.page-about {
  --about-rule: rgba(29, 74, 122, 0.18);
  --about-rule-strong: rgba(29, 74, 122, 0.44);
  --about-rail-w: 192px;
  --about-gap: clamp(28px, 4.5vw, 72px);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding-top: clamp(34px, 6vw, 76px);
  padding-bottom: 0;
  background:
    radial-gradient(ellipse at 88% 6%, rgba(0, 229, 255, 0.13), transparent 46%),
    radial-gradient(ellipse at 6% 96%, rgba(255, 107, 53, 0.10), transparent 48%),
    linear-gradient(180deg, #0B1F3A 0%, #0B1F3A 58%, #0A1B33 100%);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, rgba(29, 74, 122, 0.30) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(29, 74, 122, 0.30) 1px, transparent 1px);
  background-size: 84px 84px;
  -webkit-mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.8), transparent 76%);
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.8), transparent 76%);
  pointer-events: none;
}

.page-about .about-hero .container {
  position: relative;
  z-index: 1;
}

.page-about .about-hero .breadcrumbs {
  margin-bottom: clamp(26px, 4vw, 46px);
}

.page-about .hero-grid {
  row-gap: clamp(30px, 5vw, 54px);
  padding-bottom: clamp(44px, 7vw, 92px);
}

.page-about .hero-copy .eyebrow {
  color: var(--cyan);
}

.page-about .hero-copy .display {
  margin: 16px 0 20px;
  font-size: clamp(31px, 5.4vw, 62px);
  line-height: 1.08;
  letter-spacing: 0.005em;
  max-width: 12em;
  color: #FFFFFF;
}

.page-about .hero-copy .lead {
  margin: 0;
  max-width: 34em;
  font-size: clamp(15.5px, 1.5vw, 18px);
  line-height: 1.82;
  color: var(--text-dark);
}

.page-about .hero-actions {
  margin-top: clamp(26px, 3.4vw, 38px);
  gap: 12px;
  flex-wrap: wrap;
}

.page-about .hero-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  align-self: start;
  background: rgba(29, 74, 122, 0.6);
  border: 1px solid rgba(29, 74, 122, 0.6);
}

.page-about .fact-cell {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 20px 18px;
  background: var(--ink-800);
  min-width: 0;
}

.page-about .fact-num {
  font-size: clamp(24px, 3.2vw, 36px);
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--signal);
}

.page-about .fact-label {
  font-size: 12.5px;
  line-height: 1.55;
  letter-spacing: 0.02em;
  color: var(--text-dark-dim);
}

/* ---------- 主体骨架 ---------- */
.page-about .about-main {
  position: relative;
  padding-block: clamp(46px, 6.5vw, 92px) clamp(58px, 8vw, 120px);
}

.page-about .about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(22px, 3vw, 40px);
}

@media (min-width: 1000px) {
  .page-about .about-layout {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: var(--about-gap);
  }
}

/* ---------- 章节索引 ---------- */
.page-about .chapter-rail {
  min-width: 0;
}

@media (min-width: 1000px) {
  .page-about .chapter-rail {
    position: sticky;
    top: calc(var(--header-space) + 26px);
    align-self: start;
  }
}

.page-about .rail-label {
  margin: 0 0 12px;
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--mist);
}

.page-about .chapter-list {
  list-style: none;
  margin: 0;
  padding: 0 0 6px;
  display: flex;
  gap: 6px;
  overflow-x: auto;
  scrollbar-width: none;
  -webkit-overflow-scrolling: touch;
}

.page-about .chapter-list::-webkit-scrollbar {
  display: none;
}

.page-about .chapter-list a {
  display: block;
  white-space: nowrap;
  padding: 9px 15px;
  font-size: 13px;
  line-height: 1.4;
  color: var(--text-light-dim);
  text-decoration: none;
  background: #FFFFFF;
  border: 1px solid var(--about-rule);
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease), background 0.2s var(--ease);
}

.page-about .chapter-list a:hover {
  color: var(--ink-900);
  border-color: var(--rule-soft);
  background: #FFFFFF;
}

.page-about .chapter-list a:focus-visible {
  outline: 2px solid var(--ink-900);
  outline-offset: 2px;
  color: var(--ink-900);
}

@media (min-width: 1000px) {
  .page-about .chapter-list {
    flex-direction: column;
    gap: 0;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .chapter-list a {
    position: relative;
    padding: 11px 0 11px 18px;
    white-space: normal;
    background: transparent;
    border: 0;
    border-left: 1px solid var(--about-rule-strong);
  }

  .page-about .chapter-list a::before {
    content: "";
    position: absolute;
    left: -3px;
    top: 50%;
    width: 5px;
    height: 5px;
    margin-top: -2.5px;
    border-radius: 50%;
    background: var(--about-rule-strong);
    transition: background 0.2s var(--ease), transform 0.2s var(--ease);
  }

  .page-about .chapter-list a:hover,
  .page-about .chapter-list a:focus-visible {
    background: transparent;
    border-left-color: var(--cyan);
  }

  .page-about .chapter-list a:hover::before,
  .page-about .chapter-list a:focus-visible::before {
    background: var(--cyan);
    transform: scale(1.7);
  }
}

/* ---------- 内容流 ---------- */
.page-about .about-stream {
  min-width: 0;
}

.page-about .stream-block {
  position: relative;
  padding-block: clamp(36px, 5.4vw, 70px);
  border-top: 1px solid var(--about-rule);
}

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

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

.page-about .block-head {
  display: flex;
  align-items: baseline;
  gap: 14px;
  margin-bottom: 18px;
}

.page-about .block-index {
  flex: none;
  padding-top: 4px;
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--signal);
}

.page-about .block-head .h-section {
  margin: 0;
  color: var(--ink-900);
}

.page-about .block-lead {
  margin: 0 0 4px;
  max-width: 40em;
  font-size: 16px;
  line-height: 1.78;
  color: var(--text-light-dim);
}

.page-about .prose p {
  margin: 0 0 1.15em;
  max-width: 42em;
  font-size: 16.5px;
  line-height: 1.78;
  color: var(--text-light-dim);
}

.page-about .prose p:last-child {
  margin-bottom: 0;
}

/* ---------- 团队构成密度条 ---------- */
.page-about .density-chart {
  margin-top: 28px;
  padding: clamp(20px, 3vw, 28px);
  display: grid;
  gap: 16px;
  background: #FFFFFF;
  border: 1px solid var(--about-rule);
}

.page-about .density-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 7px;
}

@media (min-width: 560px) {
  .page-about .density-row {
    grid-template-columns: 100px minmax(0, 1fr);
    align-items: center;
    gap: 18px;
  }
}

.page-about .density-label {
  font-size: 13.5px;
  letter-spacing: 0.02em;
  color: var(--ink-900);
}

.page-about .density-track {
  display: block;
  height: 12px;
  border-radius: 2px;
  background: rgba(11, 31, 58, 0.07);
  overflow: hidden;
}

.page-about .density-fill {
  display: block;
  height: 100%;
  border-radius: 2px;
}

.page-about .density-fill--a {
  width: 42%;
  background: linear-gradient(90deg, #0096B4 0%, #00C9E6 100%);
}

.page-about .density-fill--b {
  width: 28%;
  background: linear-gradient(90deg, #33997A 0%, #5FE3B0 100%);
}

.page-about .density-fill--c {
  width: 30%;
  background: linear-gradient(90deg, #D64E2B 0%, #FF6B35 100%);
}

.page-about .density-note {
  margin: 2px 0 0;
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--mist);
}

/* ---------- 三支能力线 ---------- */
.page-about .lines-list {
  margin-top: 26px;
  border-top: 1px solid var(--about-rule);
}

.page-about .line-item {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 9px;
  padding: 24px 0;
  border-bottom: 1px solid var(--about-rule);
}

@media (min-width: 760px) {
  .page-about .line-item {
    grid-template-columns: 164px minmax(0, 1fr);
    gap: 30px;
    align-items: start;
    padding: 30px 0;
  }
}

.page-about .line-tag {
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--signal);
  padding-top: 5px;
}

.page-about .line-title {
  margin: 0 0 9px;
  font-size: clamp(16.5px, 1.6vw, 20px);
  font-weight: 650;
  line-height: 1.4;
  letter-spacing: 0.01em;
  color: var(--ink-900);
}

.page-about .line-body p {
  margin: 0;
  max-width: 40em;
  font-size: 15.5px;
  line-height: 1.76;
  color: var(--text-light-dim);
}

.page-about .line-figure,
.page-about .history-figure,
.page-about .eco-figure {
  margin: 32px 0 0;
}

.page-about .line-figure figcaption,
.page-about .eco-figure figcaption {
  margin-top: 12px;
  font-size: 11.5px;
  letter-spacing: 0.06em;
  color: var(--mist);
}

/* ---------- 发展历程 ---------- */
.page-about .timeline {
  position: relative;
  list-style: none;
  margin: 32px 0 0;
  padding: 0;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 8px;
  bottom: 14px;
  width: 1px;
  background: linear-gradient(180deg, var(--cyan) 0%, rgba(0, 229, 255, 0.28) 20%, var(--about-rule) 60%, rgba(29, 74, 122, 0.10) 100%);
}

.page-about .timeline-node {
  position: relative;
  padding: 0 0 30px 32px;
}

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

.page-about .timeline-node::before {
  content: "";
  position: absolute;
  left: 0;
  top: 6px;
  width: 11px;
  height: 11px;
  box-sizing: border-box;
  border: 2px solid var(--ink-700);
  border-radius: 50%;
  background: var(--fog);
  transition: border-color 0.22s var(--ease), box-shadow 0.22s var(--ease), transform 0.22s var(--ease);
}

.page-about .timeline-node:hover::before {
  border-color: var(--cyan);
  box-shadow: 0 0 0 4px rgba(0, 229, 255, 0.18);
  transform: scale(1.1);
}

.page-about .timeline-year {
  display: block;
  margin-bottom: 6px;
  font-size: 11.5px;
  letter-spacing: 0.08em;
  color: var(--signal);
}

.page-about .timeline-title {
  margin: 0 0 7px;
  font-size: 17px;
  font-weight: 650;
  line-height: 1.36;
  color: var(--ink-900);
}

.page-about .timeline-node p {
  margin: 0;
  max-width: 40em;
  font-size: 15.5px;
  line-height: 1.74;
  color: var(--text-light-dim);
}

/* ---------- 资质 ---------- */
.page-about .cred-grid {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
}

@media (min-width: 660px) {
  .page-about .cred-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 18px;
  }
}

.page-about .cred-card {
  position: relative;
  padding: 26px 24px 24px;
  background: #FFFFFF;
  border: 1px solid var(--about-rule);
  transition: transform 0.22s var(--ease), border-color 0.22s var(--ease), box-shadow 0.22s var(--ease);
}

.page-about .cred-card::after {
  content: "";
  position: absolute;
  top: -1px;
  right: -1px;
  width: 20px;
  height: 20px;
  background: linear-gradient(to bottom left, var(--fog) 0 46%, var(--about-rule) 46% 52%, transparent 52% 100%);
  pointer-events: none;
}

.page-about .cred-card:hover,
.page-about .cred-card:focus-within {
  transform: translateY(-2px);
  border-color: var(--rule-soft);
  box-shadow: 0 10px 26px rgba(11, 31, 58, 0.09);
}

.page-about .cred-code {
  display: block;
  margin-bottom: 12px;
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--mist);
}

.page-about .cred-card h3 {
  margin: 0 0 9px;
  font-size: 16.5px;
  font-weight: 650;
  line-height: 1.42;
  color: var(--ink-900);
}

.page-about .cred-card p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--text-light-dim);
}

/* ---------- 合作生态 ---------- */
.page-about .eco-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 28px;
  margin-top: 26px;
}

@media (min-width: 860px) {
  .page-about .eco-layout {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.92fr);
    gap: 38px;
    align-items: start;
  }
}

.page-about .eco-list {
  margin: 0;
  display: grid;
}

.page-about .eco-list dt {
  padding: 18px 0 7px;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--signal);
  border-top: 1px solid var(--about-rule);
}

.page-about .eco-list dt:first-of-type {
  padding-top: 0;
  border-top: 0;
}

.page-about .eco-list dd {
  margin: 0 0 20px;
  max-width: 38em;
  font-size: 15.5px;
  line-height: 1.76;
  color: var(--text-light-dim);
}

.page-about .eco-list dd:last-of-type {
  margin-bottom: 0;
}

.page-about .eco-figure {
  margin-top: 0;
}

/* ---------- 下一步确认 ---------- */
.page-about .stream-block--closing {
  border-top: 0;
  padding-top: clamp(34px, 4.6vw, 58px);
}

.page-about .closing-panel {
  position: relative;
  overflow: hidden;
  padding: clamp(28px, 4.6vw, 52px);
  background: linear-gradient(150deg, #0F2A4D 0%, #0B1F3A 62%);
  clip-path: polygon(0 0, calc(100% - 26px) 0, 100% 26px, 100% 100%, 0 100%);
}

.page-about .closing-panel::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, rgba(29, 74, 122, 0.55) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(29, 74, 122, 0.55) 1px, transparent 1px);
  background-size: 58px 58px;
  -webkit-mask-image: radial-gradient(ellipse at 96% 4%, #000 0%, transparent 68%);
  mask-image: radial-gradient(ellipse at 96% 4%, #000 0%, transparent 68%);
  opacity: 0.75;
  pointer-events: none;
}

.page-about .closing-panel > * {
  position: relative;
  z-index: 1;
}

.page-about .closing-code {
  display: inline-block;
  margin-bottom: 14px;
  padding: 4px 10px;
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--cyan);
  border: 1px solid rgba(0, 229, 255, 0.42);
}

.page-about .closing-title {
  margin: 0 0 14px;
  color: #FFFFFF;
  max-width: 16em;
}

.page-about .closing-lead {
  margin: 0;
  max-width: 40em;
  font-size: 16px;
  line-height: 1.8;
  color: var(--text-dark);
}

.page-about .closing-actions {
  margin-top: clamp(22px, 3vw, 32px);
  gap: 12px;
  flex-wrap: wrap;
}

/* ---------- 动效降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .cred-card,
  .page-about .timeline-node::before,
  .page-about .chapter-list a,
  .page-about .chapter-list a::before {
    transition: none;
  }

  .page-about .cred-card:hover {
    transform: none;
  }

  .page-about .timeline-node:hover::before {
    transform: none;
  }
}
</main>