.page-about {
  --ab-line: rgba(78, 96, 112, .24);
  --ab-line-soft: rgba(78, 96, 112, .14);
  --ab-tint: rgba(231, 221, 202, .5);
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: var(--fs-body);
  line-height: 1.9;
  letter-spacing: .02em;
  overflow-x: hidden;
}

.page-about img { max-width: 100%; }

.page-about .ab-linkline {
  margin: 22px 0 0;
  font-size: 16px;
}
.page-about .ab-linkline a {
  color: var(--brick);
  text-decoration: none;
  border-bottom: 1px solid rgba(165, 67, 43, .4);
  padding-bottom: 2px;
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease);
}
.page-about .ab-linkline a:hover,
.page-about .ab-linkline a:focus-visible { color: var(--deep); border-color: var(--deep); }

/* ---------- 首屏封面 ---------- */
.page-about .ab-hero {
  background: var(--deep);
  color: var(--white);
  padding: clamp(32px, 6vw, 72px) 0 clamp(40px, 6vw, 76px);
  position: relative;
}
.page-about .ab-hero::after {
  content: "";
  position: absolute;
  inset: auto 0 0 0;
  height: 4px;
  background: linear-gradient(90deg, var(--brick) 0%, var(--brick) 12%, var(--brass) 12%, var(--brass) 18%, rgba(255,255,255,.08) 18%, rgba(255,255,255,.08) 100%);
}
.page-about .ab-hero__grid {
  display: grid;
  gap: 32px;
}
.page-about .ab-hero__kicker {
  margin: 0 0 18px;
  font-size: 12px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--brass);
}
.page-about .ab-hero__title {
  margin: 0 0 22px;
  font-family: var(--font-title);
  font-weight: 800;
  font-size: clamp(38px, 7.4vw, 76px);
  line-height: 1.14;
  letter-spacing: -.015em;
}
.page-about .ab-hero__intro {
  margin: 0 0 28px;
  max-width: 34em;
  font-size: var(--fs-lead);
  font-weight: 300;
  line-height: 1.85;
  color: rgba(244, 239, 230, .86);
}
.page-about .ab-btn-ghost {
  border-color: rgba(244, 239, 230, .4);
  color: var(--paper);
}
.page-about .ab-btn-ghost:hover,
.page-about .ab-btn-ghost:focus-visible {
  border-color: var(--brass);
  color: var(--brass);
}

.page-about .ab-facts {
  margin: 0;
  border-top: 1px solid rgba(244, 239, 230, .22);
}
.page-about .ab-facts__row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  padding: 12px 0;
  border-bottom: 1px solid rgba(244, 239, 230, .14);
}
.page-about .ab-facts dt {
  margin: 0;
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--brass);
}
.page-about .ab-facts dd {
  margin: 0;
  font-family: var(--font-title);
  font-size: 18px;
  font-weight: 500;
  color: var(--white);
}

/* ---------- 通栏主视觉 ---------- */
.page-about .ab-figure {
  display: block;
  position: relative;
  overflow: hidden;
  margin: 0;
  border-radius: var(--radius-lg);
  background: var(--paper-old);
}
.page-about .ab-figure img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.page-about .ab-figure--cover { aspect-ratio: 15 / 8; }
.page-about .ab-figure--4x3 { aspect-ratio: 10 / 7; margin-top: 28px; }
.page-about .ab-cover {
  border-radius: 0;
  margin: 0;
}

/* ---------- 正文骨架 ---------- */
.page-about .ab-body {
  padding: var(--space-section) 0 0;
}
.page-about .ab-body__grid {
  display: grid;
  gap: 36px;
}

/* ---------- 左侧刻度栏 ---------- */
.page-about .ab-rail {
  border-left: 1px solid var(--ab-line);
  padding-left: 20px;
}
.page-about .ab-rail__label {
  margin: 0 0 14px -21px;
  padding-left: 21px;
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--mist);
}
.page-about .ab-rail__list {
  list-style: none;
  margin: 0;
  padding: 0;
}
.page-about .ab-tick { position: relative; }
.page-about .ab-tick__link {
  display: block;
  position: relative;
  padding: 8px 0 10px;
  text-decoration: none;
  color: var(--mist);
  transition: color var(--dur) var(--ease);
}
.page-about .ab-tick__link::before {
  content: "";
  position: absolute;
  left: -25px;
  top: 15px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--paper);
  border: 1px solid var(--pale);
  transition: background var(--dur) var(--ease), border-color var(--dur) var(--ease);
}
.page-about .ab-tick__link:hover,
.page-about .ab-tick__link:focus-visible { color: var(--deep); }
.page-about .ab-tick__link:hover::before,
.page-about .ab-tick__link:focus-visible::before {
  background: var(--brick);
  border-color: var(--brick);
}
.page-about .ab-tick__year {
  display: block;
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--brick);
}
.page-about .ab-tick__name {
  display: block;
  font-family: var(--font-title);
  font-size: 15px;
  font-weight: 500;
  line-height: 1.5;
}
.page-about .ab-tick__pop {
  display: block;
  font-size: 12px;
  line-height: 1.6;
  color: var(--brass);
  opacity: 0;
  max-height: 0;
  overflow: hidden;
  transition: opacity var(--dur) var(--ease), max-height var(--dur) var(--ease);
}
.page-about .ab-tick__link:hover .ab-tick__pop,
.page-about .ab-tick__link:focus-visible .ab-tick__pop {
  opacity: 1;
  max-height: 4em;
}

/* ---------- 章节 ---------- */
.page-about .ab-sec { padding-bottom: clamp(40px, 6vw, 72px); }
.page-about .ab-sec + .ab-sec {
  border-top: 1px solid var(--ab-line-soft);
  padding-top: clamp(32px, 5vw, 56px);
}
.page-about .ab-sec__kicker {
  margin: 0 0 12px;
  font-size: 12px;
  letter-spacing: .18em;
  color: var(--brick);
}
.page-about .ab-sec__title {
  margin: 0 0 22px;
  max-width: 20ch;
  font-family: var(--font-title);
  font-weight: 700;
  font-size: clamp(26px, 3.6vw, 40px);
  line-height: 1.26;
  letter-spacing: -.01em;
  color: var(--deep);
}
.page-about .ab-sec p {
  margin: 0 0 18px;
  max-width: 40em;
  color: #2b2f36;
}
.page-about .ab-sec p:last-of-type { margin-bottom: 0; }

/* ---------- 分区卡 ---------- */
.page-about .ab-zones {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  display: grid;
  gap: 14px;
}
.page-about .ab-zone {
  position: relative;
  background: var(--white);
  border: var(--border);
  border-left: 4px solid var(--zone-color, var(--navy));
  border-radius: var(--radius-lg);
  padding: 18px 20px 18px 22px;
  overflow: hidden;
}
.page-about .ab-zone::after {
  content: "";
  position: absolute;
  right: -18px;
  top: -18px;
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: var(--zone-color, var(--navy));
  opacity: .06;
}
.page-about .ab-zone__num {
  display: block;
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--zone-color, var(--brick));
  margin-bottom: 6px;
}
.page-about .ab-zone__name {
  margin: 0 0 8px;
  font-family: var(--font-title);
  font-size: 19px;
  font-weight: 700;
  color: var(--deep);
}
.page-about .ab-zone__desc {
  margin: 0;
  font-size: 16px;
  line-height: 1.8;
  max-width: none;
  color: #3a4048;
}

/* ---------- 横向主题带 ---------- */
.page-about .ab-band {
  background: var(--paper-old);
  border-left: 5px solid var(--brick);
  border-radius: var(--radius-lg);
  padding: clamp(22px, 3vw, 34px);
  margin: 0 0 clamp(40px, 6vw, 68px);
}
.page-about .ab-band__label {
  margin: 0 0 18px;
  font-size: 12px;
  letter-spacing: .18em;
  color: var(--brick);
}
.page-about .ab-band__grid {
  display: grid;
  gap: 24px;
}
.page-about .ab-band__stats {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 18px;
}
.page-about .ab-band__stats li {
  border-top: 1px solid rgba(14, 36, 57, .16);
  padding-top: 10px;
}
.page-about .ab-band__num {
  display: block;
  font-size: 30px;
  line-height: 1.2;
  font-weight: 700;
  color: var(--navy);
}
.page-about .ab-band__cap {
  display: block;
  font-size: 15px;
  line-height: 1.75;
  color: #3a4048;
}
.page-about .ab-band--dark {
  background: var(--navy);
  border-left-color: var(--brass);
}
.page-about .ab-band--dark .ab-band__label { color: var(--brass); }
.page-about .ab-band--dark .ab-band__stats li { border-top-color: rgba(244, 239, 230, .22); }
.page-about .ab-band--dark .ab-band__num { color: var(--white); }
.page-about .ab-band--dark .ab-band__cap { color: rgba(244, 239, 230, .82); }

.page-about .ab-chart-wrap { margin: 0; }
.page-about .ab-chart {
  display: block;
  width: 100%;
  height: auto;
  max-width: 420px;
}
.page-about .ab-chart__axis { stroke: rgba(78, 96, 112, .4); stroke-width: 1; }
.page-about .ab-chart__bar { fill: var(--navy); }
.page-about .ab-chart__bar--last { fill: var(--brick); }
.page-about .ab-chart__tick {
  fill: var(--mist);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .08em;
}
.page-about .ab-chart__cap {
  margin: 10px 0 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--mist);
}

/* ---------- 两个时间戳 ---------- */
.page-about .ab-stamps {
  display: grid;
  gap: 14px;
}
.page-about .ab-stamp {
  background: var(--white);
  border: var(--border);
  border-left: 4px solid var(--navy);
  border-radius: var(--radius);
  padding: 14px 16px;
}
.page-about .ab-stamp--brass { border-left-color: var(--brass); }
.page-about .ab-stamp__key {
  margin: 0 0 6px;
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--brick);
}
.page-about .ab-stamp__val {
  margin: 0;
  font-size: 16px;
  line-height: 1.8;
  color: #333941;
}

/* ---------- 标签墙 ---------- */
.page-about .ab-tagwall {
  margin: 26px 0 6px;
}
.page-about .ab-tagwall .tag-list {
  padding: 6px 0;
}

/* ---------- 收尾 ---------- */
.page-about .ab-cta {
  margin-top: clamp(48px, 7vw, 96px);
  background: var(--deep);
  color: var(--paper);
  padding: clamp(36px, 6vw, 68px) 0;
}
.page-about .ab-cta__grid {
  display: grid;
  gap: 26px;
}
.page-about .ab-cta__kicker {
  margin: 0 0 14px;
  font-size: 12px;
  letter-spacing: .18em;
  color: var(--brass);
}
.page-about .ab-cta__title {
  margin: 0 0 16px;
  font-family: var(--font-title);
  font-weight: 700;
  font-size: clamp(24px, 3.2vw, 34px);
  line-height: 1.3;
  color: var(--white);
}
.page-about .ab-cta__text {
  margin: 0;
  max-width: 34em;
  font-size: 17px;
  line-height: 1.85;
  color: rgba(244, 239, 230, .84);
}
.page-about .ab-cta__btns { align-content: start; }

/* ---------- 桌面 ---------- */
@media (min-width: 700px) {
  .page-about .ab-hero__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: clamp(32px, 5vw, 72px);
    align-items: end;
  }
  .page-about .ab-zones {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 16px;
  }
  .page-about .ab-band__grid {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
    align-items: center;
    gap: 32px;
  }
  .page-about .ab-band__stats {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .ab-band__stats--three {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .page-about .ab-stamps { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .page-about .ab-cta__grid {
    grid-template-columns: minmax(0, 6fr) minmax(0, 5fr);
    gap: 40px;
    align-items: center;
  }
  .page-about .ab-figure--4x3 { margin-top: 32px; }
}

@media (min-width: 1000px) {
  .page-about .ab-body__grid {
    grid-template-columns: 190px minmax(0, 1fr);
    gap: clamp(40px, 6vw, 84px);
    align-items: start;
  }
  .page-about .ab-rail {
    position: sticky;
    top: 108px;
    padding-left: 22px;
  }
  .page-about .ab-band {
    margin-right: -22px;
  }
  .page-about .ab-sec p { font-size: 18px; }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-tick__pop,
  .page-about .ab-tick__link,
  .page-about .ab-tick__link::before {
    transition: none;
  }
}
</main>