.page-about {
  background: var(--cream);
  color: var(--ink);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  background: var(--deep);
  color: var(--on-dark);
  padding: 26px 0 42px;
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  right: -90px;
  top: -70px;
  width: 300px;
  height: 300px;
  border: var(--bd) solid rgba(216, 243, 74, .26);
  border-radius: 50%;
  pointer-events: none;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  left: -70px;
  bottom: -140px;
  width: 280px;
  height: 280px;
  background: linear-gradient(135deg, rgba(47, 168, 79, .42), rgba(53, 196, 192, .10));
  transform: rotate(28deg);
  pointer-events: none;
}

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

.page-about .about-hero .breadcrumb {
  margin: 0 0 22px;
  font-size: 12px;
}

.page-about .about-hero .breadcrumb ol,
.page-about .about-hero .breadcrumb li {
  color: var(--on-dark-soft);
}

.page-about .about-hero .breadcrumb a {
  color: var(--on-dark-soft);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--ease), border-color var(--ease);
}

.page-about .about-hero .breadcrumb a:hover,
.page-about .about-hero .breadcrumb a:focus-visible {
  color: var(--lime);
  border-bottom-color: var(--lime);
}

.page-about .about-hero .kicker--dark {
  margin: 0 0 14px;
}

.page-about .about-hero h1 {
  margin: 0 0 18px;
  font-size: clamp(28px, 6.4vw, 52px);
  line-height: 1.16;
  letter-spacing: -.01em;
  font-weight: 900;
  color: var(--cream);
  max-width: 17em;
}

.page-about .about-lede {
  margin: 0;
  max-width: 46em;
  font-size: 15px;
  line-height: 1.82;
  color: var(--on-dark);
}

.page-about .hero-facts {
  list-style: none;
  margin: 30px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line-dark);
  border: var(--bd) solid var(--line-dark);
  clip-path: var(--cut-lg);
}

.page-about .hero-facts li {
  background: var(--deep-2);
  padding: 14px 16px 15px;
  display: flex;
  flex-direction: column;
  gap: 3px;
}

.page-about .fact-num {
  font-size: 26px;
  font-weight: 700;
  line-height: 1;
  color: var(--lime);
  letter-spacing: -.02em;
}

.page-about .fact-label {
  font-size: 12px;
  line-height: 1.5;
  color: var(--on-dark-soft);
}

/* ---------- 头图 ---------- */
.page-about .about-lead {
  position: relative;
  margin: 0;
  background: var(--deep);
  overflow: hidden;
}

.page-about .about-lead img {
  display: block;
  width: 100%;
  height: clamp(190px, 38vw, 430px);
  object-fit: cover;
  opacity: .78;
}

.page-about .about-lead::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg,
    rgba(11, 27, 58, .62) 0%,
    rgba(11, 27, 58, .12) 45%,
    rgba(11, 27, 58, .68) 100%);
  pointer-events: none;
}

/* ---------- 版式骨架 ---------- */
.page-about .about-layout {
  padding-top: 30px;
  padding-bottom: 54px;
}

.page-about .about-toc {
  position: sticky;
  top: var(--strip-h);
  z-index: 5;
  margin: 0 0 26px;
  padding: 10px 0 12px;
  background: rgba(247, 248, 243, .94);
  border-bottom: 1px solid var(--line);
}

.page-about .about-toc .rail-label {
  display: none;
}

.page-about .toc-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  scrollbar-width: none;
}

.page-about .toc-list::-webkit-scrollbar {
  display: none;
}

.page-about .toc-list li {
  flex: 0 0 auto;
}

.page-about .toc-list a {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 7px 13px;
  background: var(--paper);
  border: var(--bd) solid var(--line);
  clip-path: var(--cut-sm);
  color: var(--ink);
  font-size: 13px;
  text-decoration: none;
  white-space: nowrap;
  transition: background var(--ease), border-color var(--ease), color var(--ease);
}

.page-about .toc-list a:hover,
.page-about .toc-list a:focus-visible {
  background: var(--lime);
  border-color: var(--turf-deep);
  color: var(--deep);
}

.page-about .toc-num {
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--turf-deep);
}

.page-about .toc-list a:hover .toc-num,
.page-about .toc-list a:focus-visible .toc-num {
  color: var(--deep);
}

/* ---------- 章节 ---------- */
.page-about .chapter + .chapter {
  margin-top: 46px;
}

.page-about .chapter-head {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  margin-bottom: 16px;
}

.page-about .chapter-num {
  flex: 0 0 auto;
  font-size: 40px;
  line-height: .88;
  font-weight: 700;
  letter-spacing: -.03em;
  color: var(--turf-deep);
  opacity: .3;
}

.page-about .chapter-head h2 {
  margin: 0;
  font-size: clamp(21px, 4.4vw, 27px);
  line-height: 1.3;
  font-weight: 900;
  letter-spacing: -.005em;
  color: var(--ink);
}

.page-about .chapter-body > p {
  margin: 0 0 16px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-soft);
}

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

.page-about .pull {
  border-left: 3px solid var(--turf);
  padding: 6px 0 6px 16px;
  margin: 22px 0;
  font-size: 16px;
  line-height: 1.72;
  font-weight: 500;
  color: var(--ink);
}

/* ---------- 旁注 ---------- */
.page-about .aside-note {
  margin: 26px 0;
  background: var(--mint);
  border: var(--bd) solid var(--line);
  clip-path: var(--cut-lg);
}

.page-about .aside-note summary {
  list-style: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 15px 20px;
  font-size: 15px;
  font-weight: 700;
  color: var(--ink);
}

.page-about .aside-note summary::-webkit-details-marker {
  display: none;
}

.page-about .aside-note summary::before {
  content: "▸";
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--turf-deep);
  transition: transform var(--ease);
}

.page-about .aside-note details[open] summary::before {
  transform: rotate(90deg);
}

.page-about .aside-body {
  padding: 0 20px 18px;
  display: grid;
  gap: 14px;
}

.page-about .aside-body p {
  margin: 0;
  font-size: 14px;
  line-height: 1.74;
  color: var(--ink-soft);
}

/* ---------- 分工小卡 ---------- */
.page-about .duty-grid {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .duty-card {
  background: var(--paper);
  border: var(--bd) solid var(--line);
  clip-path: var(--cut-sm);
  padding: 18px 18px 20px;
  transition: transform var(--ease), box-shadow var(--ease), border-color var(--ease);
}

.page-about .duty-card:hover,
.page-about .duty-card:focus-within {
  transform: translateY(-3px);
  border-color: var(--turf);
  box-shadow: var(--shadow-panel);
}

.page-about .duty-num {
  display: block;
  font-size: 28px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--turf-deep);
  margin-bottom: 10px;
}

.page-about .duty-card h3 {
  margin: 0 0 8px;
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
}

.page-about .duty-card p {
  margin: 0;
  font-size: 14px;
  line-height: 1.72;
  color: var(--ink-soft);
}

/* ---------- 历程带 ---------- */
.page-about .journey-banner {
  position: relative;
  margin: 24px 0 20px;
  background: var(--deep);
  clip-path: var(--cut-lg);
  overflow: hidden;
}

.page-about .journey-banner img {
  display: block;
  width: 100%;
  height: clamp(140px, 24vw, 300px);
  object-fit: cover;
  opacity: .85;
}

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

.page-about .journey-node {
  background: var(--paper);
  border: var(--bd) solid var(--line);
  clip-path: var(--cut-sm);
  box-shadow: inset 4px 0 0 0 var(--turf);
}

.page-about .journey-node summary {
  list-style: none;
  cursor: pointer;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px 12px;
  padding: 16px 18px 16px 22px;
}

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

.page-about .journey-year {
  font-size: 23px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--turf-deep);
}

.page-about .journey-name {
  font-size: 15px;
  font-weight: 700;
  color: var(--ink);
}

.page-about .journey-node summary::after {
  content: "＋";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 15px;
  line-height: 1;
  color: var(--steel);
}

.page-about .journey-node[open] summary::after {
  content: "－";
  color: var(--turf-deep);
}

.page-about .journey-node p {
  margin: 0;
  padding: 0 20px 18px 22px;
  font-size: 14px;
  line-height: 1.76;
  color: var(--ink-soft);
}

/* ---------- 合作生态 ---------- */
.page-about .eco-grid {
  display: grid;
  gap: 22px;
  margin-top: 4px;
}

.page-about .eco-text p {
  margin: 0 0 16px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-soft);
}

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

.page-about .eco-media {
  margin: 0;
  background: var(--deep);
  clip-path: var(--cut-lg);
  overflow: hidden;
}

.page-about .eco-media img {
  display: block;
  width: 100%;
  height: 230px;
  object-fit: cover;
  opacity: .9;
}

/* ---------- 收尾入口 ---------- */
.page-about .about-next {
  padding-bottom: 60px;
}

.page-about .next-panel {
  background: var(--deep-2);
  padding: 28px 22px 22px;
}

.page-about .next-panel .kicker--dark {
  margin: 0;
}

.page-about .next-panel h2 {
  margin: 10px 0 18px;
  font-size: clamp(20px, 4.4vw, 25px);
  line-height: 1.32;
  font-weight: 900;
  color: var(--cream);
}

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

.page-about .next-list li + li {
  border-top: 1px solid var(--line-dark);
}

.page-about .next-list a {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 0;
  font-size: 15px;
  line-height: 1.6;
  color: var(--on-dark);
  text-decoration: none;
  transition: color var(--ease), gap var(--ease);
}

.page-about .next-list a .mono {
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--turf);
  transition: color var(--ease);
}

.page-about .next-list a:hover,
.page-about .next-list a:focus-visible {
  color: var(--lime);
  gap: 20px;
}

.page-about .next-list a:hover .mono,
.page-about .next-list a:focus-visible .mono {
  color: var(--lime);
}

/* ---------- 断点 ---------- */
@media (min-width: 620px) {
  .page-about .duty-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .aside-body {
    grid-template-columns: 1fr 1fr;
  }

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

@media (min-width: 760px) {
  .page-about .about-hero {
    padding: 34px 0 54px;
  }

  .page-about .about-lede {
    font-size: 16px;
  }

  .page-about .chapter-body > p,
  .page-about .eco-text p {
    font-size: 16.5px;
  }

  .page-about .chapter + .chapter {
    margin-top: 58px;
  }

  .page-about .next-panel {
    padding: 36px 38px 30px;
  }
}

@media (min-width: 880px) {
  .page-about .eco-grid {
    grid-template-columns: minmax(0, 1fr) 340px;
    align-items: start;
    gap: 32px;
  }

  .page-about .eco-media img {
    height: 260px;
  }
}

@media (min-width: 960px) {
  .page-about .about-layout {
    display: grid;
    grid-template-columns: 186px minmax(0, 1fr);
    gap: 56px;
    align-items: start;
    padding-top: 46px;
    padding-bottom: 64px;
  }

  .page-about .about-toc {
    position: sticky;
    top: 34px;
    margin: 0;
    padding: 0;
    background: transparent;
    border-bottom: 0;
    z-index: 1;
  }

  .page-about .about-toc .rail-label {
    display: block;
    margin: 0 0 14px;
    color: var(--steel);
  }

  .page-about .toc-list {
    display: block;
    overflow: visible;
    border-left: 2px solid var(--line);
  }

  .page-about .toc-list li {
    display: block;
  }

  .page-about .toc-list a {
    display: flex;
    border: 0;
    clip-path: none;
    background: transparent;
    padding: 8px 0 8px 14px;
    margin-left: -2px;
    border-left: 2px solid transparent;
    font-size: 13.5px;
    line-height: 1.55;
    white-space: normal;
  }

  .page-about .toc-list a:hover,
  .page-about .toc-list a:focus-visible {
    background: transparent;
    color: var(--turf-deep);
    border-left-color: var(--turf);
  }

  .page-about .toc-list a:hover .toc-num,
  .page-about .toc-list a:focus-visible .toc-num {
    color: var(--turf-deep);
  }

  .page-about .chapter + .chapter {
    margin-top: 68px;
  }

  .page-about .chapter-num {
    font-size: 46px;
  }
}

@media (min-width: 1120px) {
  .page-about .about-layout {
    grid-template-columns: 210px minmax(0, 1fr);
    gap: 68px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    transition-duration: 0ms !important;
    animation-duration: 0ms !important;
  }
}