.page-about {
  --about-hero-pad-top: calc(var(--header-h) + clamp(48px, 9vw, 118px));
  --about-rule: rgba(11, 13, 15, .12);
}

/* ============ 首屏 ============ */
.page-about .about-hero {
  padding-top: var(--about-hero-pad-top);
  padding-bottom: clamp(56px, 8vw, 108px);
}

.page-about .about-hero-inner {
  display: grid;
  gap: clamp(36px, 6vw, 72px);
  align-items: end;
}

.page-about .about-hero .crumbs {
  color: var(--text-dim);
  margin-bottom: clamp(20px, 3vw, 34px);
}

.page-about .about-eyebrow {
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--gold-300);
  margin: 0 0 18px;
}

.page-about .about-hero-title {
  font-size: clamp(32px, 7.4vw, 88px);
  line-height: 1.08;
  letter-spacing: -0.03em;
  color: var(--warm-050);
  margin: 0;
  max-width: 15ch;
}

.page-about .about-hero-lead {
  margin: clamp(24px, 3.4vw, 38px) 0 0;
  max-width: 58ch;
  color: var(--text-dim);
}

.page-about .about-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(26px, 3.6vw, 40px);
}

.page-about .about-hero-index {
  margin: 0;
  border-top: 1px solid var(--line-dark);
}

.page-about .about-idx-row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 18px;
  padding: 13px 0;
  border-bottom: 1px solid var(--line-dark);
}

.page-about .about-idx-row dt {
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--text-dim);
  white-space: nowrap;
}

.page-about .about-idx-row dd {
  margin: 0;
  font-size: 15px;
  font-weight: 600;
  color: var(--warm-050);
  text-align: right;
}

.page-about .about-idx-row dd .num {
  color: var(--gold-300);
  font-size: 17px;
}

/* ============ 主体三栏 ============ */
.page-about .about-body {
  padding-block: clamp(48px, 7vw, 96px) clamp(64px, 9vw, 128px);
}

.page-about .about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(30px, 4.5vw, 56px);
}

.page-about .about-rail {
  border-bottom: 1px solid var(--about-rule);
  padding-bottom: 18px;
}

.page-about .about-rail .rail-title {
  margin-bottom: 12px;
}

.page-about .about-rail .rail-list {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 18px;
}

.page-about .about-rail .rail-link {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  font-size: 14px;
  font-weight: 500;
  color: var(--graphite-600);
  padding: 4px 0;
  border-bottom: 1px solid transparent;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-rail .rail-link .mono {
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--gold-500);
}

.page-about .about-rail .rail-link:hover,
.page-about .about-rail .rail-link:focus-visible {
  color: var(--ink-950);
  border-bottom-color: var(--gold-500);
}

.page-about .about-main {
  min-width: 0;
}

/* ============ 章节 ============ */
.page-about .about-chapter {
  padding-block: clamp(34px, 5vw, 58px);
  border-top: 1px solid var(--about-rule);
}

.page-about .about-chapter:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .about-chapter .h2 {
  margin: 14px 0 clamp(20px, 2.6vw, 30px);
  max-width: 22ch;
  color: var(--ink-950);
}

.page-about .about-chapter .h3 {
  margin: 10px 0 8px;
  font-size: 17px;
  color: var(--ink-950);
}

.page-about .about-chapter .prose p {
  color: var(--graphite-600);
}

.page-about .about-tail {
  margin-top: clamp(22px, 3vw, 34px);
}

.page-about .about-tail a {
  color: var(--ink-950);
  border-bottom: 1px solid var(--gold-500);
  padding-bottom: 2px;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-tail a:hover,
.page-about .about-tail a:focus-visible {
  color: var(--signal-600);
  border-bottom-color: var(--signal-600);
}

/* ---- 三类内容能力 ---- */
.page-about .about-caps {
  list-style: none;
  margin: clamp(26px, 3.4vw, 40px) 0 0;
  padding: 0;
  display: grid;
  gap: 0;
}

.page-about .about-cap {
  padding: clamp(20px, 2.6vw, 28px) 0;
  border-top: 1px solid var(--about-rule);
}

.page-about .about-cap:last-child {
  border-bottom: 1px solid var(--about-rule);
}

.page-about .about-cap-no {
  display: inline-block;
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--gold-500);
  border: 1px solid var(--gold-300);
  border-radius: var(--r-pill);
  padding: 2px 12px;
}

.page-about .about-cap p {
  margin: 0;
  color: var(--graphite-600);
  max-width: 62ch;
}

/* ---- 版本脉络 ---- */
.page-about .about-trace-figure {
  margin: clamp(24px, 3vw, 36px) 0 10px;
}

.page-about .about-trace-figure img {
  border-radius: var(--r-lg);
}

.page-about .figure-caption {
  color: var(--gray-400);
  font-size: 12px;
  letter-spacing: .08em;
  margin: 0;
}

.page-about .about-milestones {
  list-style: none;
  margin: clamp(28px, 3.6vw, 42px) 0 0;
  padding: 0 0 0 30px;
  position: relative;
}

.page-about .about-milestones::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: linear-gradient(to bottom, var(--gold-500), var(--signal-300));
}

.page-about .about-milestone {
  position: relative;
  padding-bottom: clamp(20px, 2.6vw, 30px);
}

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

.page-about .about-milestone::before {
  content: "";
  position: absolute;
  left: -30px;
  top: 7px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--gold-500);
  box-shadow: 0 0 0 4px var(--warm-050);
}

.page-about .about-milestone-ver {
  margin: 0 0 6px;
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--ink-950);
  font-weight: 700;
}

.page-about .about-milestone-txt {
  margin: 0;
  color: var(--graphite-600);
  max-width: 62ch;
  line-height: 1.8;
}

/* ---- 团队流程 ---- */
.page-about .about-crew-figure {
  margin: clamp(26px, 3.4vw, 40px) 0 0;
}

.page-about .about-crew-figure img {
  border-radius: var(--r-lg);
}

.page-about .about-flow {
  list-style: none;
  margin: clamp(26px, 3.4vw, 38px) 0 0;
  padding: 0;
  display: grid;
  gap: 0;
}

.page-about .about-flow-step {
  padding: 18px 0;
  border-bottom: 1px solid var(--about-rule);
}

.page-about .about-flow-step:first-child {
  border-top: 1px solid var(--about-rule);
}

.page-about .about-flow-no {
  display: block;
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--celadon-600);
}

.page-about .about-flow-step .h3 {
  margin: 6px 0 6px;
}

.page-about .about-flow-step p {
  margin: 0;
  color: var(--graphite-600);
  max-width: 62ch;
}

/* ---- 生态 ---- */
.page-about .about-network-grid {
  display: grid;
  gap: clamp(24px, 3.4vw, 40px);
  margin-top: clamp(22px, 3vw, 34px);
}

.page-about .about-network-figure {
  margin: 0;
}

.page-about .about-network-figure img {
  border-radius: var(--r-lg);
}

.page-about .about-nodes {
  list-style: none;
  margin: clamp(28px, 3.6vw, 42px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 10px;
}

.page-about .about-node {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 14px;
  border: 1px solid var(--about-rule);
  border-radius: var(--r-md);
  font-size: 14px;
  color: var(--ink-950);
  background: var(--warm-050);
  transition: border-color var(--dur) var(--ease), background-color var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.page-about .about-node-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--celadon-600);
  flex: none;
  transition: background-color var(--dur) var(--ease);
}

.page-about .about-node-id {
  margin-left: auto;
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--gray-400);
}

.page-about .about-node:hover,
.page-about .about-node:focus-within {
  border-color: var(--gold-500);
  background: var(--paper-100);
  transform: translateY(-1px);
}

.page-about .about-node:hover .about-node-dot {
  background: var(--gold-500);
}

/* ---- 客户与场景 ---- */
.page-about .about-stats {
  margin: 0 0 clamp(26px, 3.4vw, 40px);
  display: grid;
  gap: 0;
}

.page-about .about-stat {
  padding: clamp(18px, 2.4vw, 26px) 0;
  border-bottom: 1px solid var(--about-rule);
}

.page-about .about-stat:first-child {
  border-top: 1px solid var(--about-rule);
}

.page-about .about-stat dt {
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--graphite-600);
}

.page-about .about-stat dd {
  margin: 6px 0 0;
  display: flex;
  align-items: baseline;
  gap: 8px;
}

.page-about .about-stat-num {
  font-size: clamp(36px, 6vw, 56px);
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--ink-950);
  line-height: 1;
}

.page-about .about-stat-unit {
  font-size: 14px;
  color: var(--gray-400);
}

.page-about .about-scenes {
  list-style: none;
  margin: clamp(24px, 3vw, 36px) 0 0;
  padding: 0;
  display: grid;
  gap: 0;
}

.page-about .about-scene {
  padding: clamp(20px, 2.6vw, 28px) 0;
  border-top: 1px solid var(--about-rule);
}

.page-about .about-scene:last-child {
  border-bottom: 1px solid var(--about-rule);
}

.page-about .about-scene-no {
  margin: 0;
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--signal-600);
}

.page-about .about-scene p {
  margin: 0;
  color: var(--graphite-600);
  max-width: 62ch;
}

/* ---- 站点信息 ---- */
.page-about .about-meta {
  margin: 0;
}

.page-about .about-meta .data-row {
  display: grid;
  grid-template-columns: minmax(100px, 140px) minmax(0, 1fr);
  gap: 12px;
  align-items: baseline;
  padding: 14px 0;
  border-bottom: 1px solid var(--about-rule);
}

.page-about .about-meta .data-row:first-child {
  border-top: 1px solid var(--about-rule);
}

.page-about .about-meta dt {
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--graphite-600);
}

.page-about .about-meta dd {
  margin: 0;
  font-size: 15px;
  color: var(--ink-950);
  word-break: break-word;
}

/* ============ 右栏 ============ */
.page-about .about-aside .aside-panel {
  border-radius: var(--r-lg);
  padding: clamp(20px, 2.6vw, 26px);
}

.page-about .about-aside .rail-title {
  margin: 0 0 14px;
}

.page-about .about-facts {
  margin: 0;
  display: grid;
  gap: 0;
}

.page-about .about-fact {
  padding: 14px 0;
  border-bottom: 1px solid var(--about-rule);
  transition: border-color var(--dur) var(--ease);
}

.page-about .about-fact:first-child {
  border-top: 1px solid var(--about-rule);
}

.page-about .about-fact dt {
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--gray-400);
}

.page-about .about-fact dd {
  margin: 6px 0 0;
  display: flex;
  align-items: baseline;
  gap: 6px;
  font-size: 14px;
  color: var(--ink-950);
}

.page-about .about-fact-num {
  font-size: clamp(26px, 3.4vw, 34px);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1;
  color: var(--ink-950);
}

.page-about .about-fact-note {
  margin: 6px 0 0;
  font-size: 12px;
  line-height: 1.6;
  color: var(--gray-400);
}

.page-about .about-fact:hover {
  border-color: var(--gold-500);
}

.page-about .about-fact:hover .about-fact-num {
  color: var(--gold-500);
}

.page-about .about-sync {
  margin: 18px 0 0;
}

.page-about .about-aside-cta {
  display: inline-flex;
  margin-top: 16px;
}

/* ============ 桌面栅格 ============ */
@media (min-width: 620px) {
  .page-about .about-stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 0 clamp(18px, 2.4vw, 32px);
  }

  .page-about .about-stat {
    border-bottom: 0;
    border-top: 1px solid var(--about-rule);
  }

  .page-about .about-cap {
    display: grid;
    grid-template-columns: auto minmax(0, 1fr);
    column-gap: 18px;
    align-items: start;
  }

  .page-about .about-cap .about-cap-no {
    grid-row: span 2;
  }

  .page-about .about-cap .h3 {
    margin-top: 2px;
  }

  .page-about .about-flow {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: clamp(20px, 3vw, 40px);
  }

  .page-about .about-flow-step:nth-child(2) {
    border-top: 1px solid var(--about-rule);
  }
}

@media (min-width: 900px) {
  .page-about .about-layout {
    grid-template-columns: 200px minmax(0, 1fr);
    align-items: start;
  }

  .page-about .about-rail {
    position: sticky;
    top: calc(var(--header-h) + 26px);
    border-bottom: 0;
    padding-bottom: 0;
  }

  .page-about .about-rail .rail-list {
    flex-direction: column;
    gap: 4px;
  }

  .page-about .about-network-grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.05fr);
    align-items: center;
  }

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

  .page-about .about-flow-step {
    border-top: 1px solid var(--about-rule);
    border-bottom: 0;
    padding-right: 18px;
  }

  .page-about .about-meta .data-row {
    grid-template-columns: 160px minmax(0, 1fr);
  }
}

@media (min-width: 1000px) {
  .page-about .about-hero-inner {
    grid-template-columns: minmax(0, 1.55fr) minmax(260px, .85fr);
  }
}

@media (min-width: 1180px) {
  .page-about .about-layout {
    grid-template-columns: 220px minmax(0, 1fr) 280px;
    gap: clamp(36px, 4vw, 56px);
  }

  .page-about .about-aside {
    position: sticky;
    top: calc(var(--header-h) + 26px);
    align-self: start;
  }
}

/* 窄屏无横向溢出 */
@media (max-width: 420px) {
  .page-about .about-hero-title {
    font-size: clamp(28px, 9.4vw, 40px);
  }

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

  .page-about .about-meta .data-row {
    grid-template-columns: minmax(0, 1fr);
    gap: 6px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-node,
  .page-about .about-fact,
  .page-about .about-fact-num,
  .page-about .about-rail .rail-link,
  .page-about .about-tail a {
    transition: none;
  }

  .page-about .about-node:hover {
    transform: none;
  }
}
<<<END>>>