.page-about {
  --about-rail-w: 200px;
  display: block;
  padding-top: clamp(16px, 2.4vw, 28px);
  padding-bottom: clamp(0px, 1vw, 12px);
  color: var(--paper);
  background-color: var(--ink);
  background-image: linear-gradient(
    180deg,
    var(--maroon) 0%,
    rgba(74, 12, 22, .5) 12%,
    rgba(21, 10, 14, .92) 34%,
    var(--ink) 64%
  );
  background-repeat: no-repeat;
  overflow-x: hidden;
}

.page-about .about-head {
  padding-bottom: clamp(8px, 1.4vw, 16px);
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  padding: clamp(16px, 2.6vw, 36px) 0 clamp(28px, 4.4vw, 58px);
}

.page-about .about-eyebrow {
  margin: 0 0 12px;
  font-family: var(--font-body);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: .18em;
  color: var(--gold-hi);
}

.page-about .about-hero h1 {
  margin: 0;
  max-width: 21ch;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(27px, 4.4vw, 52px);
  line-height: 1.18;
  letter-spacing: -.01em;
  color: var(--paper);
}

.page-about .about-lead {
  margin: clamp(14px, 2vw, 22px) 0 0;
  max-width: 66ch;
  font-size: clamp(15px, 1.38vw, 17.5px);
  line-height: 1.85;
  color: rgba(243, 231, 214, .86);
}

.page-about .about-span {
  display: flex;
  align-items: center;
  gap: clamp(10px, 1.8vw, 26px);
  margin: clamp(22px, 3.2vw, 38px) 0 0;
  font-family: var(--font-data);
  font-weight: 700;
  font-size: clamp(38px, 8.6vw, 110px);
  line-height: .9;
  letter-spacing: -.03em;
  font-variant-numeric: tabular-nums;
}

.page-about .span-from {
  color: var(--gold);
  opacity: .8;
  flex: 0 0 auto;
}

.page-about .span-to {
  color: var(--gold-hi);
  flex: 0 0 auto;
}

.page-about .span-line {
  flex: 1 1 auto;
  min-width: 24px;
  height: 1px;
  background: linear-gradient(90deg, var(--line-strong), var(--pulse));
}

.page-about .about-stats {
  list-style: none;
  margin: clamp(24px, 3.4vw, 40px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line);
}

.page-about .about-stats li {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: clamp(13px, 1.7vw, 20px) clamp(12px, 1.6vw, 20px);
  background: rgba(14, 7, 10, .74);
}

.page-about .stat-num {
  font-family: var(--font-data);
  font-weight: 700;
  font-size: clamp(23px, 2.7vw, 33px);
  line-height: 1;
  color: var(--gold-hi);
  font-variant-numeric: tabular-nums;
}

.page-about .stat-label {
  font-size: 12.5px;
  line-height: 1.55;
  letter-spacing: .04em;
  color: var(--mist);
}

/* ---------- 主体：年份刻度 + 时间线 ---------- */

.page-about .about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 3vw, 40px);
  margin-top: clamp(26px, 4vw, 50px);
}

.page-about .about-rail {
  padding-top: 14px;
  border-top: 1px solid var(--line);
}

.page-about .rail-label {
  margin: 0 0 10px;
  font-family: var(--font-body);
  font-size: 11.5px;
  font-weight: 500;
  letter-spacing: .2em;
  color: var(--gold);
}

.page-about .rail-list {
  list-style: none;
  margin: 0;
  padding: 0 0 6px;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
}

.page-about .rail-list::-webkit-scrollbar {
  display: none;
}

.page-about .rail-list li {
  flex: 0 0 auto;
}

.page-about .rail-list a {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 8px 12px;
  border: 1px solid var(--line-soft);
  text-decoration: none;
  transition: color .25s var(--ease), border-color .25s var(--ease), background-color .25s var(--ease);
}

.page-about .rail-year {
  font-family: var(--font-data);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .02em;
  color: var(--gold-hi);
  white-space: nowrap;
}

.page-about .rail-note {
  font-size: 11.5px;
  letter-spacing: .04em;
  color: var(--mist);
  white-space: nowrap;
}

.page-about .rail-list a:hover,
.page-about .rail-list a:focus-visible {
  color: var(--gold-hi);
  border-color: var(--gold);
  background: rgba(168, 20, 40, .16);
}

.page-about .rail-list a:hover .rail-note,
.page-about .rail-list a:focus-visible .rail-note {
  color: rgba(243, 231, 214, .85);
}

/* ---------- 章节 ---------- */

.page-about .about-track {
  min-width: 0;
}

.page-about .about-chapter {
  padding: clamp(22px, 3vw, 36px) 0 clamp(26px, 3.4vw, 46px);
  border-top: 1px solid var(--line);
  scroll-margin-top: calc(var(--header-h) + 24px);
}

.page-about .chapter-head {
  display: flex;
  align-items: baseline;
  gap: clamp(10px, 1.6vw, 18px);
  margin-bottom: clamp(12px, 1.7vw, 20px);
}

.page-about .chapter-index {
  flex: 0 0 auto;
  margin: 0;
  font-family: var(--font-data);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .16em;
  color: var(--gold);
}

.page-about .chapter-title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(21px, 2.9vw, 30px);
  line-height: 1.22;
  letter-spacing: -.005em;
  color: var(--paper);
}

.page-about .about-chapter:nth-of-type(2) .chapter-title {
  font-size: clamp(22px, 3.05vw, 32px);
}

.page-about .about-chapter:nth-of-type(3) .chapter-title {
  font-size: clamp(23px, 3.2vw, 34px);
}

.page-about .about-chapter:nth-of-type(4) .chapter-title {
  font-size: clamp(24px, 3.35vw, 36px);
}

.page-about .chapter-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(18px, 2.4vw, 30px);
}

.page-about .chapter-prose p {
  margin: 0 0 1em;
  font-size: clamp(15px, 1.36vw, 16.5px);
  line-height: 1.85;
  color: rgba(243, 231, 214, .85);
}

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

/* ---------- 字段框 ---------- */

.page-about .field-box {
  padding: 14px 16px 12px;
  border: 1px solid var(--line);
  border-left: 2px solid var(--gold);
  background: rgba(14, 7, 10, .62);
}

.page-about .field-box-title {
  margin: 0 0 10px;
  font-size: 11.5px;
  font-weight: 500;
  letter-spacing: .16em;
  color: var(--gold-hi);
}

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

.page-about .field-list li {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 10px;
  padding: 6px 0;
  border-bottom: 1px dashed var(--line-soft);
  font-size: 12.5px;
}

.page-about .field-list li:last-child {
  border-bottom: none;
}

.page-about .field-key {
  color: var(--mist);
  letter-spacing: .04em;
}

.page-about .field-val {
  font-family: var(--font-data);
  font-size: 12.5px;
  color: var(--paper);
  white-space: nowrap;
}

.page-about .field-list--stacked li {
  display: block;
}

.page-about .field-list--stacked .field-key {
  display: block;
  margin-bottom: 2px;
  font-size: 12.5px;
  color: var(--paper);
}

.page-about .field-list--stacked .field-val {
  display: block;
  font-family: var(--font-body);
  font-size: 12px;
  line-height: 1.6;
  color: var(--mist);
  white-space: normal;
}

.page-about .field-num-list {
  list-style: none;
  counter-reset: fn;
  margin: 0;
  padding: 0;
}

.page-about .field-num-list li {
  counter-increment: fn;
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 6px 0;
  border-bottom: 1px dashed var(--line-soft);
  font-size: 12.5px;
  color: var(--paper);
}

.page-about .field-num-list li:last-child {
  border-bottom: none;
}

.page-about .field-num-list li::before {
  content: counter(fn, decimal-leading-zero);
  font-family: var(--font-data);
  font-size: 10.5px;
  letter-spacing: .06em;
  color: var(--gold);
}

/* ---------- 图 ---------- */

.page-about .about-figure {
  margin: clamp(24px, 3.6vw, 44px) 0;
  padding: 8px;
  border: 1px solid var(--line);
  background: rgba(14, 7, 10, .58);
}

.page-about .about-figure--plated {
  box-shadow: inset 0 0 0 1px rgba(184, 137, 60, .16);
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  filter: saturate(.92) contrast(1.04);
}

.page-about .about-figure figcaption {
  padding: 10px 4px 2px;
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--mist);
}

/* ---------- 页尾引导 ---------- */

.page-about .about-next {
  margin-top: clamp(34px, 5vw, 70px);
  border-top: 1px solid var(--line-strong);
  border-bottom: 1px solid var(--line-soft);
  background: linear-gradient(120deg, rgba(74, 12, 22, .9) 0%, rgba(14, 7, 10, .25) 62%);
}

.page-about .about-next-inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(18px, 2.4vw, 30px);
  padding: clamp(28px, 4vw, 56px) 0;
}

.page-about .about-next h2 {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(22px, 2.8vw, 32px);
  line-height: 1.24;
  color: var(--paper);
}

.page-about .about-next p {
  margin: 0;
  max-width: 48ch;
  font-size: 15px;
  line-height: 1.82;
  color: rgba(243, 231, 214, .82);
}

.page-about .next-links {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
}

.page-about .next-links .link-quiet {
  font-size: 13.5px;
}

/* ---------- 响应式 ---------- */

@media (min-width: 620px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 760px) {
  .page-about .chapter-grid {
    grid-template-columns: minmax(0, 1fr) minmax(190px, 252px);
    align-items: start;
  }

  .page-about .about-next-inner {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, .85fr);
    align-items: center;
  }

  .page-about .next-links {
    justify-content: flex-end;
  }
}

@media (min-width: 1000px) {
  .page-about .about-body {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: clamp(36px, 4.5vw, 82px);
  }

  .page-about .about-rail {
    position: sticky;
    top: calc(var(--header-h) + 28px);
    align-self: start;
    padding: 0 0 0 18px;
    border-top: none;
    border-left: 1px solid var(--line);
  }

  .page-about .rail-list {
    display: block;
    overflow: visible;
    padding: 0;
  }

  .page-about .rail-list li {
    margin-bottom: 3px;
  }

  .page-about .rail-list a {
    display: block;
    padding: 9px 0;
    border: none;
    border-bottom: 1px solid var(--line-soft);
  }

  .page-about .rail-list a:hover,
  .page-about .rail-list a:focus-visible {
    background: transparent;
    padding-left: 8px;
  }

  .page-about .rail-note {
    display: block;
    margin-top: 3px;
    white-space: normal;
    line-height: 1.5;
  }

  .page-about .about-figure--mid {
    margin-right: clamp(0px, 6vw, 120px);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .rail-list a,
  .page-about .field-list li,
  .page-about .field-num-list li {
    transition: none;
  }
}