.page-about {
  background: var(--c-cream);
  color: var(--c-brown);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.7;
  overflow-x: hidden;
}

.page-about .mono {
  font-family: var(--font-mono);
  letter-spacing: .08em;
}

/* ---------- 首屏 ---------- */

.page-about .ledger-hero {
  position: relative;
  background: var(--c-night);
  color: var(--c-paper);
  padding: clamp(104px, 17vw, 186px) 0 clamp(44px, 6vw, 72px);
  overflow: hidden;
  isolation: isolate;
}

.page-about .ledger-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(244, 232, 208, .07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(244, 232, 208, .07) 1px, transparent 1px);
  background-size: 36px 36px;
  z-index: -1;
  pointer-events: none;
}

.page-about .ledger-hero::after {
  content: "";
  position: absolute;
  right: -18%;
  top: 12%;
  width: 58vw;
  height: 58vw;
  max-width: 560px;
  max-height: 560px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(255, 107, 53, .20), transparent 68%);
  z-index: -1;
  pointer-events: none;
}

.page-about .ledger-hero .breadcrumb {
  color: var(--paper-dim);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
}

.page-about .ledger-hero .breadcrumb a {
  color: var(--c-paper);
  text-decoration: none;
  border-bottom: 1px solid rgba(244, 232, 208, .38);
  transition: color .2s var(--ease), border-color .2s var(--ease);
}

.page-about .ledger-hero .breadcrumb a:hover,
.page-about .ledger-hero .breadcrumb a:focus-visible {
  color: var(--c-signal);
  border-color: var(--c-signal);
}

.page-about .ledger-hero__kicker {
  margin: clamp(22px, 3vw, 34px) 0 12px;
  font-size: 12px;
  letter-spacing: .24em;
  text-transform: uppercase;
  color: var(--c-signal);
}

.page-about .ledger-hero__title {
  margin: 0 0 20px;
  font-family: var(--font-display);
  font-weight: 300;
  font-size: clamp(52px, 15vw, 128px);
  line-height: .92;
  letter-spacing: -.02em;
  color: var(--c-paper);
}

.page-about .ledger-hero__lede {
  max-width: 60ch;
  margin: 0 0 clamp(30px, 4.4vw, 46px);
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.75;
  color: var(--paper-soft);
}

.page-about .ledger-hero__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin: 0;
  padding: 0;
  border-top: 2px solid var(--line-night);
}

.page-about .ledger-hero__facts > div {
  padding: 15px 12px 15px 0;
  border-bottom: 2px solid var(--line-night);
}

.page-about .ledger-hero__facts dt {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--c-steel);
  margin-bottom: 5px;
}

.page-about .ledger-hero__facts dd {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(26px, 5vw, 34px);
  line-height: 1;
  color: var(--c-paper);
}

/* ---------- 章节骨架 ---------- */

.page-about .about-chapter {
  padding: clamp(52px, 8.5vw, 108px) 0;
  position: relative;
}

.page-about .about-chapter--paper {
  background: var(--c-paper);
}

.page-about .about-chapter--night {
  background: var(--c-night);
  color: var(--c-paper);
}

.page-about .about-chapter--deep {
  background: var(--c-deep);
  color: var(--c-paper);
}

.page-about .chapter-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px 20px;
  border-top: 3px solid currentColor;
  padding-top: 16px;
  margin-bottom: clamp(22px, 3.4vw, 38px);
}

.page-about .chapter-head__index {
  font-family: var(--font-mono);
  font-size: clamp(26px, 5.4vw, 42px);
  font-weight: 500;
  line-height: 1;
  color: var(--c-rust);
  text-decoration: none;
  transition: color .2s var(--ease), transform .2s var(--ease);
}

.page-about .about-chapter--night .chapter-head__index,
.page-about .about-chapter--deep .chapter-head__index {
  color: var(--c-signal);
}

.page-about .chapter-head__index:focus-visible {
  outline: 3px solid var(--c-signal);
  outline-offset: 3px;
}

.page-about .chapter-head__title {
  flex: 1 1 12ch;
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(24px, 4.8vw, 40px);
  line-height: 1.1;
  letter-spacing: -.01em;
}

.page-about .chapter-head__note {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--ink-soft);
}

.page-about .about-chapter--night .chapter-head__note,
.page-about .about-chapter--deep .chapter-head__note {
  color: var(--paper-dim);
}

.page-about .lede {
  max-width: 66ch;
  margin: 0 0 clamp(28px, 4vw, 46px);
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.8;
  color: var(--ink-soft);
}

.page-about .about-chapter--night .lede,
.page-about .about-chapter--deep .lede {
  color: var(--paper-soft);
}

/* ---------- 图片 ---------- */

.page-about .about-figure {
  margin: clamp(30px, 4.6vw, 52px) 0 0;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border: 2px solid var(--c-brown);
  box-shadow: var(--shadow-hard);
  background: var(--c-deep);
}

.page-about .about-chapter--night .about-figure img,
.page-about .about-chapter--deep .about-figure img {
  border-color: var(--c-shadow);
  box-shadow: 6px 6px 0 rgba(6, 24, 29, .9);
}

.page-about .about-figure--wide img {
  opacity: .62;
}

.page-about .about-figure figcaption {
  margin-top: 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--ink-soft);
  border-left: 4px solid var(--c-rust);
  padding-left: 10px;
}

.page-about .about-chapter--night .about-figure figcaption,
.page-about .about-chapter--deep .about-figure figcaption {
  color: var(--paper-dim);
}

/* ---------- 沿革时间轴 ---------- */

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

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 15px;
  top: 12px;
  bottom: 30px;
  width: 3px;
  background: linear-gradient(180deg, var(--c-rust), var(--c-signal) 46%, var(--c-proof));
}

.page-about .timeline__node {
  position: relative;
  padding: 0 0 clamp(26px, 3.6vw, 40px) 48px;
}

.page-about .timeline__node::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 9px;
  width: 21px;
  height: 21px;
  border-radius: 50%;
  background: var(--c-cream);
  border: 3px solid var(--c-brown);
  transition: background .22s var(--ease), border-color .22s var(--ease), transform .22s var(--ease);
  z-index: 1;
}

.page-about .timeline__node:hover::before,
.page-about .timeline__node:focus-within::before {
  background: var(--c-signal);
  border-color: var(--c-rust);
  transform: scale(1.14);
}

.page-about .timeline__body {
  transition: transform .22s var(--ease);
}

.page-about .timeline__node:hover .timeline__body,
.page-about .timeline__node:focus-within .timeline__body {
  transform: translateX(5px);
}

.page-about .timeline__mark {
  display: inline-block;
  margin-bottom: 10px;
  padding: 3px 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  background: var(--c-brown);
  color: var(--c-cream);
}

.page-about .timeline__title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(20px, 3.2vw, 27px);
  line-height: 1.2;
}

.page-about .timeline__body p {
  margin: 0 0 8px;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-soft);
}

.page-about .timeline__detail {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--c-rust);
}

/* ---------- 内容口径 ---------- */

.page-about .rule-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 20px;
}

.page-about .rule-list__item {
  border-left: 5px solid var(--c-rust);
  padding: 2px 0 2px 18px;
}

.page-about .rule-list__key {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(20px, 3.2vw, 26px);
  line-height: 1.2;
  color: var(--c-brown);
}

.page-about .rule-list__item p {
  margin: 0;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-soft);
}

.page-about .creed {
  margin-top: clamp(30px, 4.4vw, 48px);
  background: var(--c-night);
  color: var(--c-paper);
  border: 2px solid var(--c-brown);
  border-left: 8px solid var(--c-signal);
  box-shadow: var(--shadow-hard);
  padding: clamp(22px, 3.4vw, 34px);
}

.page-about .creed__line {
  margin: 0 0 12px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(22px, 4.4vw, 36px);
  line-height: 1.2;
  letter-spacing: -.01em;
}

.page-about .creed__note {
  margin: 0;
  max-width: 58ch;
  font-size: 14px;
  line-height: 1.8;
  color: var(--paper-soft);
}

/* ---------- 四类内容 ---------- */

.page-about .cat-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
}

.page-about .cat-card {
  background: var(--c-paper);
  color: var(--c-brown);
  border: 2px solid var(--c-brown);
  box-shadow: 6px 6px 0 var(--c-shadow);
  padding: 22px 22px 24px;
  transition: transform .22s var(--ease), box-shadow .22s var(--ease);
}

.page-about .cat-card:hover,
.page-about .cat-card:focus-within {
  transform: translate(-3px, -3px);
  box-shadow: 10px 10px 0 var(--c-signal);
}

.page-about .cat-card__no {
  display: block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .18em;
  color: var(--c-rust);
}

.page-about .cat-card__title {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(20px, 3vw, 25px);
  line-height: 1.2;
}

.page-about .cat-card__desc {
  margin: 0 0 14px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-soft);
}

.page-about .cat-card__role {
  margin: 0;
  padding-top: 12px;
  border-top: 2px solid var(--line-ink);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--c-deep);
}

/* ---------- 校验流程 ---------- */

.page-about .check-flow {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

.page-about .check-flow__item {
  position: relative;
  background: var(--c-paper);
  border: 2px solid var(--c-brown);
  border-left: 6px solid var(--c-rust);
  padding: 20px 22px 22px;
  transition: transform .22s var(--ease), box-shadow .22s var(--ease);
}

.page-about .check-flow__item--pass {
  border-left-color: var(--c-proof);
}

.page-about .check-flow__item:hover,
.page-about .check-flow__item:focus-within {
  transform: translateY(-3px);
  box-shadow: var(--shadow-hard);
}

.page-about .check-flow__step {
  display: block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--c-steel);
}

.page-about .check-flow__title {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(19px, 3vw, 24px);
  line-height: 1.2;
}

.page-about .check-flow__item p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-soft);
}

.page-about .crew {
  margin-top: clamp(30px, 4.4vw, 48px);
  display: flex;
  flex-wrap: wrap;
  align-items: flex-start;
  gap: 20px 28px;
  border-top: 3px solid var(--c-brown);
  border-bottom: 3px solid var(--c-brown);
  padding: clamp(22px, 3.4vw, 34px) 0;
}

.page-about .crew__num {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(46px, 11vw, 86px);
  line-height: .9;
  color: var(--c-rust);
  letter-spacing: -.02em;
}

.page-about .crew__body {
  flex: 1 1 22ch;
}

.page-about .crew__title {
  margin: 0 0 12px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(18px, 2.6vw, 22px);
}

.page-about .crew__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 8px;
}

.page-about .crew__list li {
  font-size: 15px;
  line-height: 1.7;
  color: var(--ink-soft);
  padding-left: 14px;
  border-left: 3px solid var(--line-ink);
}

.page-about .crew__list .mono {
  display: inline-block;
  min-width: 6.5em;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--c-deep);
}

/* ---------- 省域提示 ---------- */

.page-about .jx-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(24px, 3.6vw, 44px);
}

.page-about .jx-copy p {
  margin: 0 0 16px;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.85;
  color: var(--paper-soft);
}

.page-about .jx-points {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .jx-points li {
  border-left: 4px solid var(--c-signal);
  padding: 2px 0 2px 14px;
}

.page-about .jx-points__k {
  display: block;
  margin-bottom: 4px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--c-signal);
}

.page-about .jx-points p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--paper-soft);
}

/* ---------- 后续入口 ---------- */

.page-about .next-links {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  border-top: 2px solid var(--line-ink);
}

.page-about .next-links__item {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 4px 18px;
  padding: 18px 0;
  border-bottom: 2px solid var(--line-ink);
}

.page-about .next-links__link {
  flex: 0 0 auto;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(18px, 2.6vw, 22px);
  color: var(--c-brown);
  text-decoration: none;
  border-bottom: 3px solid var(--c-rust);
  transition: color .2s var(--ease), border-color .2s var(--ease);
}

.page-about .next-links__link:hover,
.page-about .next-links__link:focus-visible {
  color: var(--c-rust);
  border-color: var(--c-signal);
}

.page-about .next-links__link:focus-visible {
  outline: 3px solid var(--c-signal);
  outline-offset: 4px;
}

.page-about .next-links__desc {
  flex: 1 1 20ch;
  font-size: 14px;
  line-height: 1.7;
  color: var(--ink-soft);
}

/* ---------- 焦点可见性 ---------- */

.page-about a:focus-visible {
  outline: 3px solid var(--c-signal);
  outline-offset: 3px;
}

/* ---------- 响应式 ---------- */

@media (min-width: 720px) {
  .page-about .ledger-hero__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .ledger-hero__facts > div {
    padding-right: 20px;
  }

  .page-about .rule-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 24px;
  }

  .page-about .check-flow {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .jx-grid {
    grid-template-columns: 1.05fr 1fr;
    align-items: start;
  }
}

@media (min-width: 900px) {
  .page-about .cat-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .next-links__item {
    padding: 20px 0;
  }
}

@media (min-width: 1100px) {
  .page-about .cat-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .timeline__node {
    padding-left: 62px;
  }

  .page-about .timeline::before {
    left: 19px;
  }

  .page-about .timeline__node::before {
    left: 10px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about * {
    transition-duration: .01ms !important;
    animation-duration: .01ms !important;
  }
}