.page-about {
  --about-index-w: 214px;
  --about-gap: clamp(24px, 4vw, 60px);
  --about-sticky-top: 108px;
  position: relative;
  background:
    radial-gradient(circle at 16% 2%, rgba(51, 242, 192, 0.10), transparent 42%),
    radial-gradient(circle at 92% 26%, rgba(255, 179, 92, 0.06), transparent 38%),
    var(--c-bg);
  color: var(--c-text);
  overflow-x: hidden;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding: clamp(18px, 4vw, 40px) 0 clamp(30px, 6vw, 68px);
  border-bottom: var(--bw) solid var(--c-line);
}

.page-about .about-hero .breadcrumb {
  margin-bottom: clamp(18px, 3vw, 30px);
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(26px, 5vw, 48px);
  align-items: start;
}

.page-about .about-hero__lead h1 {
  margin: 10px 0 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(30px, 7.2vw, 60px);
  line-height: 1.1;
  letter-spacing: -0.01em;
  color: var(--c-paper);
  text-wrap: balance;
}

.page-about .about-hero__lead .lede {
  margin: 18px 0 0;
  max-width: 62ch;
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.78;
  color: var(--c-text);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

.page-about .about-hero__actions .btn {
  flex: 1 1 168px;
  justify-content: center;
  text-align: center;
}

.page-about .about-hero__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
}

.page-about .stat-block {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 14px 14px 16px;
  border: var(--bw) solid var(--c-line);
  background: var(--c-panel);
  box-shadow: var(--shadow-hard);
}

.page-about .stat-block--accent {
  border-color: var(--c-cyan);
  box-shadow: var(--shadow-lift);
}

.page-about .stat-block__num {
  font-family: var(--font-mono);
  font-size: clamp(26px, 5.6vw, 38px);
  font-weight: 700;
  line-height: 1;
  color: var(--c-cyan);
  letter-spacing: -0.02em;
}

.page-about .stat-block--accent .stat-block__num {
  color: var(--c-cyan-hi);
}

.page-about .stat-block__unit {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--c-amber);
  letter-spacing: 0.06em;
}

.page-about .stat-block__label {
  font-size: 12px;
  line-height: 1.5;
  color: var(--c-muted);
}

/* ---------- 主体骨架 ---------- */
.page-about .about-layout {
  display: grid;
  gap: var(--about-gap);
  padding-top: clamp(28px, 6vw, 72px);
  padding-bottom: clamp(40px, 8vw, 96px);
}

/* 移动端：横向滚动的章节条 */
.page-about .about-index {
  border: var(--bw) solid var(--c-line);
  background: var(--c-panel);
  padding: 10px 12px 8px;
  box-shadow: var(--shadow-hard);
}

.page-about .about-index__title {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--c-muted);
}

.page-about .about-index__list {
  display: flex;
  gap: 6px;
  margin: 0;
  padding: 0 0 4px;
  list-style: none;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: thin;
  scrollbar-color: var(--c-line) transparent;
}

.page-about .about-index__item {
  flex: 0 0 auto;
}

.page-about .about-index__link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 7px 10px;
  border: 1px solid var(--c-line);
  background: var(--c-void);
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.02em;
  color: var(--c-text);
  text-decoration: none;
  white-space: nowrap;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease), background-color 0.18s var(--ease);
}

.page-about .about-index__link:hover {
  color: var(--c-cyan-hi);
  border-color: var(--c-cyan);
}

.page-about .about-index__link.is-active {
  background: var(--c-cyan);
  border-color: var(--c-cyan);
  color: var(--c-void);
}

.page-about .about-index__no {
  font-size: 10px;
  opacity: 0.7;
}

/* ---------- 章节 ---------- */
.page-about .about-main {
  min-width: 0;
}

.page-about .chapter {
  position: relative;
  padding-block: clamp(26px, 5vw, 52px);
  border-top: var(--bw) solid var(--c-line);
}

.page-about .chapter:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .chapter--versions {
  background: linear-gradient(180deg, rgba(51, 242, 192, 0.05), transparent 62%);
}

.page-about .chapter--return {
  background: linear-gradient(180deg, rgba(255, 179, 92, 0.06), transparent 60%);
}

.page-about .chapter__head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 12px 14px;
  align-items: baseline;
  margin-bottom: clamp(18px, 3.4vw, 30px);
}

.page-about .chapter__no {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(26px, 5.4vw, 44px);
  font-weight: 700;
  line-height: 0.9;
  color: var(--c-cyan);
  letter-spacing: -0.03em;
}

.page-about .chapter--return .chapter__no {
  color: var(--c-amber);
}

.page-about .chapter__title {
  margin: 0;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: clamp(21px, 3.6vw, 33px);
  line-height: 1.3;
  color: var(--c-paper);
  text-wrap: balance;
}

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

.page-about .chapter__body > p {
  margin: 0 0 18px;
  max-width: 68ch;
  font-size: clamp(15px, 1.55vw, 16.5px);
  line-height: 1.8;
}

.page-about .chapter__body a {
  color: var(--c-cyan-hi);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-thickness: 1px;
}

.page-about .chapter__body a:hover {
  color: var(--c-amber);
}

/* ---------- 立柱卡片 ---------- */
.page-about .pillar-list {
  display: grid;
  gap: 12px;
  margin: 26px 0 0;
}

.page-about .pillar {
  padding: 16px 16px 18px;
  border: var(--bw) solid var(--c-line);
  background: var(--c-panel);
  box-shadow: var(--shadow-hard);
  transition: border-color 0.2s var(--ease), transform 0.2s var(--ease);
}

.page-about .pillar:hover {
  border-color: var(--c-cyan);
  transform: translate(-2px, -2px);
}

.page-about .pillar__k {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--c-amber);
}

.page-about .pillar__t {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(17px, 2vw, 19px);
  line-height: 1.35;
  color: var(--c-paper);
}

.page-about .pillar__d {
  margin: 0;
  font-size: 14px;
  line-height: 1.72;
  color: var(--c-text);
}

.page-about .chapter__quote {
  margin: 30px 0 0;
  padding: 18px 0 18px 18px;
  border-left: 3px solid var(--c-cyan);
  font-family: var(--font-serif);
  font-size: clamp(20px, 3.4vw, 28px);
  font-weight: 700;
  line-height: 1.4;
  color: var(--c-cyan-hi);
}

/* ---------- 图片 ---------- */
.page-about .figure {
  margin: 24px 0 0;
}

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

.page-about .figure__caption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  line-height: 1.6;
  color: var(--c-muted);
}

/* ---------- 时间轴 ---------- */
.page-about .timeline {
  position: relative;
  margin-top: 28px;
  padding-left: 22px;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 6px;
  bottom: 6px;
  width: 2px;
  background: linear-gradient(180deg, var(--c-cyan), var(--c-line) 70%);
}

.page-about .tl-node {
  position: relative;
  margin-bottom: 10px;
  border: var(--bw) solid var(--c-line);
  background: var(--c-panel);
}

.page-about .tl-node::before {
  content: "";
  position: absolute;
  left: -22px;
  top: 18px;
  width: 9px;
  height: 9px;
  background: var(--c-void);
  border: 2px solid var(--c-cyan);
  box-shadow: 0 0 0 3px rgba(51, 242, 192, 0.14);
}

.page-about .tl-node[open] {
  border-color: var(--c-cyan);
  box-shadow: var(--shadow-hard);
}

.page-about .tl-node > summary {
  list-style: none;
  cursor: pointer;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px 10px;
  padding: 13px 14px;
}

.page-about .tl-node > summary::-webkit-details-marker {
  display: none;
}

.page-about .tl-node__ver {
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--c-cyan);
}

.page-about .tl-node[open] .tl-node__ver {
  color: var(--c-cyan-hi);
}

.page-about .tl-node__name {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 15.5px;
  color: var(--c-paper);
}

.page-about .tl-node__meta {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--c-muted);
}

.page-about .tl-node__toggle {
  position: relative;
  margin-left: auto;
  width: 14px;
  height: 14px;
  flex: 0 0 14px;
  align-self: center;
}

.page-about .tl-node__toggle::before,
.page-about .tl-node__toggle::after {
  content: "";
  position: absolute;
  background: var(--c-amber);
  transition: transform 0.2s var(--ease);
}

.page-about .tl-node__toggle::before {
  left: 0;
  top: 6px;
  width: 14px;
  height: 2px;
}

.page-about .tl-node__toggle::after {
  left: 6px;
  top: 0;
  width: 2px;
  height: 14px;
}

.page-about .tl-node[open] .tl-node__toggle::after {
  transform: scaleY(0);
}

.page-about .tl-node__panel {
  padding: 0 14px 16px;
  border-top: 1px solid var(--c-line);
}

.page-about .tl-node__panel > p {
  margin: 14px 0 0;
  font-size: 14.5px;
  line-height: 1.75;
}

.page-about .tl-node__list {
  margin: 12px 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 6px;
}

.page-about .tl-node__list li {
  position: relative;
  padding-left: 15px;
  font-size: 13.5px;
  line-height: 1.65;
  color: var(--c-text);
}

.page-about .tl-node__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 8px;
  width: 5px;
  height: 5px;
  background: var(--c-cyan);
}

.page-about .tl-node__more {
  margin: 14px 0 0;
  font-family: var(--font-mono);
  font-size: 12px;
}

.page-about .tl-node__more a {
  color: var(--c-amber);
  text-decoration: none;
  border-bottom: 1px solid currentColor;
}

/* ---------- 回访观察 ---------- */
.page-about .return-grid {
  display: grid;
  gap: 12px;
  margin: 26px 0 0;
}

.page-about .return-highlight {
  padding: 18px 18px 20px;
  border: var(--bw) solid var(--c-cyan);
  background: var(--c-panel);
  box-shadow: var(--shadow-lift);
}

.page-about .return-highlight--alt {
  border-color: var(--c-amber);
  box-shadow: var(--shadow-hard);
}

.page-about .return-highlight__label {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--c-muted);
}

.page-about .return-highlight__num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(34px, 8vw, 56px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--c-cyan);
}

.page-about .return-highlight--alt .return-highlight__num {
  color: var(--c-amber);
}

.page-about .return-highlight__pct {
  font-size: 0.56em;
  margin-left: 2px;
}

.page-about .return-highlight__text {
  margin: 10px 0 0;
  font-size: 13.5px;
  line-height: 1.6;
  color: var(--c-text);
}

.page-about .path-map {
  display: grid;
  gap: 10px;
  margin: 26px 0 20px;
}

.page-about .path-map__item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 4px 12px;
  padding: 14px 15px;
  border: var(--bw) solid var(--c-line);
  background: var(--c-panel);
  transition: border-color 0.2s var(--ease), box-shadow 0.2s var(--ease);
}

.page-about .path-map__item:hover,
.page-about .path-map__item:focus {
  border-color: var(--c-cyan);
  box-shadow: var(--shadow-hard);
  outline: none;
}

.page-about .path-map__index {
  grid-row: span 2;
  align-self: start;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  color: var(--c-amber);
  letter-spacing: 0.08em;
  padding-top: 2px;
}

.page-about .path-map__name {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 15px;
  color: var(--c-paper);
}

.page-about .path-map__tip {
  grid-column: 2;
  font-size: 13px;
  line-height: 1.65;
  color: var(--c-text);
  opacity: 1;
  transition: opacity 0.22s var(--ease), color 0.22s var(--ease);
}

/* ---------- 团队 ---------- */
.page-about .team-grid {
  display: grid;
  gap: 12px;
  margin-top: 26px;
}

.page-about .team-card {
  position: relative;
  padding: 18px 16px 20px;
  border: var(--bw) solid var(--c-line);
  background: var(--c-panel);
  box-shadow: var(--shadow-hard);
  transition: border-color 0.2s var(--ease), transform 0.2s var(--ease);
}

.page-about .team-card:hover {
  border-color: var(--c-amber);
  transform: translate(-2px, -2px);
}

.page-about .team-card__key {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.22em;
  color: var(--c-cyan);
}

.page-about .team-card__title {
  margin: 0 0 8px;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: clamp(17px, 2vw, 20px);
  line-height: 1.35;
  color: var(--c-paper);
}

.page-about .team-card__desc {
  margin: 0;
  font-size: 13.8px;
  line-height: 1.75;
  color: var(--c-text);
}

/* ---------- 生态 ---------- */
.page-about .eco-list {
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
  border-top: var(--bw) solid var(--c-line);
}

.page-about .eco-list__row {
  display: grid;
  grid-template-columns: minmax(72px, auto) minmax(0, 1fr);
  gap: 6px 18px;
  padding: 18px 0;
  border-bottom: 1px solid var(--c-line);
}

.page-about .eco-list__num {
  font-family: var(--font-mono);
  font-size: clamp(28px, 6vw, 42px);
  font-weight: 700;
  line-height: 1;
  color: var(--c-cyan);
  letter-spacing: -0.03em;
}

.page-about .eco-list__plus {
  color: var(--c-amber);
  font-size: 0.7em;
  margin-left: 1px;
}

.page-about .eco-list__body {
  min-width: 0;
}

.page-about .eco-list__title {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(15px, 1.9vw, 17px);
  line-height: 1.4;
  color: var(--c-paper);
}

.page-about .eco-list__desc {
  margin: 0;
  font-size: 13.8px;
  line-height: 1.72;
  color: var(--c-text);
}

/* ---------- 联系 ---------- */
.page-about .cta-panel {
  padding: clamp(20px, 3.4vw, 32px);
  border: var(--bw) solid var(--c-cyan);
  background:
    linear-gradient(135deg, rgba(51, 242, 192, 0.10), transparent 62%),
    var(--c-panel);
  box-shadow: var(--shadow-lift);
}

.page-about .cta-panel > p {
  margin: 0 0 18px;
  max-width: 64ch;
  font-size: clamp(14.5px, 1.6vw, 16px);
  line-height: 1.78;
}

.page-about .cta-panel__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.page-about .cta-panel__actions .btn {
  flex: 1 1 168px;
  justify-content: center;
  text-align: center;
}

.page-about .cta-panel__note {
  margin: 18px 0 0 !important;
  font-family: var(--font-mono);
  font-size: 12px !important;
  line-height: 1.7 !important;
  color: var(--c-muted);
}

.page-about .cta-panel__note a {
  color: var(--c-amber);
}

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

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

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

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

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

/* ---------- 桌面 ---------- */
@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    gap: clamp(32px, 4vw, 64px);
  }

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

  .page-about .about-hero__actions .btn,
  .page-about .cta-panel__actions .btn {
    flex: 0 0 auto;
  }

  .page-about .about-layout {
    grid-template-columns: var(--about-index-w) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .about-index {
    position: sticky;
    top: var(--about-sticky-top);
    padding: 16px 14px;
  }

  .page-about .about-index__list {
    flex-direction: column;
    gap: 4px;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .about-index__item {
    flex: 0 1 auto;
  }

  .page-about .about-index__link {
    display: flex;
    width: 100%;
    padding: 9px 10px;
    font-size: 12.5px;
    border-color: transparent;
    background: transparent;
    white-space: normal;
  }

  .page-about .about-index__link:hover {
    background: var(--c-void);
  }

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

  .page-about .pillar {
    display: flex;
    flex-direction: column;
  }

  .page-about .pillar__d {
    margin-top: auto;
  }

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

  /* 桌面端：路径提示悬停/聚焦时出现 */
  .page-about .path-map {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 0;
  }

  .page-about .path-map__item {
    border-right-width: 0;
  }

  .page-about .path-map__item:last-child {
    border-right-width: var(--bw);
  }

  .page-about .path-map__item:hover,
  .page-about .path-map__item:focus {
    transform: translateY(-4px);
  }

  .page-about .path-map__tip {
    opacity: 0;
    color: var(--c-muted);
  }

  .page-about .path-map__item:hover .path-map__tip,
  .page-about .path-map__item:focus .path-map__tip,
  .page-about .path-map__item:focus-within .path-map__tip {
    opacity: 1;
    color: var(--c-text);
  }

  .page-about .eco-list__row {
    grid-template-columns: 130px minmax(0, 1fr);
    gap: 8px 28px;
    padding: 22px 0;
  }
}

@media (min-width: 1120px) {
  .page-about .chapter__head {
    gap: 14px 22px;
  }

  .page-about .return-grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    gap: 16px;
  }
}

/* ---------- 动效偏好 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .pillar,
  .page-about .team-card,
  .page-about .path-map__item,
  .page-about .path-map__tip {
    transition: none;
  }

  .page-about .path-map__item:hover,
  .page-about .path-map__item:focus,
  .page-about .pillar:hover,
  .page-about .team-card:hover {
    transform: none;
  }
}
<<<END>>>