.page-about {
  --about-rail: 280px;
}

.page-about .about-crumb {
  padding: 16px 0 4px;
  font-size: 13px;
  color: var(--stone);
}

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

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

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  color: var(--on-dark);
}

.page-about .about-hero-grid {
  display: grid;
  gap: 30px;
}

.page-about .about-kicker {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 0 0 18px;
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--on-dark-soft);
}

.page-about .about-kicker-dot {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--pitch);
  box-shadow: 0 0 0 4px rgba(47, 143, 78, 0.22);
}

.page-about .about-h1 {
  display: flex;
  flex-direction: column;
  gap: 0.06em;
  margin: 0;
  font-size: clamp(36px, 7vw, 72px);
  line-height: 1.02;
  letter-spacing: -0.02em;
  color: var(--sand);
}

.page-about .about-h1 span:last-child {
  color: var(--flood);
}

.page-about .about-lede {
  max-width: 36em;
  margin: 22px 0 0;
  font-size: clamp(16px, 1.5vw, 18px);
  line-height: 1.85;
  color: var(--on-dark);
}

.page-about .about-hero-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px 22px;
  margin: 28px 0 0;
}

.page-about .about-textlink {
  display: inline-block;
  padding-bottom: 2px;
  font-size: 14px;
  color: var(--sand);
  text-decoration: none;
  border-bottom: 1px solid rgba(244, 237, 226, 0.35);
}

.page-about .about-textlink:hover {
  color: var(--flood);
  border-bottom-color: var(--flood);
}

.page-about .about-textlink--dark {
  color: var(--on-dark);
}

.page-about .about-hero-side {
  padding: 20px 20px 18px;
  border: 1px solid rgba(27, 23, 18, 0.1);
  border-radius: var(--r-md);
  background: var(--glass);
  color: var(--ink);
  box-shadow: var(--shadow-1);
  -webkit-backdrop-filter: blur(6px);
  backdrop-filter: blur(6px);
}

.page-about .about-side-title {
  margin: 0 0 12px;
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--stone);
}

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

.page-about .about-toc .toc-link {
  display: block;
  padding: 9px 10px;
  font-size: 14px;
  line-height: 1.45;
  color: var(--ink);
  text-decoration: none;
  border-left: 3px solid transparent;
  border-radius: 0 var(--r-sm) var(--r-sm) 0;
  transition: background-color 160ms var(--ease), border-color 160ms var(--ease);
}

.page-about .about-toc .toc-link:hover {
  background: rgba(47, 143, 78, 0.12);
}

.page-about .about-toc .toc-link[aria-current] {
  font-weight: 700;
  background: rgba(47, 143, 78, 0.16);
  border-left-color: var(--pitch);
}

.page-about .about-hero-facts {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  margin: 18px 0 0;
  padding-top: 16px;
  border-top: 1px solid var(--line-soft);
}

.page-about .about-hero-facts dt {
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--stone);
}

.page-about .about-hero-facts dd {
  margin: 4px 0 0;
  font-family: var(--font-mono);
  font-size: clamp(20px, 2.2vw, 26px);
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--pitch-deep);
}

/* ---------- 章节通用 ---------- */

.page-about .about-head {
  margin-bottom: 26px;
}

.page-about h2 {
  margin: 10px 0 0;
  font-size: clamp(24px, 3.2vw, 38px);
  line-height: 1.22;
  letter-spacing: -0.01em;
  color: var(--ink);
}

.page-about .about-body p {
  max-width: 38em;
  margin: 0 0 1.05em;
  font-size: 16px;
  line-height: 1.85;
  color: var(--stone);
}

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

.page-about .about-body a {
  color: var(--sky);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .about-split {
  display: grid;
  gap: 26px;
}

.page-about .about-rail {
  display: grid;
  gap: 20px;
  align-content: start;
}

.page-about .about-aside {
  padding: 18px 18px 16px;
  border-left: 3px solid var(--pitch);
  border-radius: 0 var(--r-sm) var(--r-sm) 0;
  background: var(--sand-lift);
}

.page-about .about-aside-title {
  margin: 0 0 12px;
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--stone);
}

.page-about .about-aside-list {
  display: grid;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-aside-list li {
  position: relative;
  padding-left: 16px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--ink);
}

.page-about .about-aside-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 9px;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--flood);
}

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

.page-about .about-media img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: var(--r-md);
  object-fit: cover;
}

.page-about .about-media figcaption {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--stone);
}

.page-about .about-media--band {
  margin-top: 32px;
}

/* ---------- 深色带内的适配 ---------- */

.page-about .band-dark h2,
.page-about .band-dark h3 {
  color: var(--sand);
}

.page-about .band-dark .section-note,
.page-about .band-dark .about-media figcaption {
  color: var(--on-dark-soft);
}

.page-about .band-dark .about-body p {
  color: var(--on-dark);
}

.page-about .band-dark .about-aside {
  background: var(--ink-2);
  border-left-color: var(--flood);
}

.page-about .band-dark .about-aside-title {
  color: var(--on-dark-soft);
}

.page-about .band-dark .about-aside-list li {
  color: var(--on-dark);
}

/* ---------- 年份时间轴 ---------- */

.page-about .about-year-jump {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0 0 30px;
}

.page-about .about-year-jump a {
  padding: 6px 13px;
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--sand);
  text-decoration: none;
  border: 1px solid var(--line-dark);
  border-radius: var(--r-sm);
  transition: background-color 160ms var(--ease), color 160ms var(--ease), border-color 160ms var(--ease);
}

.page-about .about-year-jump a:hover {
  color: var(--ink);
  background: var(--flood);
  border-color: var(--flood);
}

.page-about .about-track {
  position: relative;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-track::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: linear-gradient(180deg, var(--pitch), rgba(242, 121, 43, 0.65));
}

.page-about .about-track-item {
  position: relative;
  padding: 0 0 32px 34px;
}

.page-about .about-track-item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 6px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--pitch);
  border: 3px solid var(--ink);
  box-sizing: border-box;
}

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

.page-about .about-track-year {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: clamp(22px, 3vw, 30px);
  font-weight: 700;
  line-height: 1;
  color: var(--flood);
}

.page-about .about-track-body h3 {
  margin: 0 0 8px;
  font-size: 18px;
  line-height: 1.4;
}

.page-about .about-track-body p {
  max-width: 40em;
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--on-dark);
}

/* ---------- 速度图表 ---------- */

.page-about .about-chart-wrap {
  padding: 18px 14px 10px;
  border: 1px solid var(--line-soft);
  border-radius: var(--r-md);
  background: var(--sand-lift);
}

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

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

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

.page-about .about-chart .trend {
  fill: none;
  stroke: var(--pitch);
  stroke-width: 3;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.page-about .about-chart .trend-dot {
  fill: var(--flood);
}

.page-about .about-chart .target {
  stroke: var(--flood);
  stroke-width: 2;
  stroke-dasharray: 6 5;
}

.page-about .about-chart .target-label {
  fill: var(--flood);
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
}

/* ---------- 合作 ---------- */

.page-about .about-partners {
  display: grid;
  gap: 16px;
}

.page-about .about-partner {
  padding: 20px;
  border: 1px solid var(--line-soft);
  border-radius: var(--r-md);
  background: var(--sand-lift);
  transition: transform 200ms var(--ease), border-color 200ms var(--ease);
}

.page-about .about-partner:hover {
  transform: translateY(-2px);
  border-color: var(--pitch);
}

.page-about .about-partner h3 {
  margin: 12px 0 8px;
  font-size: 18px;
  line-height: 1.4;
  color: var(--ink);
}

.page-about .about-partner p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--stone);
}

.page-about .about-partner-cta {
  max-width: 46em;
  margin: 26px 0 0;
  padding-top: 20px;
  font-size: 15px;
  line-height: 1.85;
  color: var(--stone);
  border-top: 1px solid var(--line-soft);
}

.page-about .about-partner-cta a {
  color: var(--sky);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ---------- 承诺 ---------- */

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

.page-about .about-promise li {
  display: grid;
  gap: 6px 22px;
  padding: 22px 0;
  border-top: 1px solid var(--line-ink);
}

.page-about .about-promise-num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 26px;
  font-weight: 700;
  line-height: 1.1;
  color: var(--pitch);
}

.page-about .about-promise h3 {
  margin: 0;
  font-size: 18px;
  line-height: 1.45;
  color: var(--ink);
}

.page-about .about-promise p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--stone);
}

/* ---------- 收尾 ---------- */

.page-about .about-cta {
  display: grid;
  gap: 16px;
  margin-top: 40px;
  padding: 28px 24px;
  border-radius: var(--r-lg);
  background: var(--ink);
}

.page-about .about-cta h3 {
  margin: 0 0 8px;
  font-size: clamp(20px, 2.4vw, 26px);
  line-height: 1.35;
  color: var(--sand);
}

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

.page-about .about-cta-links {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px 20px;
}

.page-about .about-cta .about-textlink {
  color: var(--sand);
  border-bottom-color: rgba(244, 237, 226, 0.35);
}

.page-about .about-cta .about-textlink:hover {
  color: var(--flood);
  border-bottom-color: var(--flood);
}

/* ---------- 断点 ---------- */

@media (min-width: 760px) {
  .page-about .about-track::before {
    left: 96px;
  }

  .page-about .about-track-item {
    display: grid;
    grid-template-columns: 96px minmax(0, 1fr);
    gap: 0 24px;
    padding: 0 0 38px 0;
  }

  .page-about .about-track-item::before {
    left: 88px;
    top: 4px;
  }

  .page-about .about-track-year {
    margin: 0;
    text-align: right;
  }

  .page-about .about-promise li {
    grid-template-columns: 64px minmax(0, 1fr) minmax(0, 300px);
    align-items: start;
    padding: 26px 0;
  }

  .page-about .about-promise-num {
    font-size: 30px;
  }

  .page-about .about-partners {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 20px;
  }
}

@media (min-width: 920px) {
  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 1.45fr) minmax(0, 1fr);
    gap: 56px;
    align-items: start;
  }

  .page-about .about-split {
    grid-template-columns: minmax(0, 1fr) var(--about-rail);
    gap: 48px;
    align-items: start;
  }

  .page-about .about-split--flip {
    grid-template-columns: 360px minmax(0, 1fr);
  }

  .page-about .about-split--flip .about-rail {
    order: -1;
  }

  .page-about .about-cta {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    gap: 24px;
    padding: 34px 38px;
  }

  .page-about .about-cta-links {
    justify-content: flex-end;
  }
}
<<<END>>>