.page-about {
  --stream-pad: clamp(20px, 3vw, 44px);
  padding-bottom: clamp(56px, 9vw, 120px);
}

.page-about .about-top {
  padding-top: clamp(20px, 4vw, 40px);
}

/* 首屏 */
.page-about .about-hero {
  display: grid;
  gap: clamp(24px, 4vw, 48px);
  padding-top: clamp(28px, 5vw, 56px);
  padding-bottom: clamp(32px, 5vw, 56px);
  border-bottom: 1px solid var(--line);
}

.page-about .about-hero-copy h1 {
  margin: 12px 0 0;
  font-family: var(--font-title);
  font-size: var(--fs-h1);
  font-weight: 900;
  letter-spacing: -0.02em;
  line-height: 1.12;
  color: var(--text);
  max-width: 16ch;
}

.page-about .about-lead {
  margin: 20px 0 0;
  max-width: 64ch;
  font-size: clamp(1rem, 1.3vw, 1.1rem);
  line-height: 1.8;
  color: var(--muted);
}

.page-about .about-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.page-about .about-hero-media {
  aspect-ratio: 16 / 10;
}

.page-about .about-hero-media img,
.page-about .chapter-media img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* 首屏速览数据 */
.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  border-bottom: 1px solid var(--line);
}

.page-about .stat {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 20px 4px 24px 16px;
  border-left: 1px solid var(--line);
}

.page-about .stat:first-child {
  border-left: 0;
  padding-left: 0;
}

.page-about .stat-num {
  font-family: var(--font-mono);
  font-size: clamp(1.5rem, 3vw, 2.2rem);
  font-weight: 700;
  letter-spacing: 0.03em;
  line-height: 1.1;
  font-variant-numeric: tabular-nums;
}

.page-about .stat--blue .stat-num { color: var(--blue); }
.page-about .stat--ice .stat-num { color: var(--ice); }
.page-about .stat--orange .stat-num { color: var(--orange); }
.page-about .stat--green .stat-num { color: var(--green); }

.page-about .stat-label {
  font-size: var(--fs-small);
  color: var(--muted);
  letter-spacing: 0.04em;
}

/* 主体：左侧坐标 + 右侧连续叙述 */
.page-about .about-body {
  display: grid;
  gap: clamp(20px, 3vw, 40px);
  padding-top: clamp(36px, 6vw, 72px);
}

.page-about .about-rail {
  position: relative;
  border-bottom: 1px solid var(--line);
  padding-bottom: 16px;
}

.page-about .rail-title {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--blue);
}

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

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

.page-about .rail-list li { flex: 0 0 auto; }

.page-about .rail-list a {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 8px 12px;
  font-size: 14px;
  color: var(--muted);
  text-decoration: none;
  white-space: nowrap;
  border-bottom: 2px solid transparent;
  transition: color .2s var(--ease), border-color .2s var(--ease), background .2s var(--ease);
}

.page-about .rail-list a:hover {
  color: var(--text);
  border-bottom-color: var(--orange);
  background: rgba(45, 107, 255, 0.10);
}

.page-about .rail-list a:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 3px;
  color: var(--text);
  border-bottom-color: var(--orange);
}

.page-about .rail-num {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--blue);
}

.page-about .rail-note {
  display: none;
  margin: 16px 0 0;
  font-size: var(--fs-small);
  line-height: 1.6;
  color: var(--muted);
  max-width: 22ch;
}

/* 叙述流与时间轴主线 */
.page-about .about-stream {
  position: relative;
  padding-left: var(--stream-pad);
  border-left: 1px solid var(--line);
}

.page-about .chapter {
  position: relative;
  padding-bottom: clamp(36px, 5vw, 64px);
  margin-bottom: clamp(36px, 5vw, 64px);
  border-bottom: 1px solid var(--line);
}

.page-about .chapter:last-child {
  border-bottom: 0;
  margin-bottom: 0;
  padding-bottom: 0;
}

.page-about .chapter::before {
  content: "";
  position: absolute;
  left: calc(-1 * var(--stream-pad) - 4px);
  top: 8px;
  width: 8px;
  height: 8px;
  background: var(--ink);
  border: 1px solid var(--blue);
  transform: rotate(45deg);
  transition: background .2s var(--ease), border-color .2s var(--ease), box-shadow .2s var(--ease);
}

.page-about .chapter:hover::before {
  background: var(--orange);
  border-color: var(--orange);
  box-shadow: 0 0 0 4px rgba(255, 106, 42, 0.14);
}

.page-about .chapter-num {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--orange);
}

.page-about .chapter h2 {
  margin: 0 0 18px;
  font-family: var(--font-title);
  font-size: var(--fs-h2);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.2;
  color: var(--text);
}

.page-about .chapter p {
  margin: 0 0 16px;
  max-width: 68ch;
  line-height: 1.85;
  color: var(--muted);
}

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

.page-about .chapter-foot {
  margin-top: 20px;
  padding-top: 14px;
  border-top: 1px dashed var(--line);
  font-family: var(--font-mono);
  font-size: var(--fs-small);
  letter-spacing: 0.04em;
  color: var(--ice);
}

/* 覆盖图 */
.page-about .coverage-figure {
  margin: 28px 0 0;
}

.page-about .coverage-map {
  display: block;
  width: 100%;
  height: auto;
  background: linear-gradient(180deg, rgba(16, 26, 46, 0.92), rgba(5, 7, 13, 0.92));
  border: 1px solid var(--line);
}

.page-about .cov-grid line {
  stroke: var(--line);
  stroke-width: 1;
}

.page-about .cov-dot--orange { fill: var(--orange); }
.page-about .cov-dot--blue { fill: var(--blue); }
.page-about .cov-dot--green { fill: var(--green); }
.page-about .cov-dot--amber { fill: var(--amber); }

.page-about .cov-label {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.06em;
  fill: var(--muted);
}

.page-about .cov-label--orange { fill: var(--orange); }
.page-about .cov-label--blue { fill: var(--ice); }
.page-about .cov-label--green { fill: var(--green); }
.page-about .cov-label--amber { fill: var(--amber); }

.page-about .media-caption {
  margin-top: 10px;
  font-size: var(--fs-small);
  line-height: 1.6;
  color: var(--muted);
}

/* 成长阶段 */
.page-about .phase-list {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
}

.page-about .phase {
  position: relative;
  padding: 0 0 30px 26px;
  border-left: 1px solid var(--line);
  transition: border-color .2s var(--ease);
}

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

.page-about .phase:hover { border-left-color: var(--blue); }

.page-about .phase-node {
  position: absolute;
  left: -4.5px;
  top: 7px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--ink);
  border: 1px solid var(--blue);
  transition: background .2s var(--ease), border-color .2s var(--ease), box-shadow .2s var(--ease);
}

.page-about .phase:hover .phase-node {
  background: var(--orange);
  border-color: var(--orange);
  box-shadow: 0 0 0 4px rgba(255, 106, 42, 0.16);
}

.page-about .phase-tag {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--blue);
}

.page-about .phase h3 {
  margin: 0 0 10px;
  font-family: var(--font-title);
  font-size: var(--fs-h3);
  font-weight: 700;
  color: var(--text);
  line-height: 1.3;
}

.page-about .phase p {
  margin: 0 0 10px;
  max-width: 66ch;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .phase-foot {
  font-family: var(--font-mono);
  font-size: var(--fs-small);
  letter-spacing: 0.03em;
  color: var(--green);
}

.page-about .chapter-media {
  margin: 28px 0 0;
  aspect-ratio: 3 / 2;
}

/* 数据流程 */
.page-about .flow-list {
  display: grid;
  gap: 1px;
  margin: 24px 0 0;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .flow-item {
  background: var(--panel);
  padding: 22px 20px;
  transition: background .2s var(--ease);
}

.page-about .flow-item:hover { background: #14213A; }

.page-about .flow-num {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--orange);
  margin-bottom: 8px;
}

.page-about .flow-item h3 {
  margin: 0 0 8px;
  font-family: var(--font-title);
  font-size: var(--fs-h3);
  font-weight: 700;
  color: var(--text);
}

.page-about .flow-item p {
  margin: 0;
  max-width: 62ch;
  line-height: 1.8;
  color: var(--muted);
}

/* 团队 */
.page-about .team-grid {
  list-style: none;
  margin: 24px 0 24px;
  padding: 0;
  display: grid;
  gap: 16px;
}

.page-about .team-card {
  padding: 22px 20px;
  background: var(--panel);
  border-top: 2px solid var(--blue);
  transition: transform .2s var(--ease), border-color .2s var(--ease);
}

.page-about .team-card:nth-child(2) { border-top-color: var(--orange); }
.page-about .team-card:nth-child(3) { border-top-color: var(--green); }

.page-about .team-card:hover {
  transform: translateY(-3px);
  border-top-color: var(--ice);
}

.page-about .team-num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(2rem, 4vw, 2.8rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0.02em;
  font-variant-numeric: tabular-nums;
  color: var(--orange);
}

.page-about .team-role {
  display: block;
  margin-top: 8px;
  font-weight: 700;
  color: var(--text);
  letter-spacing: 0.02em;
}

.page-about .team-card p {
  margin: 10px 0 0;
  line-height: 1.8;
  color: var(--muted);
}

/* 合作生态 */
.page-about .partners-split {
  display: grid;
  gap: clamp(24px, 4vw, 44px);
  margin-top: 20px;
}

.page-about .partners-copy p {
  margin: 0 0 16px;
  line-height: 1.85;
  color: var(--muted);
  max-width: 64ch;
}

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

.page-about .partners-figures {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  align-content: start;
}

.page-about .partners-figures li {
  background: var(--ink-2);
  padding: 16px 18px;
}

.page-about .pf-num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(1.6rem, 3vw, 2.2rem);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: 0.02em;
  font-variant-numeric: tabular-nums;
}

.page-about .pf-num--orange { color: var(--orange); }
.page-about .pf-num--blue { color: var(--ice); }
.page-about .pf-num--green { color: var(--green); }

.page-about .pf-label {
  display: block;
  margin-top: 6px;
  font-size: var(--fs-small);
  line-height: 1.6;
  color: var(--muted);
}

/* 原则 */
.page-about .principle-list {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: grid;
  gap: 16px;
}

.page-about .principle {
  display: grid;
  gap: 6px;
  padding: 18px 0 18px 18px;
  border-left: 2px solid var(--line);
  transition: border-color .2s var(--ease), padding-left .2s var(--ease);
}

.page-about .principle:hover {
  border-left-color: var(--orange);
  padding-left: 22px;
}

.page-about .principle-key {
  font-family: var(--font-title);
  font-size: var(--fs-h3);
  font-weight: 800;
  letter-spacing: 0.02em;
  color: var(--text);
}

.page-about .principle p {
  margin: 0;
  max-width: 64ch;
  line-height: 1.85;
  color: var(--muted);
}

/* 收束行动区 */
.page-about .about-cta {
  margin-top: clamp(28px, 4vw, 44px);
  padding: clamp(22px, 3vw, 32px);
  background:
    linear-gradient(120deg, rgba(45, 107, 255, 0.16), rgba(255, 106, 42, 0.10) 60%, rgba(92, 255, 157, 0.10));
  border: 1px solid var(--line);
}

.page-about .about-cta-title {
  margin: 0 0 18px;
  font-family: var(--font-title);
  font-size: var(--fs-h3);
  font-weight: 800;
  color: var(--text);
}

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

/* 中等屏幕 */
@media (min-width: 640px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

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

/* 桌面端 */
@media (min-width: 900px) {
  .page-about .about-hero {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: end;
  }

  .page-about .about-hero-media {
    aspect-ratio: 4 / 3;
  }

  .page-about .partners-split {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: start;
  }
}

@media (min-width: 960px) {
  .page-about .about-body {
    grid-template-columns: minmax(180px, 220px) minmax(0, 1fr);
    gap: clamp(32px, 5vw, 72px);
    align-items: start;
  }

  .page-about .about-rail {
    position: sticky;
    top: 96px;
    border-bottom: 0;
    padding-bottom: 0;
  }

  .page-about .rail-list {
    flex-direction: column;
    gap: 2px;
    overflow: visible;
  }

  .page-about .rail-list li { flex: none; }

  .page-about .rail-list a {
    border-bottom: 0;
    border-left: 2px solid transparent;
    padding: 9px 12px;
  }

  .page-about .rail-list a:hover {
    border-left-color: var(--orange);
    border-bottom-color: transparent;
  }

  .page-about .rail-list a:focus-visible {
    border-left-color: var(--orange);
  }

  .page-about .rail-note { display: block; }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .chapter::before,
  .page-about .phase-node,
  .page-about .team-card,
  .page-about .principle,
  .page-about .flow-item,
  .page-about .rail-list a {
    transition: none;
  }

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