.page-about {
  --about-rule-dark: rgba(124, 136, 148, .34);
  --about-rule-ink: rgba(8, 10, 12, .16);
  --about-rail-top: calc(var(--bar-h) + 24px);
  background: var(--night);
  color: var(--paper);
}

/* ---------- 面包屑 ---------- */
.page-about .about-crumbs {
  padding-top: var(--step-3);
  padding-bottom: var(--step-2);
}
.page-about .about-crumbs .crumbs {
  font-size: 13px;
  letter-spacing: .04em;
}
.page-about .about-crumbs .crumbs a {
  color: var(--paper-56);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  padding-bottom: 1px;
  transition: color .16s var(--ease), border-color .16s var(--ease);
}
.page-about .about-crumbs .crumbs a:hover {
  color: var(--lime);
  border-bottom-color: var(--lime);
}
.page-about .about-crumbs .crumbs [aria-current="page"] {
  color: var(--lime);
}
.page-about .about-crumbs .crumbs__sep {
  color: var(--lead);
  margin: 0 8px;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding-bottom: var(--step-5);
}
.page-about .about-hero::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1px;
  background: linear-gradient(90deg, var(--lime) 0 14%, var(--about-rule-dark) 14% 100%);
}
.page-about .about-hero__grid {
  display: grid;
  gap: var(--step-4);
}
.page-about .about-hero__text .eyebrow {
  color: var(--lime);
  font-size: 12px;
  letter-spacing: .14em;
  margin: 0 0 var(--step-3);
}
.page-about .about-hero h1 {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(30px, 6.2vw, 62px);
  line-height: 1.06;
  letter-spacing: -.025em;
  color: var(--paper);
  margin: 0 0 var(--step-3);
  max-width: 15em;
}
.page-about .about-hero .lead {
  font-size: clamp(16px, 1.9vw, 20px);
  line-height: 1.78;
  color: var(--paper-72);
  max-width: 30em;
  margin: 0;
}
.page-about .about-hero__fig {
  border-color: var(--about-rule-dark);
}

/* 图片比例容器 */
.page-about .about-shot {
  position: relative;
  margin: 0;
  overflow: hidden;
  background: var(--steel);
  border: 1px solid var(--about-rule-dark);
  box-shadow: var(--shadow-1);
}
.page-about .about-shot--3x2 { padding-bottom: 66.667%; }
.page-about .about-shot--16x9 { padding-bottom: 56.25%; }
.page-about .about-shot--10x7 { padding-bottom: 70%; }
.page-about .about-shot img {
  position: absolute;
  inset: 0;
  display: block;
  width: 100%;
  height: 100%;
  max-width: 100%;
  object-fit: cover;
  object-position: center;
}

/* 首屏数据条 */
.page-about .about-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: var(--step-5) 0 0;
  background: var(--about-rule-dark);
  border: 1px solid var(--about-rule-dark);
}
.page-about .about-facts__cell {
  background: var(--night);
  padding: var(--step-2);
}
.page-about .about-facts dt {
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--lead);
  margin: 0 0 8px;
}
.page-about .about-facts dd {
  margin: 0;
  font-size: clamp(18px, 2.4vw, 22px);
  font-weight: 700;
  color: var(--lime);
  letter-spacing: -.01em;
}

/* ---------- 正文区 ---------- */
.page-about .about-body {
  background: var(--paper);
  color: var(--ink);
}
.page-about .about-body__grid {
  padding-top: var(--step-5);
  padding-bottom: var(--step-6);
  display: grid;
  gap: var(--step-5);
}

/* ---------- 章节目录 ---------- */
.page-about .about-rail {
  min-width: 0;
}
.page-about .about-toc {
  border-top: 2px solid var(--ink);
  padding-top: var(--step-2);
}
.page-about .about-toc .toc__title {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--lead);
  margin: 0 0 var(--step-2);
}
.page-about .about-toc__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0;
}
.page-about .about-toc__list a {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 8px 8px 8px 10px;
  border-left: 2px solid transparent;
  color: var(--ink-72);
  text-decoration: none;
  font-size: 15px;
  line-height: 1.4;
  transition: color .16s var(--ease), border-color .16s var(--ease);
}
.page-about .about-toc__list a .mono {
  flex: 0 0 22px;
  font-size: 12px;
  color: var(--lead);
  letter-spacing: .06em;
}
.page-about .about-toc__list a:hover {
  color: var(--grass-mid);
}
.page-about .about-toc__list a[aria-current]:not([aria-current="false"]) {
  border-left-color: var(--lime);
  color: var(--ink);
  font-weight: 700;
}
.page-about .about-toc__list a[aria-current]:not([aria-current="false"]) .mono {
  color: var(--grass-mid);
}

@media (max-width: 959px) {
  .page-about .about-toc__list {
    display: flex;
    gap: var(--step-3);
    overflow-x: auto;
    padding-bottom: 8px;
    scrollbar-width: thin;
    -webkit-overflow-scrolling: touch;
  }
  .page-about .about-toc__list li { flex: 0 0 auto; }
  .page-about .about-toc__list a {
    border-left: 0;
    border-bottom: 2px solid transparent;
    padding: 8px 2px;
    white-space: nowrap;
  }
  .page-about .about-toc__list a[aria-current]:not([aria-current="false"]) {
    border-left-color: transparent;
    border-bottom-color: var(--lime);
  }
}

/* ---------- 章节基础 ---------- */
.page-about .about-main {
  min-width: 0;
}
.page-about .about-chapter {
  padding: var(--step-5) 0;
  border-top: 1px solid var(--about-rule-ink);
  scroll-margin-top: var(--about-rail-top);
}
.page-about .about-chapter:first-child {
  border-top: 0;
  padding-top: 0;
}
.page-about .about-chapter__num {
  display: block;
  font-size: clamp(28px, 3.6vw, 44px);
  line-height: 1;
  font-weight: 700;
  letter-spacing: -.04em;
  color: var(--grass-mid);
  margin: 0 0 10px;
}
.page-about .about-chapter h2 {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(23px, 3.2vw, 36px);
  line-height: 1.18;
  letter-spacing: -.02em;
  color: var(--ink);
  margin: 0 0 var(--step-3);
  max-width: 18em;
}
.page-about .about-chapter > p {
  max-width: 36em;
  margin: 0 0 var(--step-3);
  font-size: 16px;
  line-height: 1.85;
  color: var(--ink-72);
}
.page-about .about-fig {
  margin: var(--step-4) 0;
  border-color: var(--ink);
}

/* ---------- 原则卡片 ---------- */
.page-about .about-principles {
  list-style: none;
  margin: var(--step-4) 0 0;
  padding: 0;
  display: grid;
  gap: var(--step-3);
}
.page-about .about-slip {
  display: flex;
  flex-direction: column;
  background: var(--grass);
  border: 1px solid rgba(242, 239, 230, .24);
  box-shadow: var(--shadow-1);
  padding: var(--step-3);
  color: var(--paper);
}
.page-about .about-slip__num {
  display: block;
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--lime);
  margin: 0 0 12px;
}
.page-about .about-slip h3 {
  font-family: var(--font-display);
  font-size: 20px;
  line-height: 1.3;
  letter-spacing: -.01em;
  color: var(--paper);
  margin: 0 0 12px;
}
.page-about .about-slip > p {
  font-size: 15px;
  line-height: 1.76;
  color: var(--paper-72);
  margin: 0 0 var(--step-2);
}
.page-about .about-slip__more {
  margin-top: auto;
  border-top: 1px dashed rgba(242, 239, 230, .32);
  padding-top: 12px;
}
.page-about .about-slip__more > summary {
  list-style: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--lime);
}
.page-about .about-slip__more > summary::-webkit-details-marker { display: none; }
.page-about .about-slip__more > summary::after {
  content: "+";
  font-size: 16px;
  line-height: 1;
  color: var(--lime);
}
.page-about .about-slip__more[open] > summary::after { content: "−"; }
.page-about .about-slip__more > p {
  margin: 12px 0 0;
  font-size: 14px;
  line-height: 1.72;
  color: var(--paper-72);
}

/* ---------- 时间线 ---------- */
.page-about .about-ruler {
  list-style: none;
  margin: var(--step-4) 0 0;
  padding: 0 0 var(--step-2);
  display: flex;
  max-width: 100%;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  border-top: 2px solid var(--ink);
  scrollbar-width: thin;
  -webkit-overflow-scrolling: touch;
}
.page-about .about-ruler__item {
  flex: 1 0 132px;
  min-width: 0;
  scroll-snap-align: start;
}
.page-about .about-era {
  border-left: 1px solid var(--about-rule-ink);
  height: 100%;
}
.page-about .about-era > summary {
  position: relative;
  list-style: none;
  cursor: pointer;
  padding: 16px 12px 10px 14px;
  display: block;
}
.page-about .about-era > summary::-webkit-details-marker { display: none; }
.page-about .about-era > summary::before {
  content: "";
  position: absolute;
  left: -5px;
  top: 18px;
  width: 9px;
  height: 9px;
  background: var(--paper);
  border: 2px solid var(--ink);
}
.page-about .about-era[open] > summary::before {
  background: var(--lime);
  border-color: var(--grass-mid);
}
.page-about .about-era__year {
  display: block;
  font-size: 22px;
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -.02em;
  color: var(--ink);
}
.page-about .about-era[open] .about-era__year {
  color: var(--grass-mid);
}
.page-about .about-era__label {
  display: block;
  margin-top: 4px;
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--lead);
}
.page-about .about-era > p {
  margin: 0;
  padding: 0 12px 16px 14px;
  font-size: 14px;
  line-height: 1.74;
  color: var(--ink-72);
}

/* ---------- 表格与词条 ---------- */
.page-about .about-tablewrap {
  margin: var(--step-4) 0 var(--step-4);
  overflow-x: auto;
  border: 1px solid var(--ink);
  -webkit-overflow-scrolling: touch;
}
.page-about .about-tablewrap .about-gran {
  margin: 0;
  min-width: 560px;
  width: 100%;
}
.page-about .about-gloss {
  margin: var(--step-4) 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--about-rule-ink);
  border-top: 1px solid var(--ink);
  border-bottom: 1px solid var(--ink);
}
.page-about .about-gloss__row {
  background: var(--paper);
  padding: var(--step-2);
}
.page-about .about-gloss dt {
  font-weight: 700;
  font-size: 15px;
  color: var(--ink);
  margin: 0 0 6px;
}
.page-about .about-gloss dd {
  margin: 0;
  font-size: 14px;
  line-height: 1.72;
  color: var(--ink-72);
}

/* ---------- 编辑与校对 ---------- */
.page-about .about-roles {
  list-style: none;
  margin: var(--step-4) 0 0;
  padding: 0;
  display: grid;
  gap: var(--step-2);
}
.page-about .about-roles__item {
  background: var(--paper);
  border: 1px solid var(--ink);
  padding: var(--step-3);
}
.page-about .about-roles__num {
  display: block;
  font-size: clamp(34px, 5vw, 50px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.05em;
  color: var(--grass);
  margin: 0 0 10px;
}
.page-about .about-roles__unit {
  font-size: .42em;
  color: var(--grass-mid);
  margin-left: 4px;
  letter-spacing: 0;
}
.page-about .about-roles__item h3 {
  font-size: 17px;
  letter-spacing: -.01em;
  color: var(--ink);
  margin: 0 0 8px;
}
.page-about .about-roles__item p {
  margin: 0;
  font-size: 14px;
  line-height: 1.72;
  color: var(--ink-72);
}
.page-about .about-response {
  margin-top: var(--step-4);
  padding: var(--step-2) 0 var(--step-2) var(--step-3);
  border-left: 3px solid var(--brick);
}
.page-about .about-response h3 {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--brick);
  margin: 0 0 12px;
}
.page-about .about-response ol {
  margin: 0;
  padding-left: 1.1em;
  display: grid;
  gap: 10px;
}
.page-about .about-response li {
  font-size: 15px;
  line-height: 1.74;
  color: var(--ink-72);
}
.page-about .about-response .mono {
  color: var(--ink);
  font-weight: 700;
}

/* ---------- 选材标准 ---------- */
.page-about .about-picks {
  list-style: none;
  counter-reset: pick;
  margin: var(--step-4) 0 0;
  padding: 0;
  display: grid;
  gap: var(--step-4);
}
.page-about .about-picks li {
  counter-increment: pick;
  border-top: 1px dashed var(--about-rule-ink);
  padding-top: var(--step-2);
}
.page-about .about-picks li::before {
  content: counter(pick, decimal-leading-zero);
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--grass-mid);
  margin-bottom: 10px;
}
.page-about .about-picks h3 {
  font-family: var(--font-display);
  font-size: clamp(19px, 2.2vw, 24px);
  letter-spacing: -.015em;
  color: var(--ink);
  margin: 0 0 10px;
}
.page-about .about-picks p {
  margin: 0;
  max-width: 34em;
  font-size: 15px;
  line-height: 1.82;
  color: var(--ink-72);
}

/* ---------- 继续阅读 ---------- */
.page-about .about-links {
  list-style: none;
  margin: var(--step-4) 0 0;
  padding: 0;
  border-top: 1px solid var(--ink);
}
.page-about .about-links a {
  display: grid;
  grid-template-columns: 40px minmax(0, 1fr);
  gap: 2px var(--step-2);
  padding: var(--step-2) 4px;
  border-bottom: 1px solid var(--about-rule-ink);
  text-decoration: none;
  color: var(--ink);
  transition: background .16s var(--ease), color .16s var(--ease);
}
.page-about .about-links__k {
  grid-row: span 2;
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--grass-mid);
  padding-top: 3px;
}
.page-about .about-links strong {
  font-size: 16px;
  letter-spacing: -.01em;
  color: inherit;
}
.page-about .about-links a > span:last-child {
  font-size: 14px;
  line-height: 1.65;
  color: var(--ink-56);
}
.page-about .about-links a:hover,
.page-about .about-links a:focus-visible {
  background: var(--grass);
  color: var(--paper);
}
.page-about .about-links a:hover .about-links__k,
.page-about .about-links a:focus-visible .about-links__k {
  color: var(--lime);
}
.page-about .about-links a:hover > span:last-child,
.page-about .about-links a:focus-visible > span:last-child {
  color: var(--paper-72);
}

/* ---------- 页尾动作 ---------- */
.page-about .about-topline {
  margin-top: var(--step-5);
  padding-top: var(--step-3);
  border-top: 2px solid var(--ink);
}
.page-about .about-jump {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--ink);
  text-decoration: none;
  border-bottom: 1px solid var(--ink);
  padding-bottom: 2px;
  transition: color .16s var(--ease), border-color .16s var(--ease);
}
.page-about .about-jump:hover,
.page-about .about-jump:focus-visible {
  color: var(--grass-mid);
  border-bottom-color: var(--grass-mid);
}

/* ---------- 响应式栅格 ---------- */
@media (min-width: 700px) {
  .page-about .about-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .about-principles {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: var(--step-2);
  }
  .page-about .about-roles {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .about-gloss {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: var(--step-5);
    align-items: end;
  }
}

@media (min-width: 960px) {
  .page-about .about-body__grid {
    grid-template-columns: repeat(12, minmax(0, 1fr));
    column-gap: var(--step-3);
    row-gap: 0;
    align-items: start;
  }
  .page-about .about-rail {
    grid-column: 1 / span 3;
    position: sticky;
    top: var(--about-rail-top);
    align-self: start;
    max-height: calc(100vh - var(--bar-h) - 48px);
    overflow-y: auto;
    scrollbar-width: thin;
  }
  .page-about .about-main {
    grid-column: 5 / span 8;
  }
  .page-about .about-chapter > p {
    font-size: 17px;
  }
  .page-about .about-chapter {
    padding: var(--step-6) 0;
  }
  .page-about .about-chapter:first-child {
    padding-top: 0;
  }
}

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