.page-about {
  --about-radius: 22px;
  --about-rail: 20px;
  --about-gap: 24px;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding-top: calc(var(--header-h) + var(--space-4));
  padding-bottom: var(--space-6);
}

.page-about .breadcrumb {
  margin-bottom: var(--space-4);
  font-size: 13px;
}

.page-about .hero-frame {
  position: relative;
  border: 1px solid var(--rule);
  border-radius: var(--radius-lg);
  padding: clamp(28px, 6vw, 60px) clamp(20px, 5vw, 56px) clamp(26px, 5vw, 52px);
  overflow: hidden;
  background:
    radial-gradient(120% 100% at 88% 0%, rgba(199, 249, 74, 0.12), transparent 58%),
    radial-gradient(90% 90% at 0% 100%, rgba(79, 209, 197, 0.1), transparent 62%),
    var(--panel);
}

.page-about .hero-frame::before {
  content: "";
  position: absolute;
  top: 16px;
  left: 16px;
  right: 16px;
  height: 7px;
  pointer-events: none;
  background-image: repeating-linear-gradient(90deg, var(--rule) 0 1px, transparent 1px 26px);
  opacity: 0.85;
}

.page-about .hero-frame::after {
  content: "";
  position: absolute;
  right: 18px;
  bottom: 18px;
  width: 16px;
  height: 16px;
  border-right: 1px solid var(--lime);
  border-bottom: 1px solid var(--lime);
  opacity: 0.65;
  pointer-events: none;
}

.page-about .hero-meta {
  margin: 0 0 var(--space-3);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--lime);
  text-transform: uppercase;
}

.page-about .about-hero h1 {
  margin: 0 0 var(--space-3);
  max-width: 22ch;
  font-size: var(--fs-h1);
  font-weight: 900;
  line-height: 1.12;
  letter-spacing: -0.02em;
}

.page-about .about-hero .lede {
  max-width: 640px;
  color: var(--mist);
  opacity: 0.86;
}

.page-about .hero-stats {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--space-3);
  margin: var(--space-8) 0 0;
  padding: var(--space-4) 0 0;
  border-top: 1px solid var(--rule);
}

.page-about .hero-stats li {
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-width: 0;
}

.page-about .hero-stats__n {
  font-size: clamp(1.5rem, 4vw, 2.25rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.01em;
  color: var(--lime);
  border-bottom: 2px solid var(--rule);
  padding-bottom: 8px;
}

.page-about .hero-stats__l {
  font-size: 12px;
  line-height: 1.6;
  color: var(--stone);
  font-family: var(--font-display);
}

.page-about .hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: var(--space-6);
}

/* ---------- 章节锚点 ---------- */
.page-about .about-anchors {
  margin-bottom: var(--space-4);
}

.page-about .about-anchors .pill-row {
  list-style: none;
  margin: 0;
  padding: 0 0 6px;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  overflow-x: auto;
}

.page-about .about-anchors li {
  list-style: none;
  flex: 0 0 auto;
}

.page-about .about-anchors a.pill {
  text-decoration: none;
  white-space: nowrap;
}

/* ---------- 阶段章节通用 ---------- */
.page-about .about-stage {
  display: grid;
  grid-template-columns: var(--about-rail) minmax(0, 1fr);
  column-gap: var(--space-3);
  padding: var(--space-8) 0;
  border-top: 1px solid var(--rule);
  scroll-margin-top: calc(var(--header-h) + 16px);
}

.page-about .stage-rail {
  position: relative;
  display: flex;
  justify-content: center;
  padding-top: 10px;
}

.page-about .stage-rail::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: calc(-1 * var(--space-8));
  left: 50%;
  width: 1px;
  transform: translateX(-0.5px);
  background: var(--rule);
}

.page-about .about-stage:last-of-type .stage-rail::before {
  bottom: 0;
}

.page-about .stage-rail__dot {
  position: relative;
  width: 9px;
  height: 9px;
  margin-top: 6px;
  border-radius: var(--radius-pill);
  background: transparent;
  border: 1px solid var(--stone);
  transition: background 0.24s var(--ease), border-color 0.24s var(--ease), box-shadow 0.24s var(--ease);
}

.page-about .about-stage:has(.section__title.is-active) .stage-rail__dot {
  background: var(--lime);
  border-color: var(--lime);
  box-shadow: 0 0 0 5px rgba(199, 249, 74, 0.14);
}

.page-about .about-stage .section__head {
  margin-bottom: var(--space-4);
}

.page-about .about-stage .section__title {
  max-width: 620px;
  font-size: var(--fs-h2);
  line-height: 1.24;
  letter-spacing: -0.02em;
}

.page-about .about-stage .section__body p {
  max-width: 62ch;
  color: var(--mist);
  opacity: 0.88;
}

.page-about .about-stage .section__body a {
  color: var(--aqua);
}

/* ---------- 图 ---------- */
.page-about .figure-frame {
  margin: 0;
}

.page-about .figure-frame__cap {
  margin-top: 10px;
  font-size: 12px;
  line-height: 1.7;
  color: var(--stone);
}

.page-about .stage-body > .figure-frame {
  margin-top: var(--space-6);
}

/* ---------- 内容方法 ---------- */
.page-about .method-top {
  display: grid;
  gap: var(--space-6);
  margin-bottom: var(--space-6);
}

.page-about .method-grid {
  display: grid;
  gap: var(--space-3);
  margin-top: var(--space-4);
}

.page-about .method-card {
  --card-accent: var(--lime);
  border-radius: var(--about-radius);
  padding: var(--space-4) var(--space-3);
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.page-about .method-card:nth-child(2) {
  --card-accent: var(--aqua);
}

.page-about .method-card:nth-child(3) {
  --card-accent: var(--red);
}

.page-about .method-card__tag {
  margin: 0;
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--card-accent);
}

.page-about .method-card h3 {
  margin: 0;
  font-size: 1.0625rem;
  letter-spacing: -0.01em;
}

.page-about .method-card p:last-child {
  margin: 0;
  font-size: 14px;
  line-height: 1.85;
  color: var(--stone);
}

/* ---------- 时间线 ---------- */
.page-about .timeline {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .timeline__item {
  position: relative;
  display: grid;
  grid-template-columns: 11px minmax(0, 1fr);
  column-gap: 14px;
  padding-bottom: var(--space-6);
}

.page-about .timeline__item:not(:last-child)::after {
  content: "";
  position: absolute;
  left: 5px;
  top: 22px;
  bottom: -4px;
  width: 1px;
  background: linear-gradient(180deg, var(--rule), rgba(42, 59, 54, 0.25));
}

.page-about .timeline__node {
  width: 9px;
  height: 9px;
  margin-top: 5px;
  justify-self: center;
  border-radius: var(--radius-pill);
  background: var(--lime);
  box-shadow: 0 0 0 4px rgba(199, 249, 74, 0.1);
}

.page-about .timeline__item:last-child .timeline__node {
  background: var(--red);
  box-shadow: 0 0 0 4px rgba(226, 69, 58, 0.14);
}

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

.page-about .timeline__when {
  margin: 0 0 6px;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--stone);
}

.page-about .timeline__what {
  margin: 0 0 6px;
  font-size: 1.0625rem;
  line-height: 1.5;
  letter-spacing: -0.01em;
}

.page-about .timeline__desc {
  margin: 0;
  max-width: 58ch;
  font-size: var(--fs-body);
  line-height: 1.88;
  color: var(--stone);
}

/* ---------- 现场 ---------- */
.page-about .culture-figure {
  margin-top: var(--space-6);
  border-radius: var(--radius-md);
  overflow: hidden;
}

/* ---------- 收藏价值 ---------- */
.page-about .keep-table {
  display: grid;
  margin: var(--space-6) 0;
}

.page-about .keep-table dt {
  margin: 0;
  padding: var(--space-4) 0 4px;
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--lime);
}

.page-about .keep-table dd {
  margin: 0;
  padding: 0 0 var(--space-4);
  font-size: var(--fs-body);
  line-height: 1.88;
  color: var(--mist);
  opacity: 0.82;
  border-bottom: 1px solid var(--rule);
}

.page-about .stage-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: var(--space-6) 0 0;
  max-width: none;
}

.page-about .stage-note {
  margin-top: var(--space-4);
  font-size: 14px;
  line-height: 1.9;
  color: var(--stone);
}

/* ---------- 阅读模式预览 ---------- */
.page-about .mode-preview {
  display: grid;
  gap: var(--space-3);
  margin-top: var(--space-6);
}

.page-about .mode-pane {
  min-height: 132px;
  padding: var(--space-4);
  border-radius: var(--about-radius);
  border: 1px solid var(--rule);
}

.page-about .mode-pane--night {
  background: linear-gradient(180deg, #0E1726, #0B1A16);
  color: #E8F0EA;
  border-color: #253829;
}

.page-about .mode-pane--day {
  background: linear-gradient(180deg, #F4F8F5, #E4EDE7);
  color: #0B1A16;
  border-color: #C7D5CD;
}

.page-about .mode-pane__tag {
  margin: 0 0 14px;
  font-size: 11px;
  letter-spacing: 0.14em;
  opacity: 0.66;
}

.page-about .mode-pane__bar {
  display: block;
  height: 8px;
  margin-top: 10px;
  border-radius: var(--radius-pill);
  background: currentColor;
  opacity: 0.2;
}

.page-about .mode-pane__bar--short {
  width: 62%;
}

.page-about .mode-pane__bar--tiny {
  width: 38%;
}

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

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

@media (min-width: 768px) {
  .page-about .method-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .timeline__item {
    grid-template-columns: 14px minmax(0, 1fr);
    column-gap: var(--space-3);
  }

  .page-about .timeline__item:not(:last-child)::after {
    left: 6.5px;
  }

  .page-about .timeline__node {
    width: 11px;
    height: 11px;
  }
}

@media (min-width: 860px) {
  .page-about .method-top {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.02fr);
    align-items: start;
    gap: var(--space-6);
  }

  .page-about .method-card {
    padding: var(--space-4);
  }

  .page-about .keep-table {
    grid-template-columns: minmax(0, 0.72fr) minmax(0, 1.55fr);
    column-gap: var(--space-6);
  }

  .page-about .keep-table dt {
    padding: var(--space-4) 0;
    border-bottom: 1px solid var(--rule);
  }

  .page-about .keep-table dd {
    padding: var(--space-4) 0;
  }
}

@media (min-width: 960px) {
  .page-about {
    --about-rail: 56px;
  }

  .page-about .about-stage {
    column-gap: var(--space-6);
    padding: var(--space-12) 0;
  }

  .page-about .stage-rail::before {
    bottom: calc(-1 * var(--space-12));
  }

  .page-about .stage-rail__dot {
    width: 11px;
    height: 11px;
    margin-top: 8px;
  }

  .page-about .about-anchors {
    margin-bottom: var(--space-6);
  }
}

@media (min-width: 1200px) {
  .page-about .hero-frame {
    padding-left: 72px;
    padding-right: 72px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .stage-rail__dot {
    transition: none;
  }
}
</main>