.page-about {
  --about-rule: 1px solid var(--line);
  --about-rule-soft: 1px solid var(--grid);
  --about-pad: 20px;
}

/* ---------- 首屏框景 ---------- */
.page-about .about-hero {
  padding-bottom: 8px;
}

.page-about .about-hero-frame {
  position: relative;
  border: 2px solid var(--line);
  background:
    linear-gradient(180deg, rgba(56, 242, 206, .07), transparent 46%),
    var(--ink-2);
  box-shadow: var(--shadow-hard);
  padding: 30px var(--about-pad) 32px;
}

.page-about .about-hero-frame::before,
.page-about .about-hero-frame::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  height: 9px;
  background: repeating-linear-gradient(90deg, var(--line) 0 1px, transparent 1px 18px);
  opacity: .85;
  pointer-events: none;
}

.page-about .about-hero-frame::before { top: 0; }
.page-about .about-hero-frame::after { bottom: 0; }

.page-about .about-hero-frame .breadcrumb {
  margin-bottom: 22px;
}

.page-about .about-hero-frame .h-display {
  max-width: 20ch;
  margin: 14px 0 0;
}

.page-about .about-hero-frame .lead {
  max-width: 60ch;
  margin: 18px 0 0;
  color: var(--body-copy);
}

.page-about .about-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

.page-about .about-keyline {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin: 32px 0 0;
  padding: 0;
  border-top: var(--about-rule);
  border-left: var(--about-rule);
}

.page-about .keyline-item {
  padding: 14px 16px;
  border-right: var(--about-rule);
  border-bottom: var(--about-rule);
}

.page-about .keyline-item dt {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--mist);
  margin-bottom: 7px;
}

.page-about .keyline-item dd {
  margin: 0;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(20px, 5vw, 26px);
  font-weight: 700;
  letter-spacing: .02em;
  color: var(--cyan);
}

/* ---------- 主体网格 ---------- */
.page-about .about-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 34px;
  align-items: start;
}

/* ---------- 章节索引 ---------- */
.page-about .about-toc {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 18px;
  padding: 0 0 18px;
  border-bottom: var(--about-rule);
}

.page-about .toc-head {
  width: 100%;
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--mist);
}

.page-about .about-toc .toc-link {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 6px 2px;
  border-bottom: 2px solid transparent;
  font-size: 14px;
  line-height: 1.3;
  color: var(--mist);
  text-decoration: none;
  transition: color .2s var(--ease), border-color .2s var(--ease);
}

.page-about .about-toc .toc-link:hover,
.page-about .about-toc .toc-link:focus-visible {
  color: var(--chalk);
  border-bottom-color: var(--line);
}

.page-about .about-toc .toc-link[aria-current="true"] {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

.page-about .toc-idx {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--pitch);
}

.page-about .about-toc .toc-link:hover .toc-idx,
.page-about .about-toc .toc-link[aria-current="true"] .toc-idx {
  color: var(--cyan);
}

/* ---------- 区块节奏 ---------- */
.page-about .about-flow > .about-block {
  padding-top: 40px;
  margin-top: 40px;
  border-top: var(--about-rule);
}

.page-about .about-flow > .about-block:first-child {
  padding-top: 0;
  margin-top: 0;
  border-top: 0;
}

.page-about .about-block .section-head {
  margin-bottom: 22px;
}

.page-about .about-block .h2 {
  margin-top: 10px;
  max-width: 24ch;
}

.page-about .about-block .prose {
  max-width: 68ch;
}

.page-about .about-block .prose p {
  margin: 0 0 1.1em;
  color: var(--body-copy);
}

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

.page-about .inline-link {
  color: var(--cyan);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ---------- 图文分栏 ---------- */
.page-about .about-split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 26px;
  margin-top: 24px;
}

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

.page-about .img-frame__inner {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  background: var(--grid);
}

.page-about .about-figure .img-cap {
  margin-top: 10px;
  font-size: 12px;
  line-height: 1.6;
  color: var(--mist);
}

.page-about .about-figure--full {
  margin-top: 34px;
}

/* ---------- 时间轴 ---------- */
.page-about .timeline {
  list-style: none;
  margin: 40px 0 0;
  padding: 0;
}

.page-about .timeline-node {
  position: relative;
  padding: 0 0 30px 44px;
}

.page-about .timeline-node::before {
  content: "";
  position: absolute;
  left: 9px;
  top: 24px;
  bottom: 0;
  width: 2px;
  background: var(--grid);
}

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

.page-about .timeline-node:last-child::before {
  display: none;
}

.page-about .timeline-node::after {
  content: "";
  position: absolute;
  left: 0;
  top: 2px;
  width: 20px;
  height: 20px;
  background: var(--ink);
  border: 2px solid var(--cyan);
  transition: background .2s var(--ease);
}

.page-about .timeline-node:hover::after {
  background: var(--cyan);
}

.page-about .node-season {
  display: inline-block;
  padding: 3px 9px;
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--cyan);
  background: var(--ink-2);
  border: 1px solid var(--line);
}

.page-about .node-title {
  margin: 12px 0 6px;
  font-size: 18px;
  font-weight: 700;
  line-height: 1.3;
  color: var(--chalk);
}

.page-about .node-text {
  margin: 0;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.75;
  color: var(--body-copy);
}

.page-about .node-tags {
  margin: 10px 0 0;
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--mist);
  opacity: .55;
  transition: opacity .2s var(--ease), color .2s var(--ease);
}

.page-about .timeline-node:hover .node-tags,
.page-about .timeline-node:focus-within .node-tags {
  opacity: 1;
  color: var(--cyan-soft);
}

/* ---------- 组织图 ---------- */
.page-about .org-chart {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 18px;
  margin-top: 18px;
  padding-top: 42px;
}

.page-about .org-chart::before {
  content: "";
  position: absolute;
  top: 20px;
  left: 12%;
  right: 12%;
  height: 2px;
  background: var(--line);
}

.page-about .org-col {
  position: relative;
  padding: 20px 18px 22px;
  background: var(--ink-2);
  border: 2px solid var(--line);
  box-shadow: var(--shadow-soft);
  transition: transform .2s var(--ease), box-shadow .2s var(--ease);
}

.page-about .org-col::before {
  content: "";
  position: absolute;
  top: -22px;
  left: 50%;
  width: 2px;
  height: 22px;
  background: var(--line);
}

.page-about .org-col:hover {
  transform: translate(3px, 3px);
  box-shadow: 2px 2px 0 rgba(0, 0, 0, .45);
}

.page-about .org-num {
  margin: 0 0 6px;
  font-size: 40px;
  font-weight: 700;
  line-height: 1;
  font-variant-numeric: tabular-nums;
  color: var(--cyan);
}

.page-about .org-unit {
  margin-left: 5px;
  font-family: var(--font-body);
  font-size: 13px;
  font-weight: 500;
  color: var(--mist);
}

.page-about .org-role {
  margin: 0 0 10px;
  font-size: 16px;
  font-weight: 700;
  color: var(--chalk);
}

.page-about .org-duty {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--body-copy);
}

/* ---------- 数据来源面板 ---------- */
.page-about .source-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 18px;
  margin-top: 26px;
}

.page-about .source-panel {
  padding: 22px 20px;
  background: var(--ink-2);
  border: 2px solid var(--line);
  box-shadow: var(--shadow-soft);
}

.page-about .source-panel h3 {
  margin: 0 0 14px;
  padding-bottom: 10px;
  font-size: 16px;
  font-weight: 700;
  color: var(--chalk);
  border-bottom: var(--about-rule-soft);
}

.page-about .source-list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .source-list li {
  position: relative;
  padding: 9px 0 9px 18px;
  font-size: 15px;
  line-height: 1.7;
  color: var(--body-copy);
  border-bottom: 1px dashed var(--grid);
}

.page-about .source-list li:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}

.page-about .source-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 18px;
  width: 9px;
  height: 2px;
  background: var(--cyan);
}

.page-about .source-note {
  margin-top: 24px;
  padding-left: 16px;
  border-left: 3px solid var(--pitch);
}

/* ---------- 四步流程 ---------- */
.page-about .flow {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin: 34px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .flow-step {
  position: relative;
  padding: 18px 16px 20px;
  background: var(--ink-2);
  border: 2px solid var(--line);
  box-shadow: var(--shadow-soft);
}

.page-about .flow-step--key {
  border-color: var(--signal);
}

.page-about .flow-idx {
  display: block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--cyan);
}

.page-about .flow-step--key .flow-idx {
  color: var(--signal);
}

.page-about .flow-title {
  margin: 0 0 6px;
  font-size: 16px;
  font-weight: 700;
  color: var(--chalk);
}

.page-about .flow-text {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--body-copy);
}

/* ---------- 专栏方向 ---------- */
.page-about .editorial-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin-top: 26px;
}

.page-about .direction {
  padding: 18px 18px 18px 22px;
  background: var(--ink-2);
  border: 2px solid var(--grid);
  border-left: 4px solid var(--pitch);
  transition: border-color .2s var(--ease), border-left-color .2s var(--ease);
}

.page-about .direction:hover {
  border-color: var(--line);
  border-left-color: var(--cyan);
}

.page-about .direction-name {
  margin: 0 0 8px;
  font-size: 16px;
  font-weight: 700;
  color: var(--chalk);
}

.page-about .direction-text {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--body-copy);
}

/* ---------- 事实清单 ---------- */
.page-about .fact-list {
  margin: 26px 0 0;
  padding: 0;
  border-top: var(--about-rule);
}

.page-about .fact-row {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 24px;
  align-items: baseline;
  justify-content: space-between;
  padding: 15px 0;
  border-bottom: var(--about-rule);
}

.page-about .fact-key {
  flex: 0 0 auto;
  min-width: 92px;
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--mist);
}

.page-about .fact-value {
  flex: 1 1 260px;
  margin: 0;
  font-size: 15px;
  line-height: 1.7;
  color: var(--chalk);
}

.page-about .compliance-note {
  margin-top: 24px;
  font-size: 14px;
  color: var(--mist);
}

/* ---------- 合作 ---------- */
.page-about .partner-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 18px;
  margin-top: 26px;
}

.page-about .partner-card {
  padding: 22px 20px;
  background:
    linear-gradient(135deg, rgba(23, 81, 63, .5), transparent 62%),
    var(--ink-2);
  border: 2px solid var(--line);
  box-shadow: var(--shadow-soft);
}

.page-about .partner-num {
  margin: 0 0 6px;
  font-size: 36px;
  font-weight: 700;
  line-height: 1;
  font-variant-numeric: tabular-nums;
  color: var(--cyan);
}

.page-about .partner-label {
  margin: 0 0 10px;
  font-size: 16px;
  font-weight: 700;
  color: var(--chalk);
}

.page-about .partner-text {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--body-copy);
}

.page-about .about-cta {
  display: grid;
  gap: 18px;
  margin-top: 34px;
  padding: 24px 20px;
  background: var(--ink-2);
  border: 2px solid var(--signal);
  box-shadow: var(--shadow-hard);
}

.page-about .cta-text {
  margin: 0;
  max-width: 58ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--body-copy);
}

.page-about .cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* ---------- 平板 ---------- */
@media (min-width: 700px) {
  .page-about {
    --about-pad: 34px;
  }

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

  .page-about .org-chart {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 22px;
  }

  .page-about .source-grid,
  .page-about .editorial-grid,
  .page-about .partner-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .flow {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

/* ---------- 桌面：左侧粘性索引 + 正文两栏 ---------- */
@media (min-width: 1000px) {
  .page-about .about-grid {
    grid-template-columns: 196px minmax(0, 1fr);
    gap: 60px;
  }

  .page-about .about-toc {
    position: sticky;
    top: 118px;
    display: block;
    padding: 0 0 0 0;
    border-bottom: 0;
  }

  .page-about .toc-head {
    margin-bottom: 14px;
  }

  .page-about .about-toc .toc-link {
    display: flex;
    width: 100%;
    padding: 10px 0 10px 14px;
    border-bottom: 0;
    border-left: 2px solid var(--grid);
  }

  .page-about .about-toc .toc-link:hover,
  .page-about .about-toc .toc-link:focus-visible {
    border-bottom-color: transparent;
    border-left-color: var(--line);
  }

  .page-about .about-toc .toc-link[aria-current="true"] {
    border-bottom-color: transparent;
    border-left-color: var(--cyan);
  }

  .page-about .about-split {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr);
    gap: 36px;
    align-items: start;
  }

  .page-about .about-split--media-first {
    grid-template-columns: minmax(0, .9fr) minmax(0, 1.1fr);
  }

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

  .page-about .flow-step:not(:last-child)::after {
    content: "";
    position: absolute;
    right: -15px;
    top: 50%;
    width: 16px;
    height: 2px;
    background: var(--line);
    z-index: 1;
  }

  .page-about .about-cta {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    padding: 26px 28px;
  }
}

@media (min-width: 1320px) {
  .page-about .about-hero-frame {
    margin-right: -28px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-toc .toc-link,
  .page-about .timeline-node::after,
  .page-about .node-tags,
  .page-about .org-col,
  .page-about .direction {
    transition: none;
  }

  .page-about .org-col:hover {
    transform: none;
    box-shadow: var(--shadow-soft);
  }
}