.page-about {
  --about-cut: 14px;
  --about-gap: clamp(52px, 6.5vw, 88px);
  background: var(--night-900);
  color: var(--snow);
}

/* ---------- 面包屑 ---------- */
.page-about .about-crumbs {
  padding-top: 26px;
  padding-bottom: 4px;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  isolation: isolate;
  padding: clamp(34px, 5vw, 62px) 0 clamp(44px, 6vw, 76px);
}
.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: -30% -8% auto -8%;
  height: 560px;
  z-index: -1;
  pointer-events: none;
  background:
    radial-gradient(58% 78% at 80% 16%, rgba(43, 227, 199, 0.18), transparent 62%),
    radial-gradient(44% 58% at 10% -4%, rgba(242, 179, 61, 0.15), transparent 66%),
    linear-gradient(180deg, rgba(22, 36, 74, 0.85), transparent 88%);
}
.page-about .hero-glyph {
  position: absolute;
  top: clamp(10px, 3vw, 34px);
  right: max(16px, calc((100% - var(--shell)) / 2));
  z-index: 0;
  margin: 0;
  font-size: clamp(50px, 10vw, 138px);
  font-weight: 700;
  line-height: 0.78;
  letter-spacing: -0.04em;
  color: var(--night-600);
  opacity: 0.7;
  pointer-events: none;
  user-select: none;
}
.page-about .about-hero-inner {
  position: relative;
  z-index: 1;
}
.page-about .about-hero-title {
  margin: 16px 0 0;
  max-width: 15em;
  font-size: clamp(32px, 5.6vw, 64px);
  line-height: 1.04;
  letter-spacing: -0.03em;
}
.page-about .hero-em {
  color: var(--cyan);
}
.page-about .about-hero-lede {
  margin-top: 22px;
  max-width: 62ch;
  color: var(--mist);
}
.page-about .hero-facts {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 0;
  margin: 34px 0 0;
  padding: 18px 0 0;
  list-style: none;
  border-top: 1px solid var(--steel);
}
.page-about .hero-facts li {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 0 26px;
  border-left: 1px solid var(--steel);
}
.page-about .hero-facts li:first-child {
  padding-left: 0;
  border-left: 0;
}
.page-about .fact-num {
  font-size: 24px;
  font-weight: 700;
  line-height: 1;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}
.page-about .fact-label {
  font-size: 13px;
  color: var(--mist);
}

/* ---------- 章节锚点导航 ---------- */
.page-about .about-toc {
  position: sticky;
  top: 0;
  z-index: 30;
  background: rgba(6, 11, 27, 0.92);
  border-top: 1px solid var(--steel);
  border-bottom: 1px solid var(--steel);
  backdrop-filter: blur(10px);
}
.page-about .toc-list {
  display: flex;
  gap: 6px;
  margin: 0;
  padding: 10px 0;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: none;
}
.page-about .toc-list::-webkit-scrollbar {
  display: none;
}
.page-about .toc-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px 14px;
  white-space: nowrap;
  font-size: 14px;
  color: var(--mist);
  text-decoration: none;
  border: 1px solid transparent;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease), background-color 0.2s var(--ease);
}
.page-about .toc-link .mono {
  font-size: 12px;
  color: var(--steel);
}
.page-about .toc-link:hover,
.page-about .toc-link:focus-visible {
  color: var(--snow);
  border-color: var(--steel);
  background: var(--night-600);
}
.page-about .toc-link:hover .mono,
.page-about .toc-link:focus-visible .mono {
  color: var(--cyan);
}

/* ---------- 通用章节 ---------- */
.page-about .about-sec {
  padding: var(--about-gap) 0;
  scroll-margin-top: 78px;
}
.page-about .sec-head {
  display: flex;
  align-items: center;
  gap: 14px;
  width: var(--sec-w, 100%);
  max-width: 100%;
  margin-bottom: 26px;
  padding: 15px 22px;
  background: linear-gradient(100deg, var(--night-600), rgba(22, 36, 74, 0.28));
  border-left: 3px solid var(--cyan);
  clip-path: polygon(0 0, calc(100% - var(--about-cut)) 0, 100% var(--about-cut), 100% 100%, 0 100%);
}
.page-about .sec-num {
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--gold);
}
.page-about .sec-title {
  margin: 0;
  font-size: clamp(20px, 2.6vw, 28px);
  line-height: 1.25;
  letter-spacing: -0.02em;
  color: var(--snow);
}
.page-about .prose {
  margin: 0 0 16px;
  max-width: 68ch;
  font-size: 16px;
  line-height: 1.75;
  color: var(--mist);
}
.page-about .about-grid {
  margin-top: 6px;
}

/* ---------- 首章数据面板 ---------- */
.page-about .fact-panel {
  padding: 20px 22px;
}
.page-about .fact-panel-title {
  margin: 0 0 14px;
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--cyan);
  text-transform: uppercase;
}
.page-about .fact-panel-list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 12px;
}
.page-about .fact-panel-list li {
  padding-top: 12px;
  border-top: 1px solid var(--steel);
  font-size: 14px;
  line-height: 1.6;
  color: var(--mist);
}
.page-about .fact-panel-list li .mono {
  display: inline-block;
  margin-right: 0.35em;
  font-size: 18px;
  font-weight: 700;
  color: var(--snow);
  font-variant-numeric: tabular-nums;
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: 28px 0 0;
}
.page-about .about-figure img {
  width: 100%;
  height: auto;
  object-fit: cover;
}
.page-about .tl-banner {
  margin: 22px 0 34px;
}

/* ---------- 青训章节（浅色断点） ---------- */
.page-about .about-sec--cream {
  background: linear-gradient(180deg, var(--cream), #dde5f6);
  color: var(--night-900);
}
.page-about .about-sec--cream .sec-head {
  background: rgba(6, 11, 27, 0.07);
  border-left-color: var(--gold-deep);
}
.page-about .about-sec--cream .sec-title {
  color: var(--night-900);
}
.page-about .about-sec--cream .sec-num {
  color: var(--gold-deep);
}
.page-about .about-sec--cream .prose {
  color: #22304c;
}
.page-about .about-sec--cream .media-caption {
  color: #4a5878;
}
.page-about .tier-lede {
  margin-bottom: 24px;
  font-size: 17px;
  font-weight: 500;
  color: var(--night-800);
  max-width: 60ch;
}

/* ---------- 栏位示意 ---------- */
.page-about .colmock {
  margin: 0;
  background: var(--night-900);
  border: 1px solid var(--steel);
  clip-path: polygon(0 0, calc(100% - 18px) 0, 100% 18px, 100% 100%, 0 100%);
  overflow: hidden;
}
.page-about .colmock-bar {
  display: flex;
  align-items: center;
  gap: 7px;
  padding: 10px 14px;
  background: var(--night-600);
  border-bottom: 1px solid var(--steel);
}
.page-about .colmock-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--steel);
}
.page-about .colmock-dot:first-child {
  background: var(--gold-deep);
}
.page-about .colmock-path {
  margin-left: 10px;
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--mist);
}
.page-about .colmock-body {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  padding: 1px;
  background: var(--steel);
}
.page-about .colmock-col {
  padding: 16px 16px 18px;
  background: var(--night-900);
  transition: background-color 0.24s var(--ease);
}
.page-about .colmock-col--2 {
  background: linear-gradient(158deg, rgba(43, 227, 199, 0.18), rgba(43, 227, 199, 0.04));
  box-shadow: inset 0 0 0 1px rgba(43, 227, 199, 0.45);
}
.page-about .colmock-col--3 {
  grid-column: 1 / -1;
}
.page-about .colmock-label {
  display: block;
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--gold);
}
.page-about .colmock-desc {
  margin: 8px 0 0;
  font-size: 14px;
  line-height: 1.55;
  color: var(--snow);
}
.page-about .colmock-hint {
  margin: 0;
  max-height: 0;
  opacity: 0;
  overflow: hidden;
  font-size: 13px;
  line-height: 1.6;
  color: var(--cyan-soft);
  transition: max-height 0.28s var(--ease), opacity 0.28s var(--ease), margin-top 0.28s var(--ease);
}
.page-about .colmock-col--2:hover .colmock-hint,
.page-about .colmock-col--2:focus-within .colmock-hint {
  max-height: 96px;
  margin-top: 8px;
  opacity: 1;
}
.page-about .colmock-cap {
  padding: 10px 14px;
  font-size: 12px;
  line-height: 1.5;
  color: var(--mist);
  background: var(--night-800);
  border-top: 1px solid var(--steel);
}

/* ---------- 时间轴 ---------- */
.page-about .tl {
  margin: 8px 0 0;
  padding: 0;
  list-style: none;
}
.page-about .tl-item {
  position: relative;
  display: grid;
  grid-template-columns: 92px minmax(0, 1fr);
  gap: 0 22px;
  padding-bottom: 26px;
}
.page-about .tl-item::after {
  content: "";
  position: absolute;
  left: 103px;
  top: 34px;
  bottom: 0;
  width: 1px;
  background: linear-gradient(180deg, var(--steel), rgba(42, 58, 99, 0.15));
}
.page-about .tl-item:last-child {
  padding-bottom: 0;
}
.page-about .tl-item:last-child::after {
  display: none;
}
.page-about .tl-seq {
  padding-top: 6px;
  padding-right: 12px;
  text-align: right;
  font-size: 14px;
  font-weight: 700;
  color: var(--gold);
  font-variant-numeric: tabular-nums;
}
.page-about .tl-card {
  padding: 16px 18px 18px;
}
.page-about .tl-phase {
  margin: 0 0 8px;
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--cyan);
  text-transform: uppercase;
}
.page-about .tl-text {
  margin: 0;
  font-size: 15px;
  line-height: 1.72;
  color: var(--mist);
  max-width: 64ch;
}

/* ---------- 团队分工 ---------- */
.page-about .crew-list {
  margin: 6px 0 0;
  padding: 0;
  list-style: none;
}
.page-about .crew-row {
  display: grid;
  grid-template-columns: 42px minmax(0, 1fr);
  gap: 6px 18px;
  padding: 22px 0;
  border-top: 1px solid var(--steel);
}
.page-about .crew-row:last-child {
  border-bottom: 1px solid var(--steel);
}
.page-about .crew-idx {
  grid-row: 1 / span 2;
  padding-top: 4px;
  font-size: 14px;
  font-weight: 700;
  color: var(--gold);
}
.page-about .crew-name {
  margin: 0;
  font-size: 17px;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--snow);
}
.page-about .crew-desc {
  margin: 6px 0 0;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.72;
  color: var(--mist);
}
.page-about .crew-tail {
  margin-top: 24px;
  padding-left: 16px;
  border-left: 2px solid var(--cyan);
}

/* ---------- 合作与互认 ---------- */
.page-about .partner-list {
  margin: 0;
  padding: 0;
  list-style: none;
}
.page-about .partner-item {
  display: grid;
  grid-template-columns: 92px minmax(0, 1fr);
  gap: 0 22px;
  align-items: start;
  padding: 22px 0;
  border-top: 1px solid var(--steel);
}
.page-about .partner-item:last-child {
  border-bottom: 1px solid var(--steel);
}
.page-about .partner-num {
  font-size: 32px;
  font-weight: 700;
  line-height: 1;
  color: var(--gold);
  font-variant-numeric: tabular-nums;
}
.page-about .partner-name {
  margin: 0;
  font-size: 17px;
  font-weight: 700;
  color: var(--snow);
}
.page-about .partner-desc {
  margin: 8px 0 0;
  max-width: 60ch;
  font-size: 15px;
  line-height: 1.72;
  color: var(--mist);
}
.page-about .slash-rule {
  margin: 26px 0 20px;
}

/* ---------- 站点边界 ---------- */
.page-about .boundary-list {
  display: grid;
  gap: 14px;
  margin: 4px 0 28px;
  padding: 0;
  list-style: none;
}
.page-about .boundary-list li {
  position: relative;
  padding-left: 26px;
  font-size: 16px;
  line-height: 1.7;
  color: var(--mist);
}
.page-about .boundary-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 12px;
  width: 13px;
  height: 2px;
  background: var(--signal);
}
.page-about .about-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 30px;
}

/* ---------- 响应式 ---------- */
@media (max-width: 900px) {
  .page-about .about-sec .sec-head {
    width: 100%;
  }
  .page-about .tl-item {
    grid-template-columns: 76px minmax(0, 1fr);
    gap: 0 14px;
  }
  .page-about .tl-item::after {
    left: 83px;
  }
  .page-about .partner-item {
    grid-template-columns: 70px minmax(0, 1fr);
    gap: 0 16px;
  }
  .page-about .partner-num {
    font-size: 26px;
  }
}

@media (max-width: 640px) {
  .page-about .hero-glyph {
    font-size: 54px;
    opacity: 0.45;
  }
  .page-about .hero-facts li {
    padding: 0 16px;
  }
  .page-about .hero-facts li:first-child {
    padding-left: 0;
  }
  .page-about .colmock-body {
    grid-template-columns: 1fr;
  }
  .page-about .colmock-col--3 {
    grid-column: auto;
  }
  .page-about .colmock-hint {
    max-height: 120px;
    margin-top: 8px;
    opacity: 1;
  }
  .page-about .tl-item {
    grid-template-columns: 58px minmax(0, 1fr);
    gap: 0 12px;
    padding-bottom: 20px;
  }
  .page-about .tl-item::after {
    left: 64px;
    top: 30px;
  }
  .page-about .tl-seq {
    font-size: 12px;
    padding-right: 8px;
  }
  .page-about .tl-card {
    padding: 14px 15px 16px;
  }
  .page-about .crew-row {
    grid-template-columns: 30px minmax(0, 1fr);
    gap: 6px 12px;
  }
  .page-about .partner-item {
    grid-template-columns: 1fr;
    gap: 8px;
  }
  .page-about .about-cta .btn {
    flex: 1 1 auto;
    justify-content: center;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .toc-link,
  .page-about .colmock-hint,
  .page-about .colmock-col {
    transition-duration: 0.01ms;
  }
}

.page-about {
  --sec-w: 1rem;
}