.page-about {
  --ab-gap: clamp(20px, 3vw, 36px);
  --ab-line-soft: rgba(159, 177, 193, 0.32);
  --ab-cyan-wash: rgba(56, 225, 255, 0.08);
  padding-bottom: calc(var(--quick-h) + 40px);
}

.page-about .breadcrumb {
  padding-top: clamp(18px, 3vw, 28px);
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  padding-block: clamp(20px, 4vw, 44px) clamp(28px, 4.5vw, 56px);
}

.page-about .ab-hero h1 {
  margin: 12px 0 0;
  font-family: var(--font-sans);
  font-weight: 900;
  font-size: clamp(2rem, 6.2vw, 4.2rem);
  line-height: 1.04;
  letter-spacing: -0.02em;
  color: var(--paper);
  max-width: 19ch;
}

.page-about .ab-h1-mark {
  background-image: linear-gradient(transparent 64%, rgba(56, 225, 255, 0.3) 64%);
  background-repeat: no-repeat;
  padding-bottom: 2px;
}

.page-about .ab-lede {
  margin: 20px 0 0;
  max-width: 62ch;
  color: var(--mist);
  font-size: clamp(1rem, 1.35vw, 1.0625rem);
  line-height: 1.78;
}

.page-about .ab-hero .stat-chips {
  margin-top: clamp(24px, 3.5vw, 36px);
}

/* ---------- 通用标题 ---------- */
.page-about .ab-h2 {
  margin: 10px 0 0;
  font-family: var(--font-sans);
  font-weight: 900;
  font-size: clamp(1.45rem, 3.6vw, 2.4rem);
  line-height: 1.14;
  letter-spacing: -0.015em;
  color: var(--paper);
  max-width: 20ch;
}

.page-about .ab-figure {
  margin: clamp(22px, 3.6vw, 36px) 0 0;
}

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

/* ---------- 版本轨道 ---------- */
.page-about .ab-vtrack {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 3vw, 32px);
  margin-top: clamp(26px, 4vw, 44px);
}

.page-about .ab-vrail {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 4px 6px;
  padding: 0 0 14px;
  border-bottom: 1px solid var(--line);
}

.page-about .ab-vrail-title {
  width: 100%;
  margin-bottom: 4px;
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--mist);
  opacity: 0.75;
}

.page-about .ab-vtick {
  display: inline-flex;
  align-items: baseline;
  gap: 6px;
  padding: 5px 10px;
  color: var(--mist);
  text-decoration: none;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  background: transparent;
  transition: color 160ms var(--ease), background-color 160ms var(--ease), border-color 160ms var(--ease);
}

.page-about .ab-vtick-num {
  font-weight: 700;
  color: var(--paper);
}

.page-about .ab-vtick:hover,
.page-about .ab-vtick:focus-visible {
  color: var(--cyan);
  background: var(--ab-cyan-wash);
  outline: none;
}

.page-about .ab-vtick:focus-visible {
  box-shadow: 0 0 0 2px var(--cyan);
}

.page-about .ab-vtick:hover .ab-vtick-num,
.page-about .ab-vtick:focus-visible .ab-vtick-num {
  color: var(--cyan);
}

.page-about .ab-vbody {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: clamp(16px, 2.4vw, 26px);
  min-width: 0;
}

.page-about .ab-vitem {
  position: relative;
  padding: clamp(16px, 2.2vw, 24px) 0 clamp(16px, 2.2vw, 24px) clamp(14px, 2vw, 26px);
  border-top: 1px solid var(--line);
  scroll-margin-top: calc(var(--strip-h) + 40px);
  transition: border-color 200ms var(--ease);
}

.page-about .ab-vitem::before {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: 2px;
  background: transparent;
  transition: background-color 220ms var(--ease);
}

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

.page-about .ab-vitem:target::before {
  background: linear-gradient(180deg, var(--cyan), rgba(56, 225, 255, 0));
}

.page-about .ab-vitem-head {
  display: flex;
  align-items: baseline;
  gap: 12px;
  margin: 0 0 8px;
  flex-wrap: wrap;
}

.page-about .ab-vnum {
  font-family: var(--font-sans);
  font-weight: 900;
  font-size: clamp(1.9rem, 5vw, 3rem);
  line-height: 0.9;
  letter-spacing: -0.02em;
  color: var(--ab-line-soft);
  transition: color 220ms var(--ease);
}

.page-about .ab-vitem:target .ab-vnum,
.page-about .ab-vitem:last-child .ab-vnum {
  color: var(--cyan);
}

.page-about .ab-vtag {
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--mist);
  padding: 2px 7px;
  border: 1px solid var(--line);
}

.page-about .ab-vtitle {
  margin: 0 0 8px;
  font-size: clamp(1.1rem, 2.1vw, 1.4rem);
  font-weight: 800;
  line-height: 1.32;
  color: var(--paper);
  letter-spacing: -0.01em;
}

.page-about .ab-vtext {
  margin: 0;
  max-width: 56ch;
  color: var(--mist);
  font-size: 0.98rem;
  line-height: 1.76;
}

/* ---------- 团队 ---------- */
.page-about .ab-bars {
  list-style: none;
  margin: clamp(22px, 3.6vw, 34px) 0 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.page-about .ab-bar {
  padding: 18px 18px 20px;
  background: var(--ink-800);
  border-left: 3px solid var(--line);
  min-width: 0;
  transition: transform 200ms var(--ease), background-color 200ms var(--ease), border-left-color 200ms var(--ease);
}

.page-about .ab-bar--content { border-left-color: var(--cyan); }
.page-about .ab-bar--product { border-left-color: var(--orange); }
.page-about .ab-bar--service { border-left-color: var(--lime); }

.page-about .ab-bar:hover,
.page-about .ab-bar:focus-within {
  background: var(--panel-700);
  transform: translateY(-3px);
}

.page-about .ab-bar-num {
  display: block;
  font-family: var(--font-sans);
  font-weight: 900;
  font-size: clamp(1.9rem, 4.2vw, 2.6rem);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--paper);
}

.page-about .ab-bar-name {
  display: block;
  margin-top: 6px;
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--cyan);
  letter-spacing: 0.01em;
}

.page-about .ab-bar-desc {
  margin: 10px 0 0;
  font-size: 0.92rem;
  line-height: 1.7;
  color: var(--mist);
}

/* ---------- 数据来源 ---------- */
.page-about .ab-nodes {
  list-style: none;
  margin: clamp(22px, 3.6vw, 34px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .ab-node {
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-height: 78px;
  padding: 12px 10px;
  background: var(--ink-900);
  transition: background-color 180ms var(--ease);
}

.page-about .ab-node:hover,
.page-about .ab-node:focus-within {
  background: var(--panel-700);
}

.page-about .ab-node-num {
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--cyan);
}

.page-about .ab-node-name {
  font-size: 0.82rem;
  line-height: 1.4;
  color: var(--mist);
}

.page-about .ab-node:hover .ab-node-name {
  color: var(--paper);
}

.page-about .ab-note {
  margin: clamp(20px, 3vw, 30px) 0 0;
  max-width: 64ch;
  padding-left: 16px;
  border-left: 2px solid var(--line);
  color: var(--mist);
  font-size: 0.95rem;
  line-height: 1.78;
}

/* ---------- 评估信号 ---------- */
.page-about .ab-signals {
  list-style: none;
  margin: clamp(24px, 3.8vw, 38px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(18px, 2.6vw, 28px);
}

.page-about .ab-signal {
  padding: 18px 0 0;
  border-top: 1px solid var(--line);
}

.page-about .ab-signal-k {
  display: block;
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--mist);
}

.page-about .ab-signal-v {
  display: block;
  margin: 8px 0 0;
  font-family: var(--font-sans);
  font-weight: 900;
  font-size: clamp(2.1rem, 5.4vw, 3.2rem);
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--paper);
}

.page-about .ab-signal-u {
  margin-left: 4px;
  font-size: 0.42em;
  font-weight: 700;
  color: var(--cyan);
}

.page-about .ab-signal-d {
  margin: 12px 0 0;
  max-width: 40ch;
  font-size: 0.92rem;
  line-height: 1.72;
  color: var(--mist);
}

/* ---------- 下一步 ---------- */
.page-about .ab-road {
  list-style: none;
  margin: clamp(24px, 3.8vw, 38px) 0 0;
  padding: 0;
  display: grid;
  gap: 2px;
  background: var(--line);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.page-about .ab-road-item {
  display: flex;
  gap: clamp(14px, 2.4vw, 24px);
  padding: clamp(16px, 2.4vw, 24px) clamp(12px, 2vw, 20px);
  background: var(--ink-800);
  transition: background-color 180ms var(--ease);
}

.page-about .ab-road-item:hover {
  background: var(--panel-700);
}

.page-about .ab-road-num {
  flex: 0 0 auto;
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--cyan);
  padding-top: 4px;
}

.page-about .ab-road-body {
  min-width: 0;
}

.page-about .ab-road-title {
  margin: 0 0 8px;
  font-size: clamp(1rem, 1.8vw, 1.2rem);
  font-weight: 800;
  line-height: 1.35;
  color: var(--paper);
}

.page-about .ab-road-body p {
  margin: 0;
  max-width: 58ch;
  font-size: 0.93rem;
  line-height: 1.74;
  color: var(--mist);
}

/* ---------- 结尾入口 ---------- */
.page-about .ab-cta {
  margin-top: clamp(28px, 4.2vw, 44px);
  padding-top: clamp(20px, 3vw, 28px);
  border-top: 1px solid var(--line);
}

.page-about .ab-cta-text {
  margin: 0 0 18px;
  max-width: 46ch;
  font-size: clamp(1rem, 1.8vw, 1.12rem);
  font-weight: 700;
  line-height: 1.6;
  color: var(--paper);
}

.page-about .ab-cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

/* ---------- 桌面端 ---------- */
@media (min-width: 768px) {
  .page-about .ab-bars {
    flex-direction: row;
    align-items: stretch;
    gap: 8px;
  }

  .page-about .ab-bar--content { flex: 0 0 38%; }
  .page-about .ab-bar--product { flex: 0 0 45%; }
  .page-about .ab-bar--service { flex: 0 0 15%; }

  .page-about .ab-bar--service .ab-bar-desc {
    font-size: 0.84rem;
  }

  .page-about .ab-node {
    min-height: 92px;
    padding: 14px 14px;
  }

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

@media (min-width: 860px) {
  .page-about .ab-signals {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: clamp(22px, 3vw, 34px) clamp(28px, 4vw, 52px);
  }

  .page-about .ab-signal:nth-child(even) {
    transform: translateY(clamp(14px, 2.6vw, 30px));
  }
}

@media (min-width: 900px) {
  .page-about .ab-vtrack {
    grid-template-columns: 152px minmax(0, 1fr);
    gap: clamp(32px, 5vw, 68px);
    align-items: start;
  }

  .page-about .ab-vrail {
    position: sticky;
    top: calc(var(--strip-h) + 28px);
    flex-direction: column;
    flex-wrap: nowrap;
    align-items: stretch;
    gap: 0;
    padding: 0;
    border-bottom: 0;
    border-left: 1px solid var(--line);
  }

  .page-about .ab-vrail-title {
    padding: 0 0 10px 14px;
    margin: 0;
  }

  .page-about .ab-vtick {
    padding: 9px 0 9px 14px;
    margin-left: -1px;
    border-left: 2px solid transparent;
    justify-content: flex-start;
  }

  .page-about .ab-vtick:hover,
  .page-about .ab-vtick:focus-visible {
    border-left-color: var(--cyan);
    background: var(--ab-cyan-wash);
  }

  .page-about .ab-vitem {
    padding-right: clamp(0px, 2vw, 28px);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-vtick,
  .page-about .ab-vnum,
  .page-about .ab-vitem,
  .page-about .ab-vitem::before,
  .page-about .ab-bar,
  .page-about .ab-node,
  .page-about .ab-road-item {
    transition: none;
  }

  .page-about .ab-bar:hover,
  .page-about .ab-bar:focus-within {
    transform: none;
  }

  .page-about .ab-signal:nth-child(even) {
    transform: none;
  }
}
<<<END>>>