.page-about {
  --about-rail-w: 208px;
  --about-gap: clamp(28px, 4vw, 64px);
  --about-rule: 1px solid rgba(61, 86, 72, 0.55);
  background:
    radial-gradient(1200px 600px at 85% -5%, rgba(198, 255, 77, 0.06), transparent 60%),
    linear-gradient(180deg, var(--night-950) 0%, var(--night-800) 55%, var(--night-950) 100%);
  color: var(--bone-100);
  overflow-x: hidden;
}

/* ---------- 首屏 ---------- */
.page-about .about-lede {
  padding: clamp(32px, 6vw, 72px) 0 clamp(36px, 6vw, 64px);
  border-bottom: var(--about-rule);
}

.page-about .about-lede__kicker {
  margin: 18px 0 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--lime-400);
}

.page-about .about-lede__title {
  margin: 0 0 20px;
  max-width: 16em;
  font-family: var(--font-title);
  font-size: clamp(34px, 6.2vw, 72px);
  font-weight: 800;
  line-height: 1.02;
  letter-spacing: -0.02em;
  color: var(--bone-100);
}

.page-about .about-lede__text {
  max-width: 42em;
  margin: 0 0 32px;
  font-size: 16px;
  line-height: 1.78;
  color: var(--stone-300);
}

.page-about .about-lede__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px 20px;
  margin: 0;
  padding: 22px 0 0;
  list-style: none;
  border-top: var(--about-rule);
}

.page-about .about-lede__facts li {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.page-about .about-lede__facts span:last-child {
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--stone-300);
}

.page-about .about-num {
  font-family: var(--font-mono);
  font-size: 28px;
  font-weight: 700;
  line-height: 1;
  color: var(--lime-400);
}

/* ---------- 双栏：索引 + 档案册 ---------- */
.page-about .about-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--about-gap);
  padding-top: clamp(32px, 5vw, 64px);
  padding-bottom: clamp(48px, 8vw, 100px);
}

.page-about .about-index {
  display: none;
}

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

/* ---------- 章节 ---------- */
.page-about .about-chapter {
  padding-bottom: clamp(40px, 6vw, 72px);
  margin-bottom: clamp(40px, 6vw, 72px);
  border-bottom: var(--about-rule);
  scroll-margin-top: 96px;
}

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

.page-about .about-chapter__head {
  display: grid;
  gap: 6px;
  margin-bottom: 24px;
}

.page-about .about-chapter__num {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.18em;
  color: var(--clay-400);
}

.page-about .about-chapter__title {
  margin: 0;
  max-width: 22em;
  font-family: var(--font-title);
  font-size: clamp(24px, 3.4vw, 40px);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.015em;
  color: var(--bone-100);
}

.page-about .about-chapter__body > p {
  max-width: 40em;
  margin: 0 0 18px;
  font-size: 16px;
  line-height: 1.8;
  color: var(--stone-300);
}

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

/* ---------- 数据条 ---------- */
.page-about .about-strip {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin-top: 28px;
  background: rgba(61, 86, 72, 0.5);
  border: 1px solid rgba(61, 86, 72, 0.5);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .about-strip__cell {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 18px 16px;
  background: var(--moss-700);
}

.page-about .about-strip__num {
  font-family: var(--font-mono);
  font-size: 26px;
  font-weight: 700;
  line-height: 1;
  color: var(--lime-400);
}

.page-about .about-strip__label {
  font-size: 13px;
  line-height: 1.5;
  color: var(--stone-300);
}

/* ---------- 迭代轨道 ---------- */
.page-about .about-milestone-layout {
  display: grid;
  gap: 32px;
}

.page-about .about-track {
  position: relative;
  margin: 0;
  padding: 0 0 0 26px;
  list-style: none;
}

.page-about .about-track::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 6px;
  bottom: 6px;
  width: 1px;
  background: linear-gradient(180deg, var(--clay-400), rgba(182, 124, 78, 0.15));
}

.page-about .about-node {
  position: relative;
  padding: 0 0 24px;
}

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

.page-about .about-node::before {
  content: "";
  position: absolute;
  left: -26px;
  top: 8px;
  width: 11px;
  height: 11px;
  border-radius: 2px;
  background: var(--clay-400);
  border: 1px solid var(--night-950);
}

.page-about .about-node--clay::before {
  background: var(--clay-400);
}

.page-about .about-node--new::before {
  background: var(--lime-400);
  border-radius: 50%;
  box-shadow: 0 0 0 4px rgba(198, 255, 77, 0.14);
}

.page-about .about-node__year {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--lime-400);
}

.page-about .about-node__title {
  margin: 4px 0 8px;
  font-family: var(--font-title);
  font-size: 20px;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--bone-100);
}

.page-about .about-node__desc {
  margin: 0;
  max-width: 38em;
  font-size: 15px;
  line-height: 1.75;
  color: var(--stone-300);
}

.page-about .about-node__extra {
  margin: 10px 0 0;
  display: inline-block;
  padding: 4px 10px;
  border: 1px dashed rgba(198, 255, 77, 0.4);
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--lime-400);
  opacity: 0.55;
  transition: opacity 180ms var(--ease), border-color 180ms var(--ease);
}

.page-about .about-node:hover .about-node__extra,
.page-about .about-node:focus-within .about-node__extra {
  opacity: 1;
  border-color: var(--lime-400);
}

/* ---------- 图片容器补充 ---------- */
.page-about .about-figure {
  margin: 26px 0 0;
}

.page-about .about-figure .media-frame {
  overflow: hidden;
  border-radius: var(--radius);
  background: var(--moss-700);
}

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

.page-about .about-figure figcaption {
  margin-top: 10px;
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--stone-300);
}

/* ---------- 团队 ---------- */
.page-about .about-team-layout {
  display: grid;
  gap: 28px;
}

.page-about .about-roles {
  display: grid;
  gap: 20px;
  margin-top: 22px;
}

.page-about .about-role__head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 8px;
}

.page-about .about-role__name {
  font-family: var(--font-title);
  font-size: 18px;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--bone-100);
}

.page-about .about-role__count {
  font-family: var(--font-mono);
  font-size: 15px;
  color: var(--lime-400);
}

.page-about .about-role__bar {
  position: relative;
  height: 6px;
  border-radius: 4px;
  background: rgba(61, 86, 72, 0.55);
  overflow: hidden;
}

.page-about .about-role__bar::after {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: var(--w, 25%);
  border-radius: 4px;
  background: linear-gradient(90deg, var(--lime-400), rgba(198, 255, 77, 0.45));
  transition: width 200ms var(--ease);
}

.page-about .about-role:hover .about-role__bar::after,
.page-about .about-role:focus-within .about-role__bar::after {
  background: linear-gradient(90deg, var(--lime-400), var(--clay-400));
}

.page-about .about-role__desc {
  margin: 10px 0 0;
  max-width: 36em;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--stone-300);
}

/* ---------- 合作 ---------- */
.page-about .about-partner-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
  margin-top: 24px;
}

.page-about .about-partner {
  position: relative;
  padding: 22px 20px 20px;
  border-radius: var(--radius-lg);
  transition: transform 180ms var(--ease), box-shadow 180ms var(--ease);
}

.page-about .about-partner:hover,
.page-about .about-partner:focus-within {
  transform: translateY(-3px);
  box-shadow: 0 14px 32px rgba(0, 0, 0, 0.35);
}

.page-about .about-partner__num {
  margin: 14px 0 2px;
  font-family: var(--font-mono);
  font-size: 40px;
  font-weight: 700;
  line-height: 1;
  color: var(--lime-400);
}

.page-about .about-partner .card__title {
  font-family: var(--font-title);
  font-size: 20px;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.page-about .about-partner .card__body p {
  margin: 12px 0 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--stone-300);
}

.page-about .about-partner--assoc {
  border-top: 2px solid var(--lime-400);
}

.page-about .about-partner--youth {
  border-top: 2px solid var(--clay-400);
}

.page-about .about-partner--media {
  border-top: 2px solid var(--stone-500);
}

/* ---------- 覆盖刻度 ---------- */
.page-about .about-scale {
  display: flex;
  align-items: flex-end;
  gap: 6px;
  margin-top: 26px;
  padding: 18px 14px 10px;
  border-bottom: 1px solid rgba(61, 86, 72, 0.6);
  border-radius: var(--radius) var(--radius) 0 0;
  background: rgba(18, 32, 26, 0.7);
}

.page-about .about-scale__tick {
  flex: 1 1 0;
  min-width: 4px;
  height: 18px;
  border-radius: 2px 2px 0 0;
  background: rgba(61, 86, 72, 0.9);
}

.page-about .about-scale__tick--key {
  height: 34px;
  background: var(--lime-400);
}

.page-about .about-scale__caption {
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 12px 0 0;
  font-size: 12.5px;
  letter-spacing: 0.03em;
  color: var(--stone-300);
}

.page-about .about-scale__dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--lime-400);
}

/* ---------- 选择理由 ---------- */
.page-about .about-why {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: rgba(61, 86, 72, 0.45);
  border: 1px solid rgba(61, 86, 72, 0.45);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .about-why__item {
  padding: 22px 20px;
  background: var(--moss-700);
}

.page-about .about-why__num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--clay-400);
}

.page-about .about-why__item h3 {
  margin: 8px 0 10px;
  font-family: var(--font-title);
  font-size: 19px;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--bone-100);
}

.page-about .about-why__item p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--stone-300);
}

.page-about .about-cta {
  margin-top: 32px;
  padding: 26px 22px;
  border-left: 2px solid var(--lime-400);
  border-radius: 0 var(--radius) var(--radius) 0;
  background: rgba(18, 32, 26, 0.85);
}

.page-about .about-cta__text {
  max-width: 40em;
  margin: 0 0 18px;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--stone-300);
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .about-lede__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-strip {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

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

@media (min-width: 960px) {
  .page-about .about-shell {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .about-index {
    display: block;
    position: sticky;
    top: 104px;
    padding-right: 20px;
    border-right: var(--about-rule);
  }

  .page-about .about-index__label {
    margin: 0 0 16px;
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: var(--stone-300);
  }

  .page-about .about-index__list {
    margin: 0;
    padding: 0;
    list-style: none;
  }

  .page-about .about-index__list li + li {
    margin-top: 2px;
  }

  .page-about .about-index__link {
    display: flex;
    align-items: baseline;
    gap: 10px;
    padding: 8px 10px 8px 0;
    font-size: 14.5px;
    color: var(--stone-300);
    text-decoration: none;
    border-left: 2px solid transparent;
    padding-left: 12px;
    transition: color 160ms var(--ease), border-color 160ms var(--ease);
  }

  .page-about .about-index__link:hover,
  .page-about .about-index__link:focus-visible {
    color: var(--bone-100);
    border-left-color: rgba(198, 255, 77, 0.6);
    outline: none;
  }

  .page-about .about-index__link.is-active {
    color: var(--lime-400);
    border-left-color: var(--lime-400);
  }

  .page-about .about-index__num {
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: 0.1em;
    color: var(--stone-300);
  }

  .page-about .about-index__link.is-active .about-index__num {
    color: var(--lime-400);
  }

  .page-about .about-milestone-layout {
    grid-template-columns: minmax(0, 1fr) 300px;
    gap: 40px;
    align-items: start;
  }

  .page-about .about-milestone-layout .about-figure {
    margin-top: 6px;
    position: sticky;
    top: 104px;
  }

  .page-about .about-team-layout {
    grid-template-columns: minmax(0, 1fr) 300px;
    gap: 40px;
    align-items: start;
  }

  .page-about .about-team-layout .about-figure {
    margin-top: 4px;
  }
}

@media (min-width: 1200px) {
  .page-about .about-why {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

.page-about {
  --w: 1rem;
}