.page-about {
  --about-rail: 208px;
  --about-metric: 152px;
}

/* ===== 首屏 ===== */
.page-about .about-hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 26px;
  align-items: start;
  margin-top: 18px;
}

.page-about h1 {
  font-family: var(--font-display);
  font-size: clamp(32px, 5.4vw, 54px);
  line-height: 1.06;
  letter-spacing: -0.02em;
  font-weight: 800;
  color: var(--ink);
  margin: 10px 0 16px;
}

.page-about .about-hero .lead {
  color: var(--ink);
  font-size: 16px;
  line-height: 1.8;
  max-width: 56ch;
  margin: 0 0 22px;
}

.page-about .about-hero-facts {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  border-top: 1px solid var(--line);
  padding-top: 14px;
}

.page-about .fact {
  padding: 0 10px;
  border-left: 1px solid var(--line);
  min-width: 0;
}

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

.page-about .fact-num {
  display: block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(20px, 3vw, 26px);
  line-height: 1.1;
  color: var(--orange);
}

.page-about .fact-label {
  display: block;
  margin-top: 5px;
  font-size: 12px;
  line-height: 1.5;
  color: var(--muted);
}

.page-about .about-hero-media {
  margin: 0;
}

.page-about .about-hero-media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 10;
  object-fit: cover;
  border: 1px solid var(--line);
}

/* ===== 阶段档案 ===== */
.page-about .about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 30px;
  margin-top: 52px;
}

.page-about .phase-index-title {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .phase-index ol {
  list-style: none;
  margin: 0 0 12px;
  padding: 0;
  display: flex;
  gap: 0;
  overflow-x: auto;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.page-about .phase-index a {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 11px 14px;
  border-right: 1px solid var(--line);
  white-space: nowrap;
  text-decoration: none;
  color: var(--muted);
  font-size: 13px;
  transition: color var(--dur-fast) var(--ease);
}

.page-about .phase-index a .idx {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--orange);
  letter-spacing: 0.06em;
}

.page-about .phase-index a:hover,
.page-about .phase-index a:focus-visible {
  color: var(--cyan);
}

.page-about .phase-index-note {
  margin: 0;
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
}

.page-about .phase-index-note a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid var(--cyan-dim);
}

.page-about .phase {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 18px;
  padding: 26px 0 30px;
  border-top: 1px solid var(--line);
}

.page-about .phase:last-child {
  border-bottom: 1px solid var(--line);
}

.page-about .phase h2 {
  font-family: var(--font-display);
  font-size: clamp(22px, 3vw, 30px);
  line-height: 1.2;
  letter-spacing: -0.01em;
  color: var(--ink);
  margin: 8px 0 12px;
}

.page-about .phase p {
  margin: 0 0 12px;
  color: var(--ink);
  max-width: 62ch;
}

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

.page-about .phase-metric {
  background: var(--orange);
  color: var(--bg-deep);
  padding: 14px 16px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 6px;
  align-self: start;
}

.page-about .metric-num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 28px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.03em;
}

.page-about .metric-label {
  font-size: 12px;
  line-height: 1.5;
  letter-spacing: 0.02em;
}

/* ===== 时间刻度带 ===== */
.page-about .timeline-band {
  margin: 42px 0 48px;
  padding: 16px 2px 14px;
  border-top: 1px solid var(--cyan-dim);
  border-bottom: 1px solid var(--line);
  background-image: repeating-linear-gradient(90deg, var(--line) 0 1px, transparent 1px 22px);
  background-repeat: repeat-x;
  background-size: auto 8px;
  background-position: left bottom;
}

.page-about .timeline-band ol {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 10px 0;
}

.page-about .timeline-band li {
  flex: 1 1 46%;
  padding-left: 10px;
  border-left: 2px solid var(--cyan);
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.page-about .timeline-band .tick {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--orange);
  margin-right: 6px;
}

/* ===== 团队 ===== */
.page-about .about-team .section-desc {
  max-width: 62ch;
}

.page-about .team-connector {
  display: none;
  width: 100%;
  height: 44px;
  margin: 26px 0 -6px;
}

.page-about .team-grid {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
}

.page-about .team-grid > li {
  border-top: 2px solid var(--cyan);
  padding: 16px 0 20px;
}

.page-about .team-role {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-size: 19px;
  color: var(--ink);
  letter-spacing: 0.01em;
}

.page-about .team-desc {
  margin: 0 0 12px;
  font-size: 15px;
  line-height: 1.75;
  color: var(--ink);
}

.page-about .team-meta {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

/* ===== 校对流程 ===== */
.page-about .about-check {
  margin-top: 56px;
}

.page-about .about-check .section-desc {
  max-width: 62ch;
}

.page-about .check-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 26px;
  margin-top: 26px;
  align-items: start;
}

.page-about .check-flow {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
}

.page-about .flow-node {
  position: relative;
  padding: 18px 4px 18px 20px;
  border-top: 1px solid var(--line);
  transition: border-color var(--dur-fast) var(--ease), background-color var(--dur-fast) var(--ease);
}

.page-about .flow-node::before {
  content: "";
  position: absolute;
  top: -4px;
  left: 0;
  width: 7px;
  height: 7px;
  background: var(--cyan);
}

.page-about .flow-node:hover,
.page-about .flow-node:focus-visible {
  border-top-color: var(--cyan);
  background: var(--surface);
  outline: none;
}

.page-about .flow-time {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 24px;
  letter-spacing: -0.02em;
  color: var(--orange);
}

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

.page-about .flow-detail {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
  transition: color var(--dur-fast) var(--ease);
}

.page-about .flow-node:hover .flow-detail,
.page-about .flow-node:focus-visible .flow-detail {
  color: var(--ink);
}

.page-about .check-media {
  margin: 0;
}

.page-about .check-media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 10 / 7;
  object-fit: cover;
  border: 1px solid var(--line);
}

.page-about .check-note {
  margin: 24px 0 0;
  padding: 14px 16px;
  border-left: 2px solid var(--orange);
  background: var(--surface);
  font-size: 14px;
  line-height: 1.8;
  color: var(--ink);
}

.page-about .check-note a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid var(--cyan-dim);
}

/* ===== 覆盖范围 ===== */
.page-about .about-coverage {
  margin-top: 56px;
}

.page-about .coverage-banner {
  margin: 0 0 26px;
}

.page-about .coverage-banner img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 14 / 5;
  object-fit: cover;
  border: 1px solid var(--line);
}

.page-about .about-coverage .section-desc {
  max-width: 62ch;
}

.page-about .tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 0;
  margin-top: 24px;
  border-bottom: 1px solid var(--line);
}

.page-about .tabs [role="tab"] {
  appearance: none;
  background: transparent;
  border: 1px solid var(--line);
  border-bottom: 0;
  color: var(--muted);
  font-family: var(--font-body);
  font-size: 13px;
  letter-spacing: 0.06em;
  padding: 11px 18px;
  cursor: pointer;
  transition: color var(--dur-fast) var(--ease), background-color var(--dur-fast) var(--ease), border-color var(--dur-fast) var(--ease);
}

.page-about .tabs [role="tab"] + [role="tab"] {
  border-left: 0;
}

.page-about .tabs [role="tab"]:hover {
  color: var(--cyan);
}

.page-about .tabs [role="tab"][aria-selected="true"] {
  background: var(--cyan);
  border-color: var(--cyan);
  color: var(--bg-deep);
}

.page-about .tabs [role="tab"]:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 1px;
}

.page-about .cov-panel {
  border: 1px solid var(--line);
  border-top: 0;
  background: var(--surface);
  padding: 18px 18px 6px;
}

.page-about .cov-panel:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 1px;
}

.page-about .cov-list {
  margin: 0;
}

.page-about .cov-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 4px;
  padding: 12px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .cov-row:last-child {
  border-bottom: 0;
}

.page-about .cov-row dt {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--orange);
}

.page-about .cov-row dd {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--ink);
}

.page-about .coverage-note {
  margin: 18px 0 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .coverage-note a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid var(--cyan-dim);
}

/* ===== 栏目收敛 ===== */
.page-about .about-focus {
  margin-top: 56px;
}

.page-about .about-focus .section-desc {
  max-width: 62ch;
}

.page-about .focus-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
  margin-top: 26px;
  border-top: 1px solid var(--line);
}

.page-about .focus-col {
  padding: 20px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .focus-num {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--orange);
}

.page-about .focus-title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-size: 19px;
  color: var(--ink);
}

.page-about .focus-col p:not(.focus-num) {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--muted);
}

.page-about .focus-note {
  margin: 18px 0 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .focus-note a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid var(--cyan-dim);
}

/* ===== 下一步 ===== */
.page-about .about-next {
  margin: 56px 0 0;
  padding: 26px 20px 28px;
  background: var(--bg-deep);
  border-left: 2px solid var(--cyan);
}

.page-about .about-next h2 {
  font-family: var(--font-display);
  font-size: clamp(22px, 3.2vw, 30px);
  line-height: 1.2;
  color: var(--ink);
  margin: 8px 0 12px;
}

.page-about .about-next p {
  margin: 0 0 20px;
  max-width: 58ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .next-actions {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
}

.page-about .next-actions .btn {
  text-align: center;
  text-decoration: none;
}

/* ===== 响应式 ===== */
@media (min-width: 700px) {
  .page-about .about-hero-facts {
    max-width: 520px;
  }

  .page-about .phase-index a {
    padding: 11px 18px;
  }

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

  .page-about .flow-node {
    padding: 18px 16px 18px 16px;
    border-top: 1px solid var(--line);
  }

  .page-about .cov-row {
    grid-template-columns: 150px minmax(0, 1fr);
    gap: 16px;
    align-items: baseline;
  }

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

@media (min-width: 900px) {
  .page-about .about-hero {
    grid-template-columns: minmax(0, 1fr) 320px;
    gap: 44px;
  }

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

  .page-about .phase {
    grid-template-columns: minmax(0, 1fr) var(--about-metric);
    gap: 30px;
  }

  .page-about .check-layout {
    grid-template-columns: minmax(0, 1fr) minmax(0, 380px);
    gap: 36px;
  }

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

  .page-about .focus-col {
    padding: 22px 22px 22px 0;
    border-bottom: 0;
    border-right: 1px solid var(--line);
  }

  .page-about .focus-col:last-child {
    border-right: 0;
    padding-right: 0;
  }

  .page-about .focus-col + .focus-col {
    padding-left: 22px;
  }
}

@media (min-width: 1024px) {
  .page-about .about-body {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: 48px;
    margin-top: 64px;
  }

  .page-about .phase-index {
    position: sticky;
    top: 104px;
    align-self: start;
  }

  .page-about .phase-index ol {
    display: block;
    border-top: 0;
    border-bottom: 0;
    border-left: 1px solid var(--line);
    overflow: visible;
    margin-bottom: 16px;
  }

  .page-about .phase-index a {
    display: grid;
    grid-template-columns: 26px minmax(0, 1fr);
    gap: 8px;
    padding: 13px 0 13px 16px;
    border-right: 0;
    border-bottom: 0;
    white-space: normal;
    line-height: 1.5;
  }

  .page-about .phase-index a:hover,
  .page-about .phase-index a:focus-visible {
    box-shadow: inset 2px 0 0 var(--cyan);
  }

  .page-about .timeline-band {
    margin: 52px 0 60px;
  }

  .page-about .timeline-band li {
    flex: 1 1 0;
    font-size: 14px;
  }

  .page-about .team-connector {
    display: block;
  }

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

  .page-about .team-grid > li {
    padding: 18px 22px 22px 0;
  }

  .page-about .team-grid > li + li {
    border-left: 1px solid var(--line);
    padding-left: 22px;
  }

  .page-about .about-check,
  .page-about .about-coverage,
  .page-about .about-focus {
    margin-top: 68px;
  }

  .page-about .about-next {
    margin-top: 68px;
    padding: 32px 32px 34px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .flow-node,
  .page-about .flow-detail,
  .page-about .phase-index a,
  .page-about .tabs [role="tab"] {
    transition: none;
  }
}
<<<END>>>