.page-about {
  --about-ink: #12241B;
  --about-pad: clamp(48px, 7vw, 88px);
  background: var(--ink);
  color: var(--paper);
}

.page-about .crumb {
  padding-top: 20px;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: 32px 0 var(--about-pad);
  border-bottom: 1px solid var(--edge);
}

.page-about .about-hero__img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.32;
  filter: saturate(0.75);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background:
    linear-gradient(180deg, rgba(8, 22, 15, 0.55) 0%, rgba(8, 22, 15, 0.92) 62%, var(--ink) 100%),
    repeating-linear-gradient(90deg, rgba(215, 255, 60, 0.05) 0 2px, transparent 2px 42px);
  pointer-events: none;
}

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

.page-about .about-hero .eyebrow {
  display: block;
  margin-bottom: 18px;
}

.page-about .about-hero__title {
  margin: 0 0 20px;
  max-width: 18ch;
  font-family: var(--font-sans);
  font-size: clamp(30px, 7vw, 46px);
  font-weight: 900;
  line-height: 1.18;
  letter-spacing: -0.01em;
  color: var(--paper);
}

.page-about .about-hero__lede {
  margin: 0 0 34px;
  max-width: 60ch;
  font-size: 16px;
  line-height: 1.85;
  color: rgba(234, 243, 236, 0.82);
}

.page-about .about-hero__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
  background: var(--edge-soft);
  border: 1px solid var(--edge-soft);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .about-hero__fact {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 18px 16px;
  background: rgba(11, 28, 20, 0.78);
}

.page-about .about-hero__num {
  font-family: var(--font-mono);
  font-size: 32px;
  font-weight: 700;
  line-height: 1;
  color: var(--lime);
}

.page-about .about-hero__cap {
  font-size: 13px;
  line-height: 1.5;
  color: var(--muted);
}

/* ---------- 章节通用骨架 ---------- */
.page-about .about-sec {
  padding: var(--about-pad) 0;
  border-bottom: 1px solid var(--edge-soft);
}

.page-about .about-sec--paper {
  background: var(--light);
  color: var(--about-ink);
}

.page-about .about-sec--field {
  background: var(--field);
}

.page-about .about-sec--indigo {
  background: var(--indigo);
}

.page-about .about-sec--principles {
  background:
    radial-gradient(120% 90% at 12% 0%, rgba(215, 255, 60, 0.09) 0%, transparent 62%),
    var(--ink);
}

.page-about .about-sec__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 26px;
}

.page-about .about-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 12px;
}

.page-about .about-head__idx {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--lime);
  padding-bottom: 2px;
  border-bottom: 1px solid var(--edge);
}

.page-about .about-head__title {
  flex: 1 1 100%;
  margin: 0;
  font-size: clamp(21px, 4.6vw, 27px);
  font-weight: 800;
  line-height: 1.4;
  color: inherit;
}

.page-about .about-head__note {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .about-sec--paper .about-head__idx {
  color: #6F8A2E;
  border-bottom-color: rgba(18, 36, 27, 0.2);
}

.page-about .about-sec--paper .about-head__note {
  color: rgba(18, 36, 27, 0.5);
}

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

.page-about .about-body p {
  margin: 0 0 16px;
  font-size: 16px;
  line-height: 1.85;
  color: rgba(234, 243, 236, 0.82);
}

.page-about .about-sec--paper .about-body p {
  color: rgba(18, 36, 27, 0.8);
}

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

.page-about .about-body a {
  color: var(--lime);
  text-decoration: none;
  border-bottom: 1px solid rgba(215, 255, 60, 0.42);
  padding-bottom: 1px;
}

.page-about .about-body a:hover {
  border-bottom-color: var(--lime);
}

.page-about .about-sec--paper .about-body a {
  color: #4C6A12;
  border-bottom-color: rgba(76, 106, 18, 0.4);
}

.page-about .about-body__tail {
  margin-top: 22px !important;
  padding-top: 18px;
  border-top: 1px dashed var(--edge-soft);
}

.page-about .about-sec--paper .about-body__tail {
  border-top-color: rgba(18, 36, 27, 0.16);
}

/* ---------- 配图 ---------- */
.page-about .about-figure {
  margin: 26px 0 0;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--edge-soft);
  background: var(--ink-2);
}

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

.page-about .about-figure__cap {
  padding: 12px 16px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--muted);
  border-top: 1px solid var(--edge-soft);
}

.page-about .about-sec--paper .about-figure__cap {
  color: rgba(18, 36, 27, 0.62);
  border-top-color: rgba(18, 36, 27, 0.14);
}

/* ---------- 版本时间线 ---------- */
.page-about .version-track {
  position: relative;
  margin: 30px 0 0;
  padding: 0 0 0 34px;
  list-style: none;
}

.page-about .version-track::before {
  content: "";
  position: absolute;
  left: 9px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  border-radius: 2px;
  background: linear-gradient(180deg, var(--lime) 0%, rgba(215, 255, 60, 0.35) 55%, rgba(215, 255, 60, 0.06) 100%);
}

.page-about .version-node {
  position: relative;
  margin-bottom: 18px;
}

.page-about .version-node:last-child {
  margin-bottom: 0;
}

.page-about .version-node::before {
  content: "";
  position: absolute;
  left: -34px;
  top: 26px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--lime);
  box-shadow: 0 0 0 4px rgba(215, 255, 60, 0.14), 0 0 16px rgba(215, 255, 60, 0.55);
}

.page-about .version-node__box {
  padding: 18px 18px 20px;
  border-radius: var(--radius);
  background: var(--glass);
  border: 1px solid var(--edge-soft);
  transition: transform 0.25s ease, border-color 0.25s ease, box-shadow 0.25s ease;
}

.page-about .version-node:hover .version-node__box,
.page-about .version-node:focus-within .version-node__box {
  transform: translateY(-3px);
  border-color: var(--edge);
  box-shadow: 0 14px 32px rgba(0, 0, 0, 0.38);
}

.page-about .version-node__ver {
  display: inline-block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 24px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--lime);
}

.page-about .version-node__title {
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 700;
  line-height: 1.5;
  color: var(--paper);
}

.page-about .version-node__desc {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: rgba(234, 243, 236, 0.76);
}

/* ---------- 大屏能力分栏 ---------- */
.page-about .about-split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 24px;
}

.page-about .about-split__text p {
  margin: 0 0 16px;
}

.page-about .about-bullets {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
  background: var(--edge-soft);
  border: 1px solid var(--edge-soft);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .about-bullets__item {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px;
  padding: 16px;
  background: rgba(8, 22, 15, 0.62);
}

.page-about .about-bullets__num {
  font-family: var(--font-mono);
  font-size: 26px;
  font-weight: 700;
  line-height: 1;
  color: var(--lime);
}

.page-about .about-bullets__cap {
  flex: 1 1 60%;
  font-size: 14px;
  line-height: 1.6;
  color: var(--muted);
}

/* ---------- 使用人群 ---------- */
.page-about .audience-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
}

.page-about .audience-card {
  position: relative;
  padding: 22px 20px 24px;
  overflow: hidden;
}

.page-about .audience-card::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: linear-gradient(180deg, var(--lime), rgba(215, 255, 60, 0.1));
}

.page-about .audience-card__idx {
  display: block;
  margin-bottom: 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--lime-dim);
}

.page-about .audience-card .card__title {
  margin: 0 0 10px;
  font-size: 17px;
}

.page-about .audience-card__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: rgba(234, 243, 236, 0.78);
}

/* ---------- 协作数据 ---------- */
.page-about .about-metrics {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin: 22px 0 0;
}

.page-about .about-metric {
  padding: 20px 18px;
  border-radius: var(--radius);
  border: 1px solid rgba(215, 255, 60, 0.2);
  background: rgba(8, 22, 15, 0.42);
}

.page-about .about-metric__num {
  font-family: var(--font-mono);
  font-size: 38px;
  font-weight: 700;
  line-height: 1;
  color: var(--lime);
}

.page-about .about-metric__unit {
  margin-left: 6px;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--lime-dim);
}

.page-about .about-metric__cap {
  display: block;
  margin-top: 10px;
  font-size: 14px;
  line-height: 1.6;
  color: rgba(234, 243, 236, 0.74);
}

/* ---------- 三条底线 ---------- */
.page-about .principle-list {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
  background: var(--edge-soft);
  border: 1px solid var(--edge-soft);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .principle-item {
  display: flex;
  align-items: flex-start;
  gap: 16px;
  padding: 22px 20px;
  background: rgba(11, 28, 20, 0.86);
}

.page-about .principle-item__idx {
  flex: 0 0 auto;
  width: 32px;
  height: 32px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  color: var(--ink);
  background: var(--lime);
}

.page-about .principle-item__text {
  margin: 0;
  font-size: 16px;
  line-height: 1.8;
  color: rgba(234, 243, 236, 0.86);
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .about-hero__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

  .page-about .about-bullets__item {
    flex-direction: column;
    gap: 8px;
  }

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

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

@media (min-width: 900px) {
  .page-about .about-sec__grid {
    grid-template-columns: minmax(0, 280px) minmax(0, 1fr);
    gap: 56px;
    align-items: start;
  }

  .page-about .about-head {
    position: sticky;
    top: 40px;
    flex-direction: column;
    align-items: flex-start;
    gap: 14px;
  }

  .page-about .about-head__title {
    flex: 0 0 auto;
    font-size: 26px;
    line-height: 1.42;
  }

  .page-about .about-split {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    gap: 40px;
    align-items: start;
  }

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

  .page-about .audience-card:nth-child(2) {
    transform: translateY(14px);
  }
}

@media (min-width: 1200px) {
  .page-about .about-hero__title {
    font-size: 48px;
  }

  .page-about .version-track {
    padding-left: 42px;
  }

  .page-about .version-node::before {
    left: -42px;
  }
}

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

  .page-about .version-node:hover .version-node__box,
  .page-about .version-node:focus-within .version-node__box {
    transform: none;
  }

  .page-about .audience-card:nth-child(2) {
    transform: none;
  }
}