.page-about {
  --about-rail: 72px;
  background: var(--dawn);
  color: var(--ink);
  font-family: var(--font-sans);
  -webkit-font-smoothing: antialiased;
}

.page-about .num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
}

/* ============ 首屏 ============ */
.page-about .about-hero {
  background: var(--lake);
  color: #fff;
  padding: clamp(56px, 8vw, 96px) 0 clamp(48px, 7vw, 88px);
}

.page-about .breadcrumb {
  margin: 0 0 clamp(28px, 5vw, 52px);
}

.page-about .breadcrumb a {
  color: rgba(255, 255, 255, 0.82);
  text-decoration: none;
}

.page-about .breadcrumb a:hover {
  color: #fff;
}

.page-about .breadcrumb li {
  color: rgba(255, 255, 255, 0.6);
}

.page-about .about-hero__grid,
.page-about .about-chapter__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}

.page-about .vertical-note {
  margin: 0;
  font-size: 12px;
  line-height: 1.4;
  letter-spacing: 0.24em;
  color: var(--moss);
}

.page-about .about-hero .vertical-note {
  color: var(--sand);
}

.page-about .eyebrow {
  margin: 0 0 14px;
  font-size: 12px;
  letter-spacing: 0.28em;
  color: var(--rape);
}

.page-about .about-hero h1 {
  margin: 0 0 20px;
  font-size: clamp(32px, 5.2vw, 62px);
  font-weight: 900;
  line-height: 1.2;
  letter-spacing: -0.02em;
  max-width: 15em;
}

.page-about .about-lede {
  margin: 0 0 30px;
  max-width: 30em;
  font-size: clamp(16px, 1.6vw, 18px);
  line-height: 1.78;
  color: rgba(255, 255, 255, 0.88);
}

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

.page-about .about-hero .btn--ghost {
  border-color: rgba(255, 255, 255, 0.52);
  color: #fff;
}

.page-about .about-hero .btn--ghost:hover {
  background: rgba(255, 255, 255, 0.14);
  border-color: #fff;
}

/* ============ 章节导航 ============ */
.page-about .about-jump {
  background: var(--lake-mist);
  padding: 16px 0;
}

.page-about .about-jump__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 14px;
}

.page-about .about-jump__label {
  font-size: 12px;
  letter-spacing: 0.24em;
  color: var(--lake-deep);
  flex: 0 0 auto;
}

.page-about .about-jump__list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-jump__link {
  display: inline-block;
  padding: 6px 16px;
  font-size: 14px;
  line-height: 1.6;
  text-decoration: none;
  color: var(--ink);
  background: rgba(255, 255, 255, 0.72);
  border: 1px solid transparent;
  border-radius: var(--radius-pill);
  transition: background-color 160ms ease, border-color 160ms ease;
}

.page-about .about-jump__link:hover,
.page-about .about-jump__link:focus-visible {
  background: #fff;
  border-color: var(--lake);
}

/* ============ 章节通用 ============ */
.page-about .about-chapter {
  padding: clamp(56px, 9vw, 112px) 0;
}

.page-about .about-chapter--mist {
  background: var(--lake-mist);
}

.page-about .about-chapter--sand {
  background: var(--rape-soft);
}

.page-about .about-chapter__body {
  max-width: 34em;
}

.page-about .about-chapter__num {
  display: block;
  margin: 0 0 10px;
  font-size: clamp(40px, 5.5vw, 64px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0.04em;
  color: var(--lake);
  opacity: 0.42;
}

.page-about .about-chapter__title {
  margin: 0 0 24px;
  font-size: clamp(25px, 3.4vw, 40px);
  font-weight: 800;
  line-height: 1.34;
  letter-spacing: -0.01em;
  color: var(--ink);
}

.page-about .about-prose {
  font-size: 17px;
  line-height: 1.88;
  color: var(--rock);
}

.page-about .about-prose p {
  margin: 0 0 1.15em;
}

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

/* ============ 通栏图片 ============ */
.page-about .about-band {
  margin: 0;
  padding: 0 0 clamp(8px, 2vw, 24px);
}

.page-about .about-band__frame {
  position: relative;
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--lake-deep);
}

.page-about .about-band__frame img {
  display: block;
  width: 100%;
  height: clamp(200px, 36vw, 400px);
  object-fit: cover;
}

.page-about .about-band__frame figcaption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  margin: 0;
  padding: 14px 20px;
  font-size: 13px;
  line-height: 1.6;
  color: #fff;
  background: rgba(10, 67, 86, 0.74);
}

/* ============ 半幅图片 ============ */
.page-about .about-figure {
  margin: 0;
  padding: 0 0 clamp(40px, 7vw, 88px);
}

.page-about .about-figure__inner {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.page-about .about-figure__frame {
  border-radius: var(--radius-md);
  overflow: hidden;
  background: var(--lake-mist);
}

.page-about .about-figure__frame img {
  display: block;
  width: 100%;
  height: clamp(200px, 34vw, 360px);
  object-fit: cover;
}

.page-about .about-figure__caption {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--rock);
}

/* ============ 数据条 ============ */
.page-about .about-stats {
  display: flex;
  flex-wrap: wrap;
  gap: 22px 44px;
  margin: 36px 0 0;
  padding: 26px 30px;
  border-radius: var(--radius-lg);
  background: var(--lake);
  color: #fff;
}

.page-about .about-stat {
  min-width: 88px;
}

.page-about .about-stat__value {
  display: block;
  font-size: 34px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0.04em;
  color: var(--rape);
}

.page-about .about-stat__label {
  display: block;
  margin-top: 8px;
  font-size: 14px;
  color: rgba(255, 255, 255, 0.82);
}

/* ============ 阶段刻度 ============ */
.page-about .about-stages {
  margin: 30px 0 0;
  padding: 0;
  list-style: none;
  border-left: 2px solid var(--lake-mist);
}

.page-about .about-stage {
  position: relative;
  padding: 0 0 22px 22px;
  outline-offset: 4px;
}

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

.page-about .about-stage::before {
  content: "";
  position: absolute;
  left: -7px;
  top: 8px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--sand);
  transition: background-color 160ms ease, transform 160ms ease;
}

.page-about .about-stage:hover::before,
.page-about .about-stage:focus-visible::before {
  background: var(--ember);
  transform: scale(1.25);
}

.page-about .about-stage__num {
  display: inline-block;
  margin-right: 10px;
  font-size: 20px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--lake);
}

.page-about .about-stage__title {
  font-size: 18px;
  font-weight: 700;
  color: var(--ink);
}

.page-about .about-stage__note {
  display: block;
  margin-top: 6px;
  font-size: 15px;
  line-height: 1.75;
  color: var(--rock);
}

/* ============ 三类使用者 ============ */
.page-about .about-audience {
  margin: 30px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-audience__row {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px 16px;
  padding: 22px 0;
  border-top: 1px solid rgba(15, 110, 140, 0.22);
}

.page-about .about-audience__row:last-child {
  border-bottom: 1px solid rgba(15, 110, 140, 0.22);
}

.page-about .about-audience__idx {
  flex: 0 0 auto;
  font-size: 22px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--lake);
  opacity: 0.55;
}

.page-about .about-audience__text {
  flex: 1 1 260px;
}

.page-about .about-audience__text h3 {
  margin: 0 0 6px;
  font-size: 19px;
  font-weight: 800;
  line-height: 1.4;
  color: var(--ink);
}

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

.page-about .about-audience__go {
  flex: 0 0 auto;
  font-size: 15px;
  font-weight: 700;
  text-decoration: none;
  color: var(--lake);
  border-bottom: 2px solid rgba(15, 110, 140, 0.28);
  padding-bottom: 2px;
  transition: color 160ms ease, border-color 160ms ease;
}

.page-about .about-audience__go:hover,
.page-about .about-audience__go:focus-visible {
  color: var(--ember);
  border-color: var(--ember);
}

/* ============ 收尾 ============ */
.page-about .about-cta {
  background: var(--lake-deep);
  color: #fff;
  padding: clamp(48px, 7vw, 84px) 0;
}

.page-about .about-cta__inner {
  display: flex;
  flex-direction: column;
  gap: 26px;
}

.page-about .about-cta__text h2 {
  margin: 0 0 14px;
  font-size: clamp(23px, 3vw, 34px);
  font-weight: 800;
  line-height: 1.36;
  letter-spacing: -0.01em;
}

.page-about .about-cta__text p {
  margin: 0;
  max-width: 32em;
  font-size: 16px;
  line-height: 1.8;
  color: rgba(255, 255, 255, 0.84);
}

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

.page-about .about-cta .btn--ghost {
  border-color: rgba(255, 255, 255, 0.5);
  color: #fff;
}

.page-about .about-cta .btn--ghost:hover {
  background: rgba(255, 255, 255, 0.14);
  border-color: #fff;
}

/* ============ 桌面端 ============ */
@media (min-width: 800px) {
  .page-about .about-hero__grid,
  .page-about .about-chapter__grid {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: clamp(20px, 3vw, 44px);
  }

  .page-about .about-hero__grid {
    align-items: start;
  }

  .page-about .about-chapter__grid {
    align-items: start;
  }

  .page-about .vertical-note {
    writing-mode: vertical-rl;
    text-orientation: mixed;
    letter-spacing: 0.34em;
    line-height: 1;
    position: sticky;
    top: 104px;
    align-self: start;
  }

  .page-about .about-hero .vertical-note {
    position: static;
  }

  .page-about .about-figure__inner {
    flex-direction: row;
    align-items: flex-start;
    justify-content: flex-end;
    gap: 28px;
  }

  .page-about .about-figure__frame {
    flex: 0 1 60%;
  }

  .page-about .about-figure__caption {
    flex: 0 1 30%;
    padding-top: 8px;
  }

  .page-about .about-cta__inner {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
    gap: 48px;
  }

  .page-about .about-cta__actions {
    flex: 0 0 auto;
  }

  .page-about .about-stage__note {
    max-height: 0;
    overflow: hidden;
    opacity: 0;
    transition: max-height 200ms ease, opacity 180ms ease, margin-top 200ms ease;
  }

  .page-about .about-stage:hover .about-stage__note,
  .page-about .about-stage:focus-visible .about-stage__note {
    max-height: 6em;
    opacity: 1;
    margin-top: 8px;
  }
}

@media (min-width: 1100px) {
  .page-about .about-stats {
    padding: 30px 38px;
    gap: 26px 60px;
  }

  .page-about .about-band__frame img {
    height: clamp(280px, 32vw, 440px);
  }
}
<<<END>>>