.page-about {
  --about-axis: 30px;
  --about-node: 11px;
  background: var(--ink);
  color: var(--white);
  overflow-x: clip;
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumbs {
  display: flex;
  align-items: center;
  gap: 8px;
  padding-top: 18px;
  font-size: 13px;
}
.page-about .crumb {
  color: var(--mist);
  text-decoration: none;
  transition: color 0.2s var(--ease);
}
.page-about .crumb:hover {
  color: var(--cyan);
}
.page-about .crumb--current {
  color: var(--paper);
}
.page-about .crumb-sep {
  color: var(--cyan-dim);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(32px, 5vw, 56px) 0 clamp(44px, 7vw, 82px);
  border-bottom: 1px solid var(--line-mid);
  background:
    radial-gradient(120% 96% at 86% 0%, rgba(59, 240, 196, 0.09), transparent 62%),
    linear-gradient(180deg, var(--pitch), var(--ink));
}
.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(90deg, rgba(59, 240, 196, 0.055) 1px, transparent 1px),
    linear-gradient(180deg, rgba(59, 240, 196, 0.035) 1px, transparent 1px);
  background-size: 76px 76px, 76px 76px;
  -webkit-mask-image: radial-gradient(118% 100% at 72% 0%, #000 22%, transparent 78%);
  mask-image: radial-gradient(118% 100% at 72% 0%, #000 22%, transparent 78%);
  pointer-events: none;
}
.page-about .about-hero__inner {
  position: relative;
  display: grid;
  gap: clamp(30px, 5vw, 56px);
}
.page-about .about-hero__vlabel {
  display: inline-block;
  font-size: 12px;
  letter-spacing: 0.34em;
  color: var(--cyan);
  margin-bottom: 16px;
}
.page-about .about-hero__title {
  margin: 0;
  font-weight: 900;
  letter-spacing: -0.015em;
  line-height: 1.14;
  color: var(--white);
  text-wrap: balance;
}
.page-about .about-hero__text {
  margin: 20px 0 0;
  max-width: 46em;
  color: var(--mist);
}
.page-about .about-hero__links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.page-about .about-hero__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 0;
  background: var(--line-mid);
  border: 1px solid var(--line-mid);
}
.page-about .about-hero__stat {
  background: var(--pitch);
  padding: 16px 16px 18px;
}
.page-about .about-hero__stat dt {
  font-size: 12.5px;
  color: var(--mist);
  letter-spacing: 0.04em;
}
.page-about .about-hero__stat dd {
  margin: 8px 0 0;
  font-size: clamp(26px, 4vw, 34px);
  line-height: 1;
  font-weight: 700;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}

/* ---------- 时间轴 ---------- */
.page-about .about-timeline {
  padding-top: clamp(48px, 7vw, 84px);
}
.page-about .about-timeline__grid {
  display: grid;
  gap: clamp(34px, 5vw, 56px);
}
.page-about .about-timeline__eyebrow {
  margin: 0 0 10px;
  color: var(--cyan);
}
.page-about .about-timeline__heading {
  margin: 0;
  line-height: 1.2;
}
.page-about .about-timeline__nav {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: grid;
  border-top: 1px solid var(--line-mid);
}
.page-about .about-timeline__nav li {
  border-bottom: 1px solid var(--line-mid);
}
.page-about .about-timeline__nav .toc-link {
  display: block;
  padding: 12px 0;
  font-size: 14px;
  color: var(--mist);
  text-decoration: none;
  transition: color 0.22s var(--ease), padding-left 0.22s var(--ease);
}
.page-about .about-timeline__nav .toc-link:hover,
.page-about .about-timeline__nav .toc-link[aria-current="true"] {
  color: var(--cyan);
  padding-left: 8px;
}

.page-about .about-timeline__track {
  position: relative;
  padding-left: var(--about-axis);
}
.page-about .about-timeline__track::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 12px;
  bottom: 28px;
  width: 1px;
  background: linear-gradient(180deg, var(--line-cyan) 0%, var(--line-mid) 58%, transparent 100%);
}

.page-about .stage {
  position: relative;
  padding-bottom: clamp(40px, 6vw, 76px);
}
.page-about .stage:last-child {
  padding-bottom: 0;
}
.page-about .stage::before {
  content: "";
  position: absolute;
  top: 13px;
  left: calc(var(--about-axis) * -1 + 5px);
  width: var(--about-node);
  height: var(--about-node);
  transform: translateX(-50%) rotate(45deg);
  background: var(--ink);
  border: 1px solid var(--cyan-dim);
  transition: background 0.4s var(--ease), border-color 0.4s var(--ease), box-shadow 0.4s var(--ease);
}
.page-about .stage.is-in::before {
  background: var(--cyan);
  border-color: var(--cyan);
  box-shadow: 0 0 0 5px rgba(59, 240, 196, 0.13);
}

.page-about .stage__inner {
  display: grid;
  gap: 14px;
}
.page-about .stage__marks {
  display: flex;
  align-items: baseline;
  gap: 12px;
}
.page-about .stage__year {
  font-size: clamp(32px, 5.4vw, 48px);
  line-height: 1;
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--paper);
  font-variant-numeric: tabular-nums;
}
.page-about .stage__label {
  font-size: 12px;
  letter-spacing: 0.32em;
  color: var(--cyan);
}
.page-about .stage__body .t-sub {
  margin: 0 0 12px;
  line-height: 1.3;
  color: var(--white);
}
.page-about .stage__body .t-body {
  margin: 0 0 14px;
  color: var(--mist);
}
.page-about .stage__body .t-body:last-of-type {
  margin-bottom: 0;
}

.page-about .stage__facts {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line-mid);
  border: 1px solid var(--line-mid);
}
.page-about .stage__facts li {
  background: var(--pitch);
  padding: 14px 16px;
  display: grid;
  gap: 6px;
}
.page-about .stage__facts .num {
  font-size: 22px;
  font-weight: 700;
  line-height: 1;
  font-variant-numeric: tabular-nums;
}
.page-about .stage__facts span:last-child {
  font-size: 12.5px;
  color: var(--mist);
  letter-spacing: 0.02em;
}

.page-about .stage__figure {
  margin: 26px 0 0;
}
.page-about .stage__figure .media-frame {
  overflow: hidden;
  border: 1px solid var(--line-mid);
}
.page-about .frame-caption,
.page-about .figure-caption {
  margin-top: 10px;
  font-size: 12.5px;
  color: var(--mist);
  line-height: 1.7;
}

.page-about .stage__matrix {
  display: grid;
  gap: 10px;
  margin-top: 22px;
}
.page-about .matrix-chip {
  border: 1px solid var(--line-mid);
  border-left: 2px solid var(--flame);
  background: rgba(18, 48, 39, 0.55);
  padding: 14px 16px;
  transition: border-color 0.25s var(--ease), transform 0.25s var(--ease);
}
.page-about .matrix-chip:hover {
  border-color: var(--line-cyan);
  border-left-color: var(--cyan);
  transform: translateY(-2px);
}
.page-about .matrix-chip__tag {
  display: inline-block;
  font-size: 11.5px;
  letter-spacing: 0.16em;
  color: var(--amber);
}
.page-about .matrix-chip__name {
  margin: 8px 0 4px;
  font-size: 16px;
  font-weight: 700;
  color: var(--white);
}
.page-about .matrix-chip__desc {
  margin: 0;
  font-size: 13px;
  line-height: 1.7;
  color: var(--mist);
}

/* ---------- 暖纸色团队区 ---------- */
.page-about .about-paper {
  background: var(--paper);
  color: var(--ink);
  padding: clamp(48px, 8vw, 92px) 0;
  border-top: 1px solid var(--paper-dim);
  border-bottom: 1px solid var(--paper-dim);
}
.page-about .about-paper__eyebrow {
  margin: 0 0 10px;
  color: var(--cyan-dim);
  letter-spacing: 0.3em;
}
.page-about .about-paper h2,
.page-about .about-paper h3 {
  color: var(--ink);
}
.page-about .about-paper__intro .t-title {
  margin: 0;
  line-height: 1.18;
}
.page-about .about-paper__grid {
  display: grid;
  gap: clamp(28px, 4vw, 48px);
  margin-top: clamp(28px, 4vw, 44px);
}
.page-about .about-paper__text p {
  margin: 0 0 18px;
  font-size: 16.5px;
  line-height: 1.85;
  color: #2C3D36;
}
.page-about .about-paper__text p:last-child {
  margin-bottom: 0;
}
.page-about .about-paper__text p:first-child::first-letter {
  float: left;
  font-size: 54px;
  line-height: 0.84;
  font-weight: 900;
  color: var(--flame);
  margin: 6px 12px 0 0;
}
.page-about .about-paper__figure {
  margin: 0;
}
.page-about .about-paper__figure .media-frame {
  overflow: hidden;
  border: 1px solid var(--paper-dim);
}
.page-about .about-paper__figure .figure-caption {
  margin-top: 10px;
  font-size: 12.5px;
  color: #5C6C65;
  line-height: 1.7;
}

.page-about .team-grid {
  display: grid;
  gap: 14px;
  margin-top: clamp(30px, 4vw, 44px);
}
.page-about .team-card {
  position: relative;
  background: #FBF8F1;
  border: 1px solid var(--paper-dim);
  border-radius: var(--radius);
  padding: 22px 20px;
  outline: none;
  transition: transform 0.25s var(--ease), box-shadow 0.25s var(--ease), border-color 0.25s var(--ease);
}
.page-about .team-card:hover,
.page-about .team-card:focus-within,
.page-about .team-card:focus {
  transform: translateY(-2px);
  box-shadow: 0 12px 26px rgba(11, 26, 21, 0.1);
  border-color: var(--cyan-dim);
}
.page-about .team-card__role {
  margin: 0;
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--cyan-dim);
}
.page-about .team-card__num {
  margin: 10px 0 8px;
  font-size: clamp(30px, 4vw, 40px);
  line-height: 1;
  font-weight: 800;
  color: var(--ink);
  font-variant-numeric: tabular-nums;
}
.page-about .team-card__desc {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.75;
  color: #4C5C55;
}
.page-about .team-card__bubble {
  max-height: 0;
  opacity: 0;
  overflow: hidden;
  padding-top: 0;
  margin-top: 0;
  border-top: 1px dashed var(--paper-dim);
  font-size: 13px;
  line-height: 1.75;
  color: #3E4F48;
  transition: max-height 0.4s var(--ease), opacity 0.3s var(--ease), padding-top 0.34s var(--ease), margin-top 0.34s var(--ease);
}
.page-about .team-card:hover .team-card__bubble,
.page-about .team-card:focus .team-card__bubble,
.page-about .team-card:focus-within .team-card__bubble {
  max-height: 260px;
  opacity: 1;
  padding-top: 12px;
  margin-top: 14px;
}

/* ---------- 数据来源 ---------- */
.page-about .about-sources {
  padding-top: clamp(48px, 7vw, 88px);
  padding-bottom: clamp(48px, 7vw, 88px);
}
.page-about .about-sources__head {
  display: grid;
  gap: 20px;
}
.page-about .about-sources__eyebrow {
  margin: 0 0 10px;
  color: var(--cyan);
}
.page-about .about-sources__head .t-title {
  margin: 0;
  line-height: 1.2;
}
.page-about .about-sources__lede {
  margin: 0;
  color: var(--mist);
  max-width: 48em;
}

.page-about .source-list {
  list-style: none;
  margin: clamp(30px, 4vw, 46px) 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line-mid);
  border-top: 1px solid var(--line-mid);
  border-bottom: 1px solid var(--line-mid);
}
.page-about .source-item {
  background: var(--ink);
  display: grid;
  grid-template-columns: 46px minmax(0, 1fr);
  gap: 14px;
  padding: 20px 4px;
  transition: background 0.3s var(--ease);
}
.page-about .source-item:hover {
  background: var(--pitch);
}
.page-about .source-item__idx {
  font-size: 20px;
  font-weight: 700;
  line-height: 1.2;
  color: var(--cyan-dim);
  font-variant-numeric: tabular-nums;
  transition: color 0.3s var(--ease);
}
.page-about .source-item:hover .source-item__idx {
  color: var(--flame);
}
.page-about .source-item__body .t-sub {
  margin: 0 0 8px;
  color: var(--white);
}
.page-about .source-item__body .t-body {
  margin: 0;
  color: var(--mist);
}

/* ---------- 长期约定 ---------- */
.page-about .about-habits {
  padding-top: clamp(48px, 7vw, 88px);
  padding-bottom: clamp(48px, 7vw, 88px);
  border-top: 1px solid var(--line-mid);
  background: linear-gradient(180deg, rgba(18, 48, 39, 0.5), transparent 70%);
}
.page-about .about-habits__eyebrow {
  margin: 0 0 10px;
  color: var(--amber);
}
.page-about .about-habits .t-title {
  margin: 0;
  line-height: 1.2;
}
.page-about .habit-grid {
  display: grid;
  gap: 14px;
  margin-top: clamp(28px, 4vw, 44px);
}
.page-about .habit-card {
  position: relative;
  border: 1px solid var(--line-mid);
  background: rgba(11, 26, 21, 0.7);
  padding: 22px 20px 24px;
  transition: border-color 0.28s var(--ease), transform 0.28s var(--ease);
}
.page-about .habit-card::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  height: 2px;
  width: 40%;
  background: linear-gradient(90deg, var(--flame), transparent);
}
.page-about .habit-card:hover {
  border-color: var(--line-cyan);
  transform: translateY(-2px);
}
.page-about .habit-card__mark {
  display: block;
  font-size: clamp(24px, 3.4vw, 30px);
  font-weight: 700;
  line-height: 1;
  color: var(--flame);
  font-variant-numeric: tabular-nums;
}
.page-about .habit-card .t-sub {
  margin: 14px 0 8px;
  color: var(--white);
}
.page-about .habit-card .t-body {
  margin: 0;
  color: var(--mist);
}

/* ---------- 后续入口 ---------- */
.page-about .about-next {
  padding-top: clamp(48px, 7vw, 88px);
  padding-bottom: clamp(56px, 8vw, 100px);
  border-top: 1px solid var(--line-mid);
}
.page-about .about-next__heading {
  margin: 0;
  line-height: 1.2;
}
.page-about .about-next__grid {
  display: grid;
  gap: 12px;
  margin-top: clamp(26px, 4vw, 40px);
}
.page-about .next-card {
  display: grid;
  gap: 8px;
  padding: 22px 20px;
  border: 1px solid var(--line-mid);
  text-decoration: none;
  background: rgba(18, 48, 39, 0.4);
  transition: border-color 0.28s var(--ease), background 0.28s var(--ease), transform 0.28s var(--ease);
}
.page-about .next-card:hover,
.page-about .next-card:focus-visible {
  border-color: var(--flame);
  background: rgba(18, 48, 39, 0.85);
  transform: translateY(-2px);
}
.page-about .next-card__idx {
  font-size: 13px;
  letter-spacing: 0.22em;
  color: var(--cyan-dim);
  font-variant-numeric: tabular-nums;
}
.page-about .next-card__name {
  font-size: 18px;
  font-weight: 700;
  color: var(--white);
}
.page-about .next-card__desc {
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--mist);
}
.page-about .next-card:hover .next-card__name {
  color: var(--cyan);
}

/* ---------- 响应式 ---------- */
@media (min-width: 600px) {
  .page-about .stage__facts {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .page-about .stage__matrix {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .page-about .habit-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .about-next__grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 760px) {
  .page-about .about-hero__stats {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .stage__inner {
    grid-template-columns: 118px minmax(0, 1fr);
    gap: 30px;
  }
  .page-about .stage__marks {
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
    padding-top: 4px;
  }
  .page-about .about-paper__grid {
    grid-template-columns: minmax(0, 1fr) minmax(240px, 0.62fr);
    align-items: start;
  }
  .page-about .team-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .page-about .about-sources__head {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    align-items: end;
    gap: 40px;
  }
  .page-about .habit-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 980px) {
  .page-about .about-hero__inner {
    grid-template-columns: minmax(0, 1.4fr) minmax(268px, 0.6fr);
    align-items: end;
    gap: clamp(40px, 5vw, 76px);
  }
  .page-about .about-timeline__grid {
    grid-template-columns: minmax(230px, 292px) minmax(0, 1fr);
    gap: clamp(44px, 6vw, 88px);
    align-items: start;
  }
  .page-about .source-item {
    grid-template-columns: 64px minmax(0, 1fr);
    gap: 22px;
    padding: 24px 6px;
  }
}

@media (min-width: 1180px) {
  .page-about .stage__inner {
    grid-template-columns: 142px minmax(0, 1fr);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .stage::before,
  .page-about .team-card,
  .page-about .team-card__bubble,
  .page-about .matrix-chip,
  .page-about .habit-card,
  .page-about .next-card,
  .page-about .source-item {
    transition-duration: 0.001ms;
  }
  .page-about .team-card:hover,
  .page-about .habit-card:hover,
  .page-about .matrix-chip:hover,
  .page-about .next-card:hover {
    transform: none;
  }
}
</main>