.page-about {
  --about-rail: 264px;
  display: block;
}

/* ---------- 面包屑 ---------- */
.page-about .crumb {
  margin: clamp(14px, 2.6vw, 24px) 0 0;
  font-size: 13px;
  color: var(--muted);
}

.page-about .crumb a {
  color: var(--cyan);
  text-decoration: none;
}

.page-about .crumb a:hover {
  text-decoration: underline;
}

.page-about .crumb-sep {
  margin: 0 8px;
  color: var(--line);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: clamp(26px, 4vw, 52px) 0 clamp(30px, 5vw, 60px);
  border-bottom: 1px solid var(--line);
  background:
    radial-gradient(900px 420px at 86% -10%, rgba(155, 108, 255, .20), transparent 68%),
    radial-gradient(720px 380px at 4% 22%, rgba(36, 224, 210, .13), transparent 70%);
}

.page-about .about-hero-grid {
  display: grid;
  gap: clamp(24px, 4vw, 44px);
}

.page-about .hero-kicker {
  margin: 0;
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--cyan);
  text-transform: uppercase;
}

.page-about .hero-copy h1 {
  margin: 14px 0 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(29px, 5vw, 54px);
  line-height: 1.1;
  letter-spacing: -.02em;
  color: var(--ink);
  max-width: 20ch;
}

.page-about .hero-lede {
  margin: 18px 0 0;
  max-width: 620px;
  font-size: 17px;
  line-height: 1.78;
  color: var(--ink);
}

.page-about .hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 24px;
}

.page-about .hero-figure {
  margin: 0;
  aspect-ratio: 14 / 9;
  overflow: hidden;
  position: relative;
}

.page-about .hero-figure img {
  width: 100%;
  height: 100%;
  display: block;
  object-fit: cover;
  filter: saturate(.82) contrast(1.06);
}

.page-about .hero-figure figcaption {
  position: absolute;
  left: 0;
  bottom: 0;
  padding: 10px 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--ink);
  background: rgba(7, 12, 20, .82);
  border-top: 1px solid var(--line);
  border-right: 1px solid var(--line);
}

/* ---------- 章节索引条 ---------- */
.page-about .page-index {
  padding-top: clamp(18px, 3vw, 30px);
}

.page-about .page-index-list {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 0 0 8px;
  list-style: none;
  overflow-x: auto;
  border-bottom: 1px solid var(--line);
  scrollbar-width: none;
}

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

.page-about .page-index-list a {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 8px 16px 9px 13px;
  border: 1px solid var(--line);
  background: rgba(14, 23, 48, .6);
  color: var(--muted);
  font-size: 14px;
  white-space: nowrap;
  text-decoration: none;
  clip-path: polygon(0 0, 100% 0, calc(100% - 9px) 100%, 0 100%);
  transition: color .2s ease, border-color .2s ease, background .2s ease;
}

.page-about .page-index-list a:hover,
.page-about .page-index-list a:focus-visible {
  color: var(--ink);
  border-color: var(--cyan);
  background: rgba(36, 224, 210, .1);
}

.page-about .idx-num {
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--cyan);
}

/* ---------- 通用章节 ---------- */
.page-about .about-section {
  padding: clamp(38px, 6.5vw, 84px) 0;
}

.page-about .about-section + .about-section {
  border-top: 1px solid var(--line-soft);
}

.page-about .about-section--tinted {
  background: linear-gradient(180deg, rgba(14, 23, 48, .88), rgba(7, 12, 20, .98));
}

.page-about .section-head {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding-bottom: 14px;
  margin-bottom: clamp(20px, 3vw, 32px);
  border-bottom: 1px solid var(--line);
}

.page-about .section-num {
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--cyan);
}

.page-about .section-head h2 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(22px, 3.2vw, 34px);
  line-height: 1.2;
  letter-spacing: -.01em;
  color: var(--ink);
}

.page-about .section-lede {
  margin: 0;
  max-width: 720px;
  font-size: 16.5px;
  line-height: 1.8;
  color: var(--muted);
}

/* ---------- 年份时间轴 ---------- */
.page-about .timeline-list {
  margin: clamp(22px, 3.4vw, 34px) 0 0;
  padding: 0;
  list-style: none;
  display: grid;
}

.page-about .tl-node {
  position: relative;
  padding: 0 0 clamp(22px, 3vw, 30px) 26px;
  border-left: 1px solid var(--line);
}

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

.page-about .tl-node::before {
  content: "";
  position: absolute;
  left: -5px;
  top: 6px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--pulse);
  box-shadow: 0 0 0 3px rgba(155, 108, 255, .18);
  transition: box-shadow .2s ease, background .2s ease;
}

.page-about .tl-node:last-child::before {
  background: var(--cyan);
  box-shadow: 0 0 0 3px rgba(36, 224, 210, .2);
}

.page-about .tl-node:hover::before {
  box-shadow: 0 0 0 6px rgba(36, 224, 210, .2);
}

.page-about .tl-year {
  display: block;
  font-size: 13px;
  letter-spacing: .1em;
  color: var(--cyan);
}

.page-about .tl-title {
  margin: 6px 0 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 18px;
  line-height: 1.4;
  color: var(--ink);
}

.page-about .tl-note {
  max-height: 120px;
  margin: 8px 0 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--muted);
  transition: color .2s ease;
}

.page-about .tl-node:hover .tl-note {
  color: var(--ink);
}

/* ---------- 团队 ---------- */
.page-about .team-layout {
  align-items: start;
}

.page-about .rail-note {
  margin: 0;
  padding: 16px 18px;
  border-left: 3px solid var(--pulse);
  background: rgba(36, 26, 70, .55);
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--ink);
}

.page-about .duty-scroll {
  overflow-x: auto;
  border: 1px solid var(--line);
  background: rgba(14, 23, 48, .72);
}

.page-about .duty-table {
  width: 100%;
  min-width: 660px;
  border-collapse: collapse;
  font-size: 14.5px;
}

.page-about .duty-table th,
.page-about .duty-table td {
  padding: 14px 16px;
  text-align: left;
  vertical-align: top;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .duty-table thead th {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: .14em;
  color: var(--muted);
  background: rgba(36, 224, 210, .06);
  white-space: nowrap;
}

.page-about .duty-table tbody th {
  color: var(--ink);
  font-weight: 600;
  white-space: nowrap;
}

.page-about .duty-table tbody td {
  color: var(--muted);
  line-height: 1.7;
}

.page-about .duty-table tbody td:last-child {
  color: var(--cyan);
  font-size: 13px;
  line-height: 1.6;
}

.page-about .duty-table tbody tr {
  transition: background .2s ease, box-shadow .2s ease;
}

.page-about .duty-table tbody tr:hover {
  background: rgba(36, 224, 210, .08);
  box-shadow: inset 3px 0 0 var(--cyan);
}

/* ---------- 覆盖规模 ---------- */
.page-about .coverage-grid {
  display: grid;
  gap: clamp(20px, 3vw, 36px);
}

.page-about .coverage-figure {
  margin: 0;
  aspect-ratio: 4 / 3;
  overflow: hidden;
  position: relative;
}

.page-about .coverage-figure img {
  width: 100%;
  height: 100%;
  display: block;
  object-fit: cover;
  filter: saturate(.8) brightness(.92);
}

.page-about .coverage-figure figcaption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.7;
  letter-spacing: .05em;
  color: var(--muted);
}

.page-about .stat-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 20px 0;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .stat-cell {
  padding: 16px 18px 18px;
  background: rgba(14, 23, 48, .92);
}

.page-about .stat-cell:nth-child(2),
.page-about .stat-cell:nth-child(3) {
  background: rgba(36, 26, 70, .6);
}

.page-about .stat-num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(28px, 4.4vw, 42px);
  font-weight: 700;
  line-height: 1.05;
  letter-spacing: -.02em;
  color: var(--cyan);
}

.page-about .stat-cell:nth-child(2) .stat-num,
.page-about .stat-cell:nth-child(4) .stat-num {
  color: var(--pulse);
}

.page-about .stat-unit {
  margin-left: 4px;
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 400;
  color: var(--muted);
  letter-spacing: 0;
}

.page-about .stat-label {
  display: block;
  margin-top: 8px;
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--muted);
}

.page-about .coverage-note {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--ink);
}

/* ---------- 内容分类折叠组 ---------- */
.page-about .entry-list {
  display: grid;
  gap: 10px;
}

.page-about .entry {
  border: 1px solid var(--line);
  background: rgba(14, 23, 48, .68);
  transition: border-color .2s ease, background .2s ease;
}

.page-about .entry[open] {
  border-color: rgba(36, 224, 210, .5);
  background: rgba(14, 23, 48, .96);
  box-shadow: inset 3px 0 0 var(--cyan);
}

.page-about .entry summary {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 15px 18px;
  cursor: pointer;
  list-style: none;
}

.page-about .entry summary::-webkit-details-marker {
  display: none;
}

.page-about .entry summary:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: -2px;
}

.page-about .entry-num {
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--cyan);
}

.page-about .entry-title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 19px;
  color: var(--ink);
}

.page-about .entry-hint {
  margin-left: auto;
  font-size: 13px;
  color: var(--muted);
  text-align: right;
}

.page-about .entry summary::after {
  content: "+";
  margin-left: 12px;
  font-family: var(--font-mono);
  font-size: 17px;
  color: var(--pulse);
}

.page-about .entry[open] summary::after {
  content: "–";
  color: var(--cyan);
}

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

.page-about .entry-body p {
  margin: 14px 0 0;
  max-width: 70ch;
  font-size: 15.5px;
  line-height: 1.82;
  color: var(--ink);
}

.page-about .entry[open] .entry-body {
  animation: about-fade .26s ease both;
}

@keyframes about-fade {
  from { opacity: 0; transform: translateY(-4px); }
  to { opacity: 1; transform: none; }
}

/* ---------- 合作生态 ---------- */
.page-about .partner-layout {
  display: grid;
  gap: clamp(20px, 3vw, 36px);
}

.page-about .partner-list {
  display: grid;
  gap: 10px;
}

.page-about .partner-card {
  position: relative;
  padding: 20px 20px 22px;
  border: 1px solid var(--line);
  background: linear-gradient(135deg, rgba(58, 16, 32, .55), rgba(14, 23, 48, .9) 62%);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 15px), calc(100% - 15px) 100%, 0 100%);
  transition: border-color .2s ease, transform .2s ease;
}

.page-about .partner-card:hover {
  border-color: rgba(155, 108, 255, .55);
  transform: translateY(-2px);
}

.page-about .partner-count {
  display: block;
  font-size: 34px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--cyan);
}

.page-about .partner-name {
  margin: 8px 0 10px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 18px;
  color: var(--ink);
}

.page-about .partner-desc {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--muted);
}

.page-about .partner-figure {
  margin: 0;
  aspect-ratio: 11 / 8;
  overflow: hidden;
  position: relative;
}

.page-about .partner-figure img {
  width: 100%;
  height: 100%;
  display: block;
  object-fit: cover;
  filter: saturate(.75) contrast(1.08);
}

.page-about .partner-figure figcaption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.7;
  letter-spacing: .05em;
  color: var(--muted);
}

/* ---------- 数据校准（纸质叠层） ---------- */
.page-about .fix-panel {
  position: relative;
  max-width: 800px;
  padding: clamp(20px, 3vw, 34px);
  background: var(--paper);
  color: var(--ink-dark);
  border: 1px solid var(--ink-dark);
  box-shadow: 7px 7px 0 rgba(36, 224, 210, .32), 14px 14px 0 rgba(155, 108, 255, .22);
}

.page-about .fix-panel h3 {
  margin: 0 0 12px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(19px, 2.6vw, 25px);
  line-height: 1.3;
  letter-spacing: -.01em;
  color: var(--ink-dark);
}

.page-about .fix-panel p {
  margin: 0 0 12px;
  font-size: 15.5px;
  line-height: 1.82;
  color: #1b2432;
}

.page-about .fix-list {
  margin: 16px 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 9px;
}

.page-about .fix-list li {
  display: flex;
  gap: 10px;
  font-size: 14.5px;
  line-height: 1.72;
  color: #1b2432;
}

.page-about .fix-list li::before {
  content: "—";
  flex: none;
  font-family: var(--font-mono);
  color: #0b7a74;
}

.page-about .fix-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 20px;
}

.page-about .fix-panel .btn--ghost {
  color: var(--ink-dark);
  border-color: rgba(11, 18, 32, .48);
}

.page-about .fix-panel .btn--ghost:hover,
.page-about .fix-panel .btn--ghost:focus-visible {
  color: var(--ink-dark);
  border-color: var(--ink-dark);
  background: rgba(11, 18, 32, .07);
}

/* ---------- 长期价值 ---------- */
.page-about .reason-list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .reason {
  padding: clamp(20px, 3vw, 28px);
  background: rgba(7, 12, 20, .96);
  transition: background .2s ease;
}

.page-about .reason:hover {
  background: rgba(14, 23, 48, .96);
}

.page-about .reason-num {
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--cyan);
}

.page-about .reason h3 {
  margin: 10px 0 10px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 20px;
  color: var(--ink);
}

.page-about .reason p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .about-cta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 16px;
  margin-top: clamp(22px, 3.4vw, 34px);
  padding-top: clamp(20px, 3vw, 28px);
  border-top: 1px solid var(--line);
}

.page-about .about-cta .prose {
  margin: 0;
  flex: 1 1 320px;
  font-size: 15.5px;
  color: var(--ink);
}

/* ---------- 响应式 ---------- */
@media (min-width: 760px) {
  .page-about .stat-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

@media (min-width: 900px) {
  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, .92fr);
    align-items: end;
  }

  .page-about .timeline-list {
    grid-template-columns: repeat(5, minmax(0, 1fr));
    border-top: 1px solid var(--line);
  }

  .page-about .tl-node {
    padding: 28px 22px 0 0;
    border-left: 0;
  }

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

  .page-about .tl-node::before {
    left: 0;
    top: -5px;
  }

  .page-about .coverage-grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.18fr);
    align-items: start;
  }

  .page-about .partner-layout {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr);
    align-items: start;
  }
}

@media (min-width: 1100px) {
  .page-about .about-hero {
    padding-bottom: clamp(40px, 5vw, 72px);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .entry[open] .entry-body {
    animation: none;
  }

  .page-about .partner-card,
  .page-about .page-index-list a,
  .page-about .duty-table tbody tr,
  .page-about .tl-node::before {
    transition: none;
  }

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