.page-about {
  --about-num-col: 64px;
  --about-note-col: 240px;
  background: var(--ink);
  color: var(--text);
  padding-bottom: 80px;
}

.page-about .breadcrumb {
  margin: 22px 0 0;
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  position: relative;
  margin-top: 20px;
  padding: 34px 20px 30px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-left: 3px solid var(--cyan);
}

.page-about .about-hero::before,
.page-about .about-hero::after {
  content: "";
  position: absolute;
  width: 14px;
  height: 14px;
  border: 1px solid var(--cyan);
  opacity: .55;
  pointer-events: none;
}

.page-about .about-hero::before {
  top: 10px;
  right: 10px;
  border-left: 0;
  border-bottom: 0;
}

.page-about .about-hero::after {
  bottom: 10px;
  right: 10px;
  border-left: 0;
  border-top: 0;
}

.page-about .hero-title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(28px, 7.2vw, 52px);
  line-height: 1.22;
  letter-spacing: .01em;
  margin: 14px 0 18px;
  color: var(--text);
  max-width: 20em;
}

.page-about .hero-lede {
  margin: 0 0 28px;
  font-size: 16px;
  line-height: 1.9;
  color: var(--muted);
  max-width: 56ch;
}

.page-about .hero-metrics {
  list-style: none;
  margin: 0;
  padding: 22px 0 0;
  border-top: 1px solid var(--line);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px 14px;
}

.page-about .hero-metric {
  display: flex;
  flex-direction: column;
  gap: 5px;
  min-width: 0;
}

.page-about .hero-metric-num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 25px;
  line-height: 1.1;
  font-weight: 700;
  color: var(--cyan);
  letter-spacing: -.01em;
}

.page-about .hero-metric:nth-child(even) .hero-metric-num {
  color: var(--orange);
}

.page-about .hero-metric-label {
  font-size: 13px;
  line-height: 1.5;
  color: var(--muted);
  letter-spacing: .02em;
}

/* ---------- 章节骨架 ---------- */

.page-about .chapter {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  padding: 38px 0 44px;
  border-top: 1px solid var(--line);
}

.page-about .chapter-num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 30px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--cyan);
  opacity: .78;
  margin: 0;
}

.page-about .chapter-title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(21px, 4.8vw, 34px);
  line-height: 1.32;
  letter-spacing: .01em;
  color: var(--text);
  margin: 0 0 16px;
  max-width: 22em;
}

.page-about .chapter-copy p {
  font-size: 16px;
  line-height: 1.92;
  color: var(--muted);
  margin: 0 0 16px;
  max-width: 60ch;
}

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

.page-about .chapter-tail {
  font-size: 15px;
  line-height: 1.9;
  color: var(--muted);
  margin: 24px 0 0;
  padding-top: 18px;
  border-top: 1px dashed var(--line);
  max-width: 62ch;
}

.page-about .about-link {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(34, 211, 238, .35);
  transition: border-color .2s var(--ease), color .2s var(--ease);
}

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

/* ---------- 章节边注 ---------- */

.page-about .chapter-note {
  border-top: 2px solid var(--line);
  padding-top: 12px;
}

.page-about .note-label {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--orange);
  margin: 0 0 8px;
}

.page-about .note-text {
  font-size: 14px;
  line-height: 1.85;
  color: var(--muted);
  margin: 0;
}

.page-about .note-text .about-link {
  color: var(--cyan);
}

/* ---------- 图片 ---------- */

.page-about .about-figure {
  margin: 24px 0 0;
  position: relative;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--line);
  background: var(--panel);
}

.page-about .about-figure-tag {
  position: absolute;
  left: 0;
  bottom: 0;
  padding: 6px 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--muted);
  background: var(--ink);
  border-top: 1px solid var(--line);
  border-right: 1px solid var(--line);
}

/* ---------- 三张岗位展签 ---------- */

.page-about .role-plates {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin-top: 22px;
}

.page-about .role-plate {
  background: var(--panel);
  border: 1px solid var(--line);
  border-top: 3px solid var(--role-accent, var(--cyan));
  padding: 20px 18px 22px;
  transition: transform .24s var(--ease), box-shadow .24s var(--ease);
}

.page-about .role-plate:hover,
.page-about .role-plate:focus-within {
  transform: translateY(-4px);
  box-shadow: 0 14px 32px rgba(0, 0, 0, .38);
}

.page-about .role-plate--data {
  --role-accent: var(--cyan);
}

.page-about .role-plate--schedule {
  --role-accent: var(--orange);
}

.page-about .role-plate--video {
  --role-accent: var(--violet);
}

.page-about .role-head {
  display: flex;
  align-items: baseline;
  gap: 4px;
  margin: 0 0 12px;
}

.page-about .role-count {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 30px;
  font-weight: 700;
  line-height: 1;
  color: var(--role-accent, var(--cyan));
}

.page-about .role-unit {
  font-size: 13px;
  color: var(--muted);
}

.page-about .role-name {
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 700;
  letter-spacing: .02em;
  color: var(--text);
  margin: 0 0 10px;
}

.page-about .role-text {
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--muted);
  margin: 0;
}

/* ---------- 覆盖范围 ---------- */

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

.page-about .coverage-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
  border-top: 1px solid var(--line);
}

.page-about .coverage-item {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 16px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .coverage-num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 30px;
  font-weight: 700;
  line-height: 1;
  color: var(--cyan);
  flex: 0 0 auto;
  min-width: 84px;
}

.page-about .coverage-item:nth-child(2) .coverage-num {
  color: var(--orange);
}

.page-about .coverage-item:nth-child(3) .coverage-num {
  color: var(--violet);
}

.page-about .coverage-label {
  font-size: 14px;
  line-height: 1.7;
  color: var(--muted);
}

/* ---------- 折线图 ---------- */

.page-about .about-chart {
  margin: 0;
  padding: 20px 16px 16px;
  background: var(--panel);
  border: 1px solid var(--line);
}

.page-about .about-chart-cap {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--orange);
  margin: 0 0 14px;
}

.page-about .about-chart-svg {
  display: block;
  width: 100%;
  height: auto;
  overflow: visible;
}

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

.page-about .chart-baseline {
  stroke: var(--muted);
  stroke-opacity: .5;
}

.page-about .chart-axis-text {
  font-family: var(--font-mono);
  font-size: 12px;
  fill: var(--muted);
}

.page-about .chart-area {
  fill: rgba(34, 211, 238, .1);
}

.page-about .chart-line {
  fill: none;
  stroke: var(--cyan);
  stroke-width: 2.5;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.page-about .chart-dot {
  fill: var(--ink);
  stroke: var(--cyan);
  stroke-width: 2;
  transition: r .18s var(--ease), fill .18s var(--ease), stroke .18s var(--ease);
}

.page-about .chart-dot:hover,
.page-about .chart-dot:focus {
  r: 7;
  fill: var(--orange);
  stroke: var(--orange);
  outline: none;
}

.page-about .about-chart-note {
  margin: 14px 0 0;
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
}

/* ---------- 纸张叠层自述 ---------- */

.page-about .paper-note {
  position: relative;
  margin: 28px 0 0;
  padding: 26px 22px 26px 24px;
  background: var(--paper);
  color: var(--ink);
  border-left: 5px solid var(--cyan);
  box-shadow: 8px 8px 0 0 var(--line);
}

.page-about .paper-note-label {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  color: #55637a;
  margin: 0 0 12px;
}

.page-about .paper-note-text {
  font-family: var(--font-display);
  font-size: 17px;
  line-height: 1.85;
  font-weight: 600;
  margin: 0;
  color: #14203a;
}

/* ---------- 中等屏幕 ---------- */

@media (min-width: 640px) {
  .page-about .about-hero {
    padding: 44px 36px 38px;
  }

  .page-about .hero-lede {
    font-size: 17px;
  }

  .page-about .hero-metrics {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 21px 18px;
  }

  .page-about .about-figure {
    margin-top: 28px;
  }

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

  .page-about .coverage-item {
    flex-direction: column;
    gap: 10px;
    border-top: 1px solid var(--line);
    border-bottom: 0;
    padding: 18px 16px 18px 0;
  }

  .page-about .coverage-num {
    min-width: 0;
  }

  .page-about .paper-note {
    padding: 32px 30px 32px 32px;
  }

  .page-about .paper-note-text {
    font-size: 19px;
  }
}

@media (min-width: 760px) {
  .page-about .role-plates {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 16px;
  }
}

/* ---------- 桌面端：编号 + 正文 + 边注三栏 ---------- */

@media (min-width: 1000px) {
  .page-about .about-hero {
    padding: 52px 52px 44px;
  }

  .page-about .chapter {
    grid-template-columns: var(--about-num-col) minmax(0, 1fr) var(--about-note-col);
    gap: 0 36px;
    padding: 58px 0 62px;
  }

  .page-about .chapter-num {
    font-size: 40px;
    position: sticky;
    top: 96px;
    align-self: start;
  }

  .page-about .chapter-note {
    align-self: start;
  }

  .page-about .about-chart {
    padding: 24px 22px 20px;
  }
}

@media (min-width: 1240px) {
  .page-about .chapter-title {
    font-size: 34px;
  }

  .page-about .chapter-copy p {
    font-size: 16.5px;
  }
}

/* ---------- 降低动效偏好 ---------- */

@media (prefers-reduced-motion: reduce) {
  .page-about .role-plate,
  .page-about .chart-dot,
  .page-about .about-link {
    transition: none;
  }

  .page-about .role-plate:hover,
  .page-about .role-plate:focus-within {
    transform: none;
  }

  .page-about .chapter-num {
    position: static;
  }
}
<<<END>>>