.page-about {
  --about-rail-w: 152px;
  --about-paper-line: rgba(27, 26, 23, 0.14);
  background: var(--ink);
  color: var(--text-on-ink);
  font-family: var(--font-body);
  overflow-x: hidden;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: clamp(22px, 4.4vw, 50px) 0 clamp(34px, 6vw, 76px);
  background:
    radial-gradient(115% 85% at 84% 6%, rgba(232, 181, 74, 0.18), transparent 58%),
    radial-gradient(95% 72% at 6% 94%, rgba(111, 227, 255, 0.13), transparent 62%),
    linear-gradient(158deg, var(--ink-deep) 0%, var(--ink) 46%, var(--ink-layer) 100%);
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: -18% -8%;
  background-image: repeating-linear-gradient(122deg, rgba(201, 210, 220, 0.05) 0 1px, transparent 1px 7px);
  pointer-events: none;
}

.page-about .breadcrumb {
  position: relative;
  margin: 0 0 18px;
  font-size: 13px;
  letter-spacing: 0.04em;
}

.page-about .breadcrumb a {
  color: var(--text-dim);
  text-decoration: none;
}

.page-about .breadcrumb a:hover,
.page-about .breadcrumb a:focus-visible {
  color: var(--gold);
}

.page-about .breadcrumb span[aria-current="page"] {
  color: var(--text-on-ink);
}

.page-about .about-hero__frame {
  position: relative;
  padding: clamp(22px, 4.2vw, 50px);
  border: 1px solid var(--line-gold);
  border-radius: var(--radius-organic);
  background: linear-gradient(164deg, rgba(232, 181, 74, 0.07), rgba(255, 255, 255, 0) 46%);
  box-shadow: var(--shadow-deep);
}

.page-about .about-hero__frame::after {
  content: "";
  position: absolute;
  inset: 9px;
  border: 1px dashed rgba(232, 181, 74, 0.22);
  border-radius: 16px 6px 16px 6px;
  pointer-events: none;
}

.page-about .about-hero__eyebrow {
  position: relative;
  margin: 0;
  color: var(--gold);
}

.page-about .about-hero__title {
  position: relative;
  margin: 14px 0 0;
  max-width: 22ch;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(28px, 6.4vw, 54px);
  line-height: 1.16;
  letter-spacing: 0.01em;
  color: var(--gold-light);
  text-shadow: 0 0 1px var(--gold), 0 0 28px rgba(232, 181, 74, 0.32);
}

.page-about .about-hero__lead {
  position: relative;
  margin: 18px 0 0;
  max-width: 42ch;
  font-size: 16.5px;
  line-height: 1.85;
  color: var(--text-mute);
}

.page-about .about-hero__actions {
  position: relative;
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: 26px 0 0;
}

.page-about .about-hero__stats {
  position: relative;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px 22px;
  margin: 30px 0 0;
  padding: 22px 0 0;
  border-top: 1px solid var(--line-hair);
}

.page-about .about-hero__stat dt {
  margin: 0 0 6px;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--text-dim);
}

.page-about .about-hero__stat dd {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(19px, 3vw, 24px);
  line-height: 1.2;
  letter-spacing: 0.01em;
  color: var(--gold-light);
}

@media (min-width: 760px) {
  .page-about .about-hero__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

/* ---------- 长卷主体 ---------- */
.page-about .about-chronicle {
  position: relative;
  padding: clamp(32px, 5.4vw, 78px) 0 clamp(44px, 7vw, 100px);
  background: var(--paper);
  color: var(--soot);
}

.page-about .about-chronicle__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 24px;
}

/* 移动端：横向章节胶囊 */
.page-about .about-rail {
  order: -1;
  overflow-x: auto;
  overflow-y: hidden;
  padding-bottom: 6px;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: thin;
}

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

.page-about .about-rail__item {
  flex: 0 0 auto;
}

.page-about .about-rail__link {
  display: inline-flex;
  align-items: baseline;
  gap: 6px;
  padding: 7px 13px;
  border: 1px solid var(--about-paper-line);
  border-radius: 999px;
  font-size: 13px;
  line-height: 1;
  white-space: nowrap;
  text-decoration: none;
  color: rgba(27, 26, 23, 0.72);
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease), background-color 0.2s var(--ease);
}

.page-about .about-rail__link .mono {
  font-size: 11px;
  letter-spacing: 0.06em;
  color: rgba(27, 26, 23, 0.48);
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  color: var(--ink);
  border-color: var(--gold);
  background: rgba(232, 181, 74, 0.16);
}

.page-about .about-stream {
  min-width: 0;
  max-width: var(--wrap-narrow);
}

/* 章节 */
.page-about .about-chapter {
  padding: clamp(30px, 4.6vw, 54px) 0;
  border-top: 1px dashed var(--about-paper-line);
}

.page-about .about-chapter:first-child {
  border-top: 0;
  padding-top: 0;
}

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

.page-about .about-chapter .chapter-marker {
  margin-bottom: 12px;
}

.page-about .about-chapter .chapter-marker__num {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--ink);
}

.page-about .about-chapter .chapter-marker__line {
  background: linear-gradient(90deg, rgba(27, 26, 23, 0.32), rgba(27, 26, 23, 0));
}

.page-about .about-chapter__title {
  margin: 0 0 16px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(21px, 3.6vw, 32px);
  line-height: 1.3;
  letter-spacing: 0.005em;
  color: var(--ink);
}

.page-about .about-chapter__body p {
  margin: 0 0 14px;
  max-width: 42ch;
  font-size: 16.5px;
  line-height: 1.85;
  color: var(--soot);
}

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

.page-about .about-chapter__body--after {
  margin-top: 26px;
}

.page-about .about-chapter__figure {
  margin: 24px 0 6px;
}

.page-about .about-chapter__figure .img-frame img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .about-chapter__caption {
  display: block;
  margin-top: 10px;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: rgba(27, 26, 23, 0.5);
}

/* ---------- 版本卡片带 ---------- */
.page-about .about-versions {
  display: flex;
  gap: 12px;
  margin: 22px -4px 0;
  padding: 4px 4px 16px;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: thin;
}

.page-about .about-version {
  position: relative;
  flex: 0 0 min(226px, 74vw);
  padding: 18px 16px 20px 24px;
  overflow: hidden;
  scroll-snap-align: start;
  border: 1px solid rgba(232, 181, 74, 0.38);
  border-radius: var(--radius-soft);
  background: linear-gradient(168deg, var(--ink-layer) 0%, var(--ink-deep) 100%);
  color: var(--text-on-ink);
}

.page-about .about-version::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 7px;
  background: repeating-linear-gradient(115deg, rgba(201, 210, 220, 0.72) 0 1px, rgba(201, 210, 220, 0.08) 1px 4px);
  opacity: 0.55;
}

.page-about .about-version__tag {
  display: inline-block;
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--gold);
}

.page-about .about-version__text {
  margin: 10px 0 0;
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--text-mute);
}

.page-about .about-versions__foot {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-top: 4px;
}

.page-about .about-versions__hint {
  margin: 0;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: rgba(27, 26, 23, 0.5);
}

.page-about .about-versions__more {
  border-color: rgba(27, 26, 23, 0.35);
  color: var(--ink);
}

.page-about .about-versions__more:hover,
.page-about .about-versions__more:focus-visible {
  border-color: var(--gold);
  color: var(--ink);
  background: rgba(232, 181, 74, 0.16);
}

/* ---------- 产出流程 ---------- */
.page-about .about-flow {
  display: grid;
  gap: 2px;
  margin: 20px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-flow__step {
  display: grid;
  grid-template-columns: 46px minmax(0, 1fr);
  gap: 4px 12px;
  padding: 16px 18px;
  border-left: 3px solid rgba(232, 181, 74, 0.7);
  border-radius: 0 var(--radius-soft) var(--radius-soft) 0;
  background: rgba(7, 26, 47, 0.045);
}

.page-about .about-flow__num {
  grid-row: span 2;
  font-size: 20px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: rgba(27, 26, 23, 0.32);
}

.page-about .about-flow__title {
  margin: 0;
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
}

.page-about .about-flow__text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: rgba(27, 26, 23, 0.78);
}

/* ---------- 房间阶梯 ---------- */
.page-about .about-rooms {
  display: grid;
  gap: 8px;
  margin: 20px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-rooms__item {
  padding: 13px 18px;
  border-left: 3px solid rgba(232, 181, 74, 0.6);
  border-radius: 0 var(--radius-soft) var(--radius-soft) 0;
  background: rgba(7, 26, 47, 0.05);
}

.page-about .about-rooms__item:nth-child(1) { border-left-color: rgba(232, 181, 74, 0.24); }
.page-about .about-rooms__item:nth-child(2) { border-left-color: rgba(232, 181, 74, 0.36); }
.page-about .about-rooms__item:nth-child(3) { border-left-color: rgba(232, 181, 74, 0.48); }
.page-about .about-rooms__item:nth-child(4) { border-left-color: rgba(232, 181, 74, 0.62); }
.page-about .about-rooms__item:nth-child(5) { border-left-color: rgba(232, 181, 74, 0.78); }
.page-about .about-rooms__item:nth-child(6) { border-left-color: rgba(232, 181, 74, 0.98); }

.page-about .about-rooms__name {
  margin: 0 0 4px;
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
}

.page-about .about-rooms__name .mono {
  margin-right: 8px;
  font-size: 11px;
  letter-spacing: 0.08em;
  color: rgba(27, 26, 23, 0.4);
}

.page-about .about-rooms__text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.72;
  color: rgba(27, 26, 23, 0.76);
}

/* ---------- 关数四段 ---------- */
.page-about .about-stages {
  display: grid;
  gap: 8px;
  margin: 18px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-stages__item {
  display: grid;
  gap: 4px;
  padding: 14px 18px;
  border: 1px dashed rgba(27, 26, 23, 0.2);
  border-radius: var(--radius-organic);
  background: rgba(232, 181, 74, 0.09);
}

.page-about .about-stages__range {
  font-size: 17px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--ink);
}

.page-about .about-stages__note {
  font-size: 14.5px;
  line-height: 1.72;
  color: rgba(27, 26, 23, 0.78);
}

@media (min-width: 620px) {
  .page-about .about-stages__item {
    grid-template-columns: 140px minmax(0, 1fr);
    align-items: baseline;
    gap: 18px;
  }
}

/* ---------- 规模数据 ---------- */
.page-about .about-figures {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 22px 0 0;
  overflow: hidden;
  border: 1px solid rgba(27, 26, 23, 0.16);
  border-radius: var(--radius-soft);
  background: rgba(27, 26, 23, 0.16);
}

.page-about .about-figure {
  padding: 20px 16px;
  background: var(--paper);
}

.page-about .about-figure__num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(22px, 4.4vw, 32px);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.01em;
  color: var(--ink);
}

.page-about .about-figure__num span {
  margin-left: 2px;
  font-size: 0.62em;
  color: rgba(27, 26, 23, 0.55);
}

.page-about .about-figure__note {
  margin: 8px 0 0;
  font-size: 13.5px;
  line-height: 1.6;
  color: rgba(27, 26, 23, 0.66);
}

/* ---------- 收口导航 ---------- */
.page-about .about-next {
  padding: clamp(38px, 6vw, 78px) 0 clamp(44px, 6.5vw, 86px);
  background: linear-gradient(168deg, var(--ink-deep) 0%, var(--ink-layer) 80%);
  color: var(--text-on-ink);
}

.page-about .about-next__title {
  margin: 0 0 22px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(21px, 3.6vw, 30px);
  line-height: 1.3;
  letter-spacing: 0.01em;
  color: var(--gold-light);
}

.page-about .about-next__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
}

.page-about .about-next__card {
  display: block;
  padding: 20px 20px 22px;
  border: 1px solid var(--line-hair);
  border-radius: var(--radius-organic);
  background: rgba(255, 255, 255, 0.03);
  color: var(--text-on-ink);
  text-decoration: none;
  transition: border-color 0.22s var(--ease), background-color 0.22s var(--ease), transform 0.22s var(--ease);
}

.page-about .about-next__card:hover,
.page-about .about-next__card:focus-visible {
  border-color: var(--line-gold);
  background: rgba(232, 181, 74, 0.08);
  transform: translateY(-2px);
}

.page-about .about-next__card-title {
  margin: 0 0 8px;
  font-size: 16px;
  font-weight: 700;
  color: var(--gold-light);
}

.page-about .about-next__card-text {
  margin: 0;
  font-size: 14px;
  line-height: 1.72;
  color: var(--text-mute);
}

/* ---------- 桌面端：左侧鎏金时间轴 ---------- */
@media (min-width: 980px) {
  .page-about .about-chronicle__grid {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: 60px;
  }

  .page-about .about-rail {
    order: 0;
    position: sticky;
    top: 122px;
    align-self: start;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .about-rail__list {
    display: block;
    position: relative;
    padding-left: 24px;
  }

  .page-about .about-rail__list::before {
    content: "";
    position: absolute;
    left: 5px;
    top: 10px;
    bottom: 10px;
    width: 2px;
    border-radius: 2px;
    background: linear-gradient(180deg, var(--gold) 0%, rgba(232, 181, 74, 0.16) 86%, rgba(232, 181, 74, 0) 100%);
  }

  .page-about .about-rail__item {
    position: relative;
    padding: 9px 0;
  }

  .page-about .about-rail__item::before {
    content: "";
    position: absolute;
    left: -23px;
    top: 15px;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--paper);
    border: 2px solid var(--gold);
  }

  .page-about .about-rail__link {
    display: block;
    padding: 0;
    border: 0;
    border-radius: 0;
    background: none;
    font-size: 13px;
    line-height: 1.5;
    color: rgba(27, 26, 23, 0.72);
  }

  .page-about .about-rail__link .mono {
    display: block;
    margin-bottom: 2px;
  }

  .page-about .about-rail__link:hover,
  .page-about .about-rail__link:focus-visible {
    background: none;
    color: var(--ink);
  }

  .page-about .about-rail__link:hover .mono,
  .page-about .about-rail__link:focus-visible .mono {
    color: var(--gold);
  }
}

@media (min-width: 700px) {
  .page-about .about-next__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 1040px) {
  .page-about .about-next__grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 820px) {
  .page-about .about-figures {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-next__card {
    transition: none;
  }

  .page-about .about-next__card:hover,
  .page-about .about-next__card:focus-visible {
    transform: none;
  }
}