.page-about {
  --about-gap: clamp(72px, 8vw, 124px);
  --about-side: 208px;
  --about-hair: rgba(217, 164, 65, 0.30);
  --about-soft: rgba(228, 217, 198, 0.42);
  --about-ink: rgba(27, 34, 44, 0.86);
  background: var(--paper);
  color: var(--charcoal);
  overflow-x: hidden;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  background: radial-gradient(130% 100% at 14% 0%, #14263D 0%, #0A1626 64%);
  color: var(--text);
  padding: calc(var(--mast-h) + 96px) 0 0;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-image:
    radial-gradient(1.6px 1.6px at 8% 27%, rgba(245, 238, 226, 0.78), transparent 70%),
    radial-gradient(1.3px 1.3px at 21% 13%, rgba(217, 164, 65, 0.72), transparent 70%),
    radial-gradient(1.1px 1.1px at 39% 32%, rgba(245, 238, 226, 0.54), transparent 70%),
    radial-gradient(1.5px 1.5px at 57% 17%, rgba(111, 169, 201, 0.68), transparent 70%),
    radial-gradient(1.2px 1.2px at 74% 35%, rgba(245, 238, 226, 0.58), transparent 70%),
    radial-gradient(1.4px 1.4px at 88% 20%, rgba(217, 164, 65, 0.58), transparent 70%),
    radial-gradient(1.2px 1.2px at 94% 42%, rgba(245, 238, 226, 0.44), transparent 70%);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-image:
    linear-gradient(to right, rgba(138, 151, 166, 0.14) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(138, 151, 166, 0.10) 1px, transparent 1px);
  background-size: 96px 96px, 96px 96px;
  -webkit-mask-image: radial-gradient(92% 72% at 48% 28%, #000 18%, transparent 82%);
  mask-image: radial-gradient(92% 72% at 48% 28%, #000 18%, transparent 82%);
}

.page-about .about-hero__inner {
  position: relative;
  z-index: 1;
  padding-bottom: clamp(44px, 5vw, 76px);
}

.page-about .about-crumb {
  margin-bottom: 38px;
}

.page-about .about-crumb .breadcrumb__link,
.page-about .about-crumb .breadcrumb__sep,
.page-about .about-crumb .breadcrumb__current {
  color: var(--text-dim);
  font-size: 12px;
  letter-spacing: 0.14em;
}

.page-about .about-crumb .breadcrumb__link:hover {
  color: var(--gold);
}

.page-about .about-hero__title {
  margin: 18px 0 0;
  max-width: 15em;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(32px, 5.6vw, 66px);
  line-height: 1.18;
  letter-spacing: -0.02em;
  color: var(--paper);
}

.page-about .about-hero__lede {
  max-width: 44em;
  margin: 28px 0 0;
  font-size: clamp(15px, 1.3vw, 17px);
  line-height: 1.92;
  color: var(--text-soft);
}

.page-about .about-hero__facts {
  display: flex;
  flex-wrap: wrap;
  gap: 14px 44px;
  margin: 42px 0 0;
  padding: 22px 0 0;
  list-style: none;
  border-top: 1px solid var(--about-hair);
}

.page-about .about-fact {
  display: flex;
  align-items: baseline;
  gap: 9px;
}

.page-about .about-fact__num {
  font-family: var(--font-mono);
  font-size: clamp(20px, 2.2vw, 26px);
  font-weight: 700;
  color: var(--gold);
  letter-spacing: 0.02em;
}

.page-about .about-fact__label {
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--text-dim);
}

.page-about .about-hero__figure {
  position: relative;
  z-index: 1;
  margin: 0;
  line-height: 0;
}

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

/* ---------- 横向刻度尺 ---------- */
.page-about .about-ruler {
  position: relative;
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  gap: 10px 36px;
  min-height: 76px;
  padding: 22px clamp(20px, 5vw, 72px) 16px;
  background-color: var(--paper);
  background-image: repeating-linear-gradient(90deg, rgba(138, 151, 166, 0.44) 0 1px, transparent 1px 24px);
  background-size: 100% 12px;
  background-repeat: repeat-x;
  background-position: 0 100%;
  border-bottom: 1px solid var(--line);
}

.page-about .about-ruler__mark {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--fog);
  white-space: nowrap;
}

.page-about .about-ruler__mark .num {
  color: var(--gold);
  font-weight: 700;
}

/* ---------- 主体布局 ---------- */
.page-about .about-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 44px;
  padding-top: clamp(56px, 6vw, 88px);
  padding-bottom: clamp(48px, 5vw, 72px);
}

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

.page-about .about-index__list {
  display: flex;
  flex-wrap: nowrap;
  gap: 6px;
  margin: 14px 0 0;
  padding: 0 0 10px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .about-index__link {
  display: block;
  padding: 9px 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius-pill);
  font-size: 13px;
  line-height: 1.4;
  color: var(--charcoal);
  text-decoration: none;
  white-space: nowrap;
  transition: border-color 200ms var(--ease), color 200ms var(--ease), background-color 200ms var(--ease);
}

.page-about .about-index__no {
  margin-right: 8px;
  font-size: 11px;
  color: var(--gold);
}

.page-about .about-index__link:hover,
.page-about .about-index__link:focus-visible {
  border-color: var(--red);
  background: rgba(192, 57, 47, 0.06);
}

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

/* ---------- 章节 ---------- */
.page-about .about-section {
  padding-bottom: var(--about-gap);
  scroll-margin-top: calc(var(--mast-h) + 32px);
}

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

.page-about .about-section__title {
  margin: 12px 0 0;
  max-width: 20em;
  font-family: var(--font-display);
  font-size: clamp(23px, 3.1vw, 36px);
  font-weight: 700;
  line-height: 1.34;
  letter-spacing: -0.01em;
  color: var(--charcoal);
}

.page-about .about-section__text {
  max-width: var(--measure);
  margin: 20px 0 0;
  font-size: 16px;
  line-height: 1.92;
  color: var(--about-ink);
}

/* ---------- 图 ---------- */
.page-about .about-figure {
  margin: 36px 0 0;
  max-width: var(--measure);
}

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

.page-about .about-figure--flow {
  max-width: 620px;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  border-radius: var(--radius-card);
  border: 1px solid var(--line);
  object-fit: cover;
  background: var(--nebula);
}

.page-about .about-figure__note {
  margin: 12px 0 0;
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--fog);
}

/* ---------- 阶段时间线 ---------- */
.page-about .about-eras {
  position: relative;
  max-width: var(--measure);
  margin: 40px 0 0;
  padding: 0 0 0 24px;
  list-style: none;
  border-left: 1px solid var(--line);
}

.page-about .about-era {
  position: relative;
  padding-bottom: 34px;
}

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

.page-about .about-era::before {
  content: "";
  position: absolute;
  left: -29px;
  top: 6px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--paper);
  border: 2px solid var(--gold);
}

.page-about .about-era__tag {
  margin: 0;
  color: var(--gold);
}

.page-about .about-era__title {
  margin: 8px 0 0;
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 700;
  line-height: 1.5;
  color: var(--charcoal);
}

.page-about .about-era__text {
  margin: 10px 0 0;
  font-size: 15px;
  line-height: 1.88;
  color: var(--about-ink);
}

/* ---------- 班底卡片 ---------- */
.page-about .about-crew {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  margin-top: 36px;
}

.page-about .about-crew__card {
  padding: 26px 24px 28px;
  border: 1px solid var(--line);
  border-left: 3px solid var(--gold);
  border-radius: var(--radius-card);
  background: var(--about-soft);
  transition: border-color 200ms var(--ease), background-color 200ms var(--ease);
}

.page-about .about-crew__card:hover {
  border-left-color: var(--red);
  background: rgba(228, 217, 198, 0.66);
}

.page-about .about-crew__head {
  margin: 0;
  color: var(--red);
}

.page-about .about-crew__title {
  margin: 12px 0 0;
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 700;
  line-height: 1.5;
  color: var(--charcoal);
}

.page-about .about-crew__text {
  margin: 12px 0 0;
  font-size: 15px;
  line-height: 1.88;
  color: var(--about-ink);
}

/* ---------- 四步流程 ---------- */
.page-about .about-flow {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  margin: 40px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-flow__item {
  position: relative;
  padding: 22px 20px 26px;
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  background: var(--about-soft);
  transition: transform 220ms var(--ease), border-color 220ms var(--ease), background-color 220ms var(--ease);
}

.page-about .about-flow__item:hover,
.page-about .about-flow__item:focus-within {
  transform: translateY(-4px);
  border-color: var(--red);
  background: rgba(228, 217, 198, 0.72);
}

.page-about .about-flow__bar {
  display: block;
  width: 34px;
  height: 3px;
  margin-bottom: 16px;
  background: var(--gold);
}

.page-about .about-flow__item:nth-child(2) .about-flow__bar {
  background: var(--ice);
}

.page-about .about-flow__item:nth-child(3) .about-flow__bar {
  background: var(--green);
}

.page-about .about-flow__item:nth-child(4) .about-flow__bar {
  background: var(--purple);
}

.page-about .about-flow__title {
  margin: 8px 0 0;
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 700;
  line-height: 1.4;
  color: var(--charcoal);
}

.page-about .about-flow__time {
  margin: 6px 0 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--gold);
}

.page-about .about-flow__text {
  margin: 12px 0 0;
  font-size: 14px;
  line-height: 1.86;
  color: var(--about-ink);
}

/* ---------- 防错条目 ---------- */
.page-about .about-guards {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
  max-width: var(--measure);
  margin: 34px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-guard {
  display: grid;
  grid-template-columns: 46px minmax(0, 1fr);
  gap: 14px;
  padding: 22px 0;
  border-top: 1px solid var(--line-soft);
}

.page-about .about-guard:last-child {
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-guard__num {
  font-family: var(--font-mono);
  font-size: 22px;
  font-weight: 700;
  line-height: 1.3;
  color: rgba(192, 57, 47, 0.72);
}

.page-about .about-guard__title {
  margin: 0;
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 700;
  line-height: 1.5;
  color: var(--charcoal);
}

.page-about .about-guard__text {
  margin: 9px 0 0;
  font-size: 15px;
  line-height: 1.88;
  color: var(--about-ink);
}

/* ---------- 数据之外 ---------- */
.page-about .about-beyond {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  margin-top: 36px;
}

.page-about .about-beyond__item {
  padding: 24px 22px 26px;
  border-radius: var(--radius-card);
  border: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(20, 38, 61, 0.05), rgba(20, 38, 61, 0));
}

.page-about .about-beyond__title {
  margin: 0;
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 700;
  line-height: 1.55;
  color: var(--charcoal);
}

.page-about .about-beyond__text {
  margin: 11px 0 0;
  font-size: 15px;
  line-height: 1.88;
  color: var(--about-ink);
}

.page-about .about-inline-link {
  max-width: var(--measure);
  margin: 26px 0 0;
  font-size: 14px;
  line-height: 1.9;
  color: var(--about-ink);
}

.page-about .about-inline-link a {
  color: var(--red);
  text-decoration: none;
  border-bottom: 1px solid rgba(192, 57, 47, 0.42);
  padding-bottom: 1px;
}

.page-about .about-inline-link a:hover {
  border-bottom-color: var(--red);
}

/* ---------- 路线图 ---------- */
.page-about .about-roadmap {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
  margin: 36px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-roadmap__item {
  position: relative;
  padding: 26px 24px 28px 24px;
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  background: var(--about-soft);
}

.page-about .about-roadmap__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 18px;
  bottom: 18px;
  width: 3px;
  background: var(--gold);
  border-radius: 0 2px 2px 0;
}

.page-about .about-roadmap__no {
  margin: 0;
  color: var(--fog);
}

.page-about .about-roadmap__title {
  margin: 10px 0 0;
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 700;
  line-height: 1.5;
  color: var(--charcoal);
}

.page-about .about-roadmap__text {
  margin: 11px 0 0;
  font-size: 15px;
  line-height: 1.88;
  color: var(--about-ink);
}

/* ---------- 结尾信息板 ---------- */
.page-about .about-board {
  position: relative;
  background: radial-gradient(130% 110% at 18% 0%, #14263D 0%, #0A1626 68%);
  color: var(--text);
  border-top: 1px solid var(--about-hair);
  padding: clamp(64px, 8vw, 112px) 0 clamp(56px, 6vw, 88px);
}

.page-about .about-board::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(to right, rgba(138, 151, 166, 0.12) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(138, 151, 166, 0.08) 1px, transparent 1px);
  background-size: 84px 84px, 84px 84px;
  -webkit-mask-image: radial-gradient(88% 78% at 26% 30%, #000 12%, transparent 84%);
  mask-image: radial-gradient(88% 78% at 26% 30%, #000 12%, transparent 84%);
}

.page-about .about-board__inner {
  position: relative;
  z-index: 1;
}

.page-about .about-board__title {
  margin: 16px 0 0;
  max-width: 18em;
  font-family: var(--font-display);
  font-size: clamp(26px, 3.6vw, 44px);
  font-weight: 800;
  line-height: 1.28;
  letter-spacing: -0.015em;
  color: var(--paper);
}

.page-about .about-board__lede {
  max-width: 42em;
  margin: 22px 0 0;
  font-size: 16px;
  line-height: 1.9;
  color: var(--text-soft);
}

.page-about .about-board__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 36px;
}

.page-about .about-board__stats {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 40px;
  margin: 44px 0 0;
  padding: 22px 0 0;
  list-style: none;
  border-top: 1px solid rgba(217, 164, 65, 0.22);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--text-dim);
}

.page-about .about-board__stats .num {
  margin-right: 6px;
  font-family: var(--font-mono);
  font-size: 18px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--gold);
}

/* ---------- 平板及以上 ---------- */
@media (min-width: 700px) {
  .page-about .about-crew {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-crew__card:first-child {
    grid-column: 1 / -1;
  }

  .page-about .about-beyond {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-roadmap {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-flow {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    align-items: end;
    gap: 16px;
  }

  .page-about .about-flow__item:nth-child(1) {
    --step-h: 52px;
  }

  .page-about .about-flow__item:nth-child(2) {
    --step-h: 96px;
  }

  .page-about .about-flow__item:nth-child(3) {
    --step-h: 140px;
  }

  .page-about .about-flow__item:nth-child(4) {
    --step-h: 184px;
  }

  .page-about .about-flow__item::after {
    content: "";
    position: absolute;
    left: 50%;
    bottom: 100%;
    width: 1px;
    height: var(--step-h, 0px);
    transform: translateX(-50%);
    background: linear-gradient(to top, var(--gold), rgba(217, 164, 65, 0.06));
    pointer-events: none;
  }

  .page-about .about-flow {
    margin-top: 200px;
  }
}

/* ---------- 桌面：非对称双栏 ---------- */
@media (min-width: 1000px) {
  .page-about .about-layout {
    grid-template-columns: var(--about-side) minmax(0, 1fr);
    gap: 64px;
  }

  .page-about .about-index {
    position: sticky;
    top: calc(var(--mast-h) + 36px);
    align-self: start;
  }

  .page-about .about-index__list {
    flex-direction: column;
    flex-wrap: nowrap;
    gap: 0;
    overflow: visible;
    padding-bottom: 0;
    border-left: 1px solid var(--line-soft);
    margin-top: 16px;
  }

  .page-about .about-index__link {
    border: 0;
    border-radius: 0;
    padding: 10px 0 10px 15px;
    margin-left: -1px;
    border-left: 1px solid transparent;
    color: var(--fog);
    white-space: normal;
    font-size: 13px;
  }

  .page-about .about-index__link:hover,
  .page-about .about-index__link:focus-visible {
    border-left-color: var(--red);
    background: transparent;
    color: var(--charcoal);
  }

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

  .page-about .about-crew__card:first-child {
    grid-column: auto;
  }

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

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

/* ---------- 减少动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .about-flow__item,
  .page-about .about-crew__card,
  .page-about .about-index__link {
    transition: none;
  }

  .page-about .about-flow__item:hover,
  .page-about .about-flow__item:focus-within {
    transform: none;
  }
}