据带 */
.page-about .ab-stats {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 34px 0 0;
  padding: 0;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .ab-stat {
  padding: 18px 16px 20px;
  background: var(--ink-2);
}

.page-about .ab-stat-num {
  display: block;
  font-family: var(--mono);
  font-weight: 700;
  font-size: clamp(22px, 4.4vw, 32px);
  line-height: 1;
  letter-spacing: -0.04em;
  color: var(--cyan);
}

.page-about .ab-stat-label {
  display: block;
  margin-top: 10px;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--dim);
}

/* 纵向时间线主线 */
.page-about .ab-flow {
  position: relative;
  margin-top: 48px;
}

.page-about .ab-flow::before {
  content: "";
  position: absolute;
  left: var(--ab-rail);
  top: 10px;
  bottom: 10px;
  width: 1px;
  background: linear-gradient(180deg, rgba(56, 225, 196, 0.6), rgba(56, 225, 196, 0.14) 68%, rgba(56, 225, 196, 0));
}

.page-about .ab-step {
  position: relative;
  padding: 34px 0 34px 38px;
}

.page-about .ab-step::before {
  content: "";
  position: absolute;
  left: calc(var(--ab-rail) - 6px);
  top: 42px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--ink);
  border: 1px solid var(--cyan);
  box-shadow: 0 0 0 4px rgba(56, 225, 196, 0.1);
  transition: box-shadow 160ms var(--ease), background 160ms var(--ease);
}

.page-about .ab-step:hover::before {
  background: var(--cyan);
  box-shadow: 0 0 0 6px rgba(56, 225, 196, 0.18);
}

.page-about .ab-step-head {
  display: flex;
  align-items: flex-start;
  gap: 14px;
}

.page-about .ab-step-num {
  flex: 0 0 auto;
  font-family: var(--mono);
  font-weight: 700;
  font-size: clamp(26px, 5.4vw, 42px);
  line-height: 0.92;
  letter-spacing: -0.04em;
  color: var(--orange);
}

.page-about .ab-step-titlebox {
  min-width: 0;
  padding-top: 2px;
}

.page-about .ab-step-titlebox .section-title {
  margin: 0;
  font-size: clamp(21px, 3.2vw, 30px);
  line-height: 1.25;
  color: var(--paper);
}

.page-about .ab-step-meta {
  margin: 6px 0 0;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--dim);
}

.page-about .ab-step-body {
  margin-top: 18px;
  color: var(--text);
  font-size: 16px;
  line-height: 1.75;
}

.page-about .ab-step-body p {
  max-width: 68ch;
  margin: 0 0 0.9em;
}

.page-about .ab-step-body p:last-child {
  margin-bottom: 0;
}

/* 四条内容线 */
.page-about .ab-lines {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .ab-line {
  padding: 14px 16px;
  border-left: 2px solid var(--line);
  background: var(--panel-soft);
  border-radius: 0 var(--radius) var(--radius) 0;
  transition: border-color 150ms var(--ease), background 150ms var(--ease);
}

.page-about .ab-line:hover {
  border-left-color: var(--cyan);
  background: var(--panel);
}

.page-about .ab-line-name {
  margin: 0 0 4px;
  font-size: 15px;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--paper);
}

.page-about .ab-line p {
  margin: 0;
  font-size: 15px;
  color: var(--dim);
  line-height: 1.7;
}

/* 版本节点 */
.page-about .ab-track {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .ab-track-item {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 8px;
  padding: 16px 18px;
  background: var(--panel-soft);
  transition: background 150ms var(--ease);
}

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

.page-about .ab-track-ver {
  font-family: var(--mono);
  font-weight: 700;
  font-size: 17px;
  letter-spacing: -0.02em;
  color: var(--cyan);
}

.page-about .ab-track-text {
  margin: 0;
  font-size: 15px;
  line-height: 1.7;
  color: var(--dim);
}

.page-about .ab-track-item--now {
  background: rgba(255, 122, 47, 0.08);
  box-shadow: inset 3px 0 0 var(--orange);
}

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

.page-about .ab-track-item--now .ab-track-text {
  color: var(--text);
}

/* 团队 */
.page-about .ab-team {
  display: grid;
  gap: 22px;
  margin-top: 22px;
}

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

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

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

.page-about .ab-team-item {
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr);
  gap: 14px;
  align-items: start;
  padding: 14px 0;
  border-top: 1px solid var(--line);
}

.page-about .ab-team-count {
  font-family: var(--mono);
  font-weight: 700;
  font-size: 26px;
  line-height: 1;
  letter-spacing: -0.04em;
  color: var(--orange);
}

.page-about .ab-team-name {
  margin: 0 0 4px;
  font-size: 15px;
  font-weight: 800;
  color: var(--paper);
}

.page-about .ab-team-item p {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--dim);
}

/* 更新节奏 */
.page-about .ab-cadence {
  margin: 22px 0 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.page-about .ab-cadence-row {
  display: grid;
  gap: 6px;
  padding: 15px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .ab-cadence-row dt {
  font-family: var(--mono);
  font-weight: 700;
  font-size: 15px;
  letter-spacing: -0.01em;
  color: var(--cyan);
}

.page-about .ab-cadence-row dd {
  margin: 0;
  font-size: 15px;
  line-height: 1.7;
  color: var(--dim);
}

/* 长期承诺 */
.page-about .ab-promise {
  display: grid;
  gap: 16px;
  margin-top: 22px;
}

.page-about .ab-promise-item {
  padding: 20px 18px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: transform 160ms var(--ease), border-color 160ms var(--ease);
}

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

.page-about .ab-promise-title {
  margin: 0 0 8px;
  font-size: 16px;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--paper);
}

.page-about .ab-promise-item p {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--dim);
}

/* 内容规模 */
.page-about .ab-scale {
  margin-top: 56px;
  padding-top: 34px;
  border-top: 1px solid var(--line);
}

.page-about .ab-scale-head .section-title {
  margin: 8px 0 0;
  font-size: clamp(22px, 3.4vw, 32px);
  color: var(--paper);
}

.page-about .ab-scale-head .section-note {
  margin: 10px 0 0;
  max-width: 60ch;
  color: var(--dim);
}

.page-about .ab-scale-figure {
  margin: 24px 0 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--ink-2);
  overflow: hidden;
}

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

.page-about .ab-bars {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .ab-bar-link {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 4px 14px;
  padding: 12px 14px;
  background: var(--panel-soft);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  text-decoration: none;
  transition: border-color 150ms var(--ease), background 150ms var(--ease);
}

.page-about .ab-bar-link:hover {
  border-color: var(--cyan);
  background: var(--panel);
}

.page-about .ab-bar-name {
  font-size: 16px;
  font-weight: 800;
  color: var(--paper);
}

.page-about .ab-bar-num {
  font-family: var(--mono);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--orange);
}

.page-about .ab-bar-fill {
  grid-column: 1 / -1;
  display: block;
  height: 4px;
  border-radius: 2px;
  background: linear-gradient(90deg, var(--cyan), rgba(56, 225, 196, 0.12));
}

.page-about .ab-bar:nth-child(1) .ab-bar-fill { width: 100%; }
.page-about .ab-bar:nth-child(2) .ab-bar-fill { width: 63%; }
.page-about .ab-bar:nth-child(3) .ab-bar-fill { width: 70%; }
.page-about .ab-bar:nth-child(4) .ab-bar-fill { width: 52%; }

/* 结尾行动区 */
.page-about .ab-cta {
  margin-top: 48px;
  padding: 28px 20px;
  display: grid;
  gap: 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(135deg, var(--panel) 0%, var(--ink-2) 100%);
}

.page-about .ab-cta-copy .section-title {
  margin: 0;
  font-size: clamp(20px, 3vw, 28px);
  color: var(--paper);
}

.page-about .ab-cta-copy p {
  margin: 10px 0 0;
  color: var(--dim);
  font-size: 15px;
}

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

/* 平板及以上 */
@media (min-width: 640px) {
  .page-about .ab-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .ab-track-item {
    grid-template-columns: 118px minmax(0, 1fr);
    align-items: baseline;
    gap: 20px;
  }

  .page-about .ab-cadence-row {
    grid-template-columns: 156px minmax(0, 1fr);
    gap: 24px;
    align-items: baseline;
  }

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

/* 桌面端 */
@media (min-width: 1024px) {
  .page-about .ab-hero {
    grid-template-columns: minmax(0, 1.12fr) minmax(0, 1fr);
    gap: 52px;
    align-items: center;
    padding-top: 52px;
  }

  .page-about .ab-stats {
    margin-top: 46px;
  }

  .page-about .ab-flow {
    margin-top: 64px;
  }

  .page-about .ab-flow::before {
    left: var(--ab-rail-desktop);
  }

  .page-about .ab-step {
    padding: 54px 0 54px 130px;
  }

  .page-about .ab-step::before {
    left: calc(var(--ab-rail-desktop) - 6px);
    top: 66px;
  }

  .page-about .ab-step-body {
    margin-left: 56px;
  }

  .page-about .ab-team {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.05fr);
    gap: 34px;
    align-items: start;
  }

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

  .page-about .ab-scale {
    margin-top: 76px;
    padding-top: 44px;
  }

  .page-about .ab-cta {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    padding: 34px 38px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-line,
  .page-about .ab-track-item,
  .page-about .ab-promise-item,
  .page-about .ab-bar-link,
  .page-about .ab-step::before {
    transition: none;
  }

  .page-about .ab-promise-item:hover {
    transform: none;
  }
}