.page-about {
  background: var(--c-white);
  color: var(--c-ink);
  font-family: var(--font-body);
  padding-inline: var(--shell-pad);
  overflow-x: clip;
}

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

.page-about .about-hero,
.page-about .about-index,
.page-about .about-chapter,
.page-about .about-cta {
  max-width: var(--shell-max);
  margin-inline: auto;
}

/* ---------------- 首屏 ---------------- */
.page-about .about-hero {
  padding-block: clamp(120px, 16vw, 196px) clamp(30px, 4vw, 52px);
}

.page-about .about-hero__top {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 24px;
  margin-bottom: clamp(24px, 4vw, 44px);
}

.page-about .about-hero__kicker {
  margin: 0;
  font-size: 12.5px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--c-note);
}

.page-about .about-hero .breadcrumbs {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  color: var(--c-note);
}

.page-about .about-hero .breadcrumbs a {
  color: var(--c-note);
  text-decoration: none;
}

.page-about .about-hero .breadcrumbs a:hover {
  color: var(--c-orange-deep);
}

.page-about .about-hero .breadcrumbs__sep {
  color: var(--c-line-strong);
}

.page-about .about-hero .breadcrumbs__item {
  color: var(--c-ink-2);
}

.page-about .about-hero__title {
  font-family: var(--font-display);
  font-size: clamp(36px, 6.2vw, 80px);
  font-weight: 900;
  line-height: 1.08;
  letter-spacing: -0.03em;
  color: var(--c-ink);
  max-width: 17ch;
  margin: 0 0 clamp(20px, 3vw, 32px);
}

.page-about .about-hero__lead {
  font-size: clamp(16.5px, 1.9vw, 19px);
  line-height: 1.85;
  color: var(--c-note);
  max-width: 60ch;
  margin: 0;
}

.page-about .about-hero__facts {
  list-style: none;
  margin: clamp(26px, 4vw, 40px) 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px 12px;
}

.page-about .about-fact {
  display: inline-flex;
  align-items: center;
  padding: 7px 14px;
  font-size: 12.5px;
  letter-spacing: 0.06em;
  color: var(--c-ink-2);
  background: var(--c-paper);
  border: 1px solid var(--c-line);
  border-left: 3px solid var(--c-orange);
}

/* ---------------- 章节目录 ---------------- */
.page-about .about-index {
  padding-block: clamp(16px, 2.5vw, 22px);
  border-top: 1px solid var(--c-line);
  border-bottom: 1px solid var(--c-line);
}

.page-about .about-index__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 6px 8px;
}

.page-about .about-index__link {
  display: inline-block;
  padding: 6px 11px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.05em;
  color: var(--c-note);
  text-decoration: none;
  border: 1px solid transparent;
  transition: color 0.18s ease, border-color 0.18s ease, background-color 0.18s ease;
}

.page-about .about-index__link:hover,
.page-about .about-index__link:focus-visible {
  color: var(--c-ink);
  border-color: var(--c-line);
  background: var(--c-paper);
}

.page-about .about-index__link[aria-current] {
  color: var(--c-ink);
  border-color: var(--c-orange);
  background: var(--c-orange-soft);
}

/* ---------------- 章节骨架 ---------------- */
.page-about .about-chapter {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  padding-block: clamp(46px, 6.5vw, 92px);
  border-top: 1px solid var(--c-line);
}

.page-about .about-chapter:first-of-type {
  border-top: 0;
}

.page-about .about-rail {
  display: flex;
  align-items: baseline;
  gap: 10px;
}

.page-about .about-rail__num {
  font-size: clamp(26px, 3.4vw, 40px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--c-orange);
}

.page-about .about-rail__label {
  font-size: 12.5px;
  letter-spacing: 0.18em;
  color: var(--c-note);
}

.page-about .about-body {
  max-width: 68ch;
}

.page-about .about-chapter__title {
  font-family: var(--font-display);
  font-size: clamp(24px, 3vw, 38px);
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -0.02em;
  color: var(--c-ink);
  margin: 0 0 clamp(16px, 2.4vw, 26px);
}

.page-about .about-body > p {
  margin: 0 0 18px;
  font-size: clamp(16px, 1.5vw, 17.5px);
  line-height: 1.85;
  color: var(--c-ink-2);
}

.page-about .about-body > p:last-of-type {
  margin-bottom: 0;
}

/* ---------------- 批注侧栏 ---------------- */
.page-about .about-note {
  margin: clamp(22px, 3vw, 32px) 0 0;
  padding: 4px 0 4px 18px;
  border-left: 2px solid var(--c-orange);
  max-width: 56ch;
}

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

/* ---------------- 图片 ---------------- */
.page-about .about-figure {
  margin: clamp(26px, 3.5vw, 42px) 0;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border: 1px solid var(--c-line);
  box-shadow: 8px 8px 0 var(--c-paper);
}

.page-about .about-figure figcaption {
  margin-top: 14px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--c-note);
  padding-left: 14px;
  border-left: 1px solid var(--c-line-strong);
}

/* ---------------- 编号卡 ---------------- */
.page-about .about-codes {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  margin: clamp(24px, 3vw, 34px) 0 0;
  background: var(--c-line);
  border: 1px solid var(--c-line);
}

.page-about .about-code {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 4px 14px;
  padding: 14px 16px;
  background: var(--c-white);
}

.page-about .about-code__no {
  font-size: 12.5px;
  letter-spacing: 0.08em;
  color: var(--c-orange-deep);
}

.page-about .about-code__name {
  font-size: 15.5px;
  font-weight: 600;
  color: var(--c-ink);
}

/* ---------------- 状态列表 ---------------- */
.page-about .about-status {
  list-style: none;
  margin: clamp(22px, 3vw, 32px) 0;
  padding: 0;
  border-top: 1px solid var(--c-line);
}

.page-about .about-status__row {
  display: grid;
  grid-template-columns: 18px minmax(0, 1fr);
  gap: 6px 10px;
  align-items: baseline;
  padding: 16px 0;
  border-bottom: 1px solid var(--c-line);
}

.page-about .about-status__name {
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--c-ink);
}

.page-about .about-status__desc {
  grid-column: 2 / -1;
  font-size: 15px;
  line-height: 1.8;
  color: var(--c-note);
}

/* ---------------- 时间轴 ---------------- */
.page-about .about-timeline {
  list-style: none;
  margin: clamp(22px, 3vw, 32px) 0 0;
  padding: 0 0 0 26px;
  position: relative;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 10px;
  bottom: 8px;
  width: 1px;
  background: var(--c-line-strong);
}

.page-about .about-tl {
  position: relative;
  padding-bottom: clamp(24px, 3vw, 36px);
}

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

.page-about .about-tl::before {
  content: "";
  position: absolute;
  left: -26px;
  top: 6px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--c-white);
  border: 2px solid var(--c-orange);
}

.page-about .about-tl__num {
  display: block;
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--c-note);
  margin-bottom: 4px;
}

.page-about .about-tl__title {
  font-family: var(--font-display);
  font-size: clamp(18px, 2vw, 22px);
  font-weight: 700;
  line-height: 1.35;
  color: var(--c-ink);
  margin: 0 0 8px;
}

.page-about .about-tl__text {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--c-ink-2);
}

/* ---------------- 数据 ---------------- */
.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(24px, 3vw, 34px) 0;
  background: var(--c-line);
  border: 1px solid var(--c-line);
}

.page-about .about-stats .metric {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 18px 16px;
  background: var(--c-paper);
}

.page-about .about-stats .metric__num {
  font-size: clamp(22px, 2.6vw, 30px);
  font-weight: 700;
  line-height: 1;
  color: var(--c-ink);
}

.page-about .about-stats .metric__label {
  font-size: 13px;
  line-height: 1.6;
  color: var(--c-note);
}

/* ---------------- 收尾 ---------------- */
.page-about .about-cta {
  margin-top: clamp(40px, 6vw, 80px);
  margin-bottom: clamp(48px, 7vw, 96px);
  padding: clamp(30px, 5vw, 52px) clamp(22px, 4vw, 48px);
  background: var(--c-ink);
  border-left: 6px solid var(--c-orange);
}

.page-about .about-cta__title {
  font-family: var(--font-display);
  font-size: clamp(22px, 3vw, 34px);
  font-weight: 800;
  line-height: 1.25;
  letter-spacing: -0.02em;
  color: var(--c-white);
  margin: 0 0 14px;
}

.page-about .about-cta__text {
  margin: 0 0 clamp(22px, 3vw, 30px);
  font-size: 15.5px;
  line-height: 1.85;
  color: #C6D0DA;
  max-width: 56ch;
}

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

/* ---------------- 桌面栅格 ---------------- */
@media (min-width: 820px) {
  .page-about .about-chapter {
    grid-template-columns: 128px minmax(0, 1fr);
    gap: clamp(28px, 4vw, 56px);
  }

  .page-about .about-rail {
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
    position: sticky;
    top: calc(var(--header-h-sm) + 28px);
    align-self: start;
  }

  .page-about .about-rail__num {
    font-size: clamp(34px, 3.6vw, 48px);
  }

  .page-about .about-rail__label {
    writing-mode: horizontal-tb;
  }

  .page-about .about-status__row {
    grid-template-columns: 18px 140px minmax(0, 1fr);
    align-items: center;
    gap: 4px 16px;
  }

  .page-about .about-status__desc {
    grid-column: auto;
  }

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

  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 1100px) {
  .page-about .about-chapter {
    grid-template-columns: 168px minmax(0, 1fr) 216px;
    column-gap: clamp(32px, 4vw, 64px);
    row-gap: 22px;
  }

  .page-about .about-body {
    grid-column: 2;
  }

  .page-about .about-body > .about-note {
    grid-column: 3;
  }

  .page-about .about-note {
    margin-top: 0;
    position: sticky;
    top: calc(var(--header-h-sm) + 28px);
  }

  .page-about .about-chapter {
    grid-template-areas: "rail .page-about note";
  }

  .page-about .about-rail {
    grid-area: rail;
  }

  .page-about .about-body {
    grid-area: body;
  }
}
<<<END>>>