.page-about {
  --about-rail-w: 300px;
  background: var(--paper);
  color: var(--text);
  padding-block: clamp(18px, 3vw, 32px) clamp(48px, 8vw, 96px);
}

.page-about .breadcrumbs {
  padding-block: 0 clamp(16px, 3vw, 28px);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  display: grid;
  gap: 16px;
  padding-bottom: clamp(26px, 5vw, 46px);
  border-bottom: 1px solid var(--hairline);
}

.page-about .about-hero .eyebrow {
  margin: 0;
  color: var(--c-green);
  letter-spacing: 0.16em;
}

.page-about .about-hero h1 {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(30px, 5.2vw, 58px);
  line-height: 1.14;
  letter-spacing: 0.015em;
  max-width: 20ch;
  color: var(--c-night);
}

.page-about .about-hero .lede {
  margin: 0;
  max-width: 62ch;
  font-size: clamp(16px, 1.6vw, 19px);
  line-height: 1.8;
  color: var(--text-muted);
}

.page-about .hero-facts {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 4px;
}

/* ---------- 分屏骨架 ---------- */
.page-about .about-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(30px, 5vw, 56px);
  padding-top: clamp(26px, 5vw, 48px);
}

/* ---------- 左侧窄栏 ---------- */
.page-about .about-rail {
  display: grid;
  gap: 22px;
  align-content: start;
  border-top: 2px solid var(--brand);
  padding-top: 18px;
  min-width: 0;
}

.page-about .rail-lead {
  margin: 0;
  font-family: var(--font-serif);
  font-size: 16px;
  line-height: 1.85;
  color: var(--c-green-deep);
}

.page-about .rail-stats {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px 16px;
}

.page-about .rail-stat {
  display: grid;
  gap: 4px;
  padding-left: 10px;
  border-left: 2px solid var(--hairline);
  min-width: 0;
}

.page-about .rail-stat .stat-num {
  font-family: var(--font-mono);
  font-size: clamp(22px, 3.4vw, 28px);
  line-height: 1.1;
  letter-spacing: -0.01em;
  color: var(--c-green);
}

.page-about .rail-plus {
  font-size: 0.62em;
  color: var(--accent);
  padding-left: 1px;
}

.page-about .rail-stat .stat-label {
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--text-muted);
}

.page-about .rail-nav {
  display: grid;
  gap: 2px;
  border-top: 1px solid var(--hairline);
  padding-top: 12px;
}

.page-about .rail-nav a {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 9px 8px 9px 10px;
  border-left: 2px solid transparent;
  color: var(--text-muted);
  text-decoration: none;
  font-size: 14px;
  line-height: 1.5;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease),
    background-color var(--dur) var(--ease);
}

.page-about .rail-nav a .num {
  font-size: 12px;
  color: var(--c-blue);
}

.page-about .rail-nav a:hover,
.page-about .rail-nav a:focus-visible {
  color: var(--c-green-deep);
  border-left-color: var(--accent);
  background: var(--surface);
}

.page-about .rail-nav a:hover .num,
.page-about .rail-nav a:focus-visible .num {
  color: var(--accent);
}

/* ---------- 右侧章节流 ---------- */
.page-about .about-flow {
  display: grid;
  gap: 0;
  min-width: 0;
}

.page-about .about-chapter {
  padding-block: clamp(26px, 4vw, 40px);
  border-top: 1px solid var(--hairline);
  scroll-margin-top: 96px;
}

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

.page-about .chapter-head {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 6px;
  margin-bottom: 18px;
}

.page-about .chapter-head .section-num {
  font-family: var(--font-serif);
  font-size: clamp(38px, 6.4vw, 66px);
  line-height: 0.9;
  color: var(--c-green);
  opacity: 0.32;
  letter-spacing: 0.02em;
}

.page-about .chapter-head h2 {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(21px, 3vw, 31px);
  line-height: 1.32;
  letter-spacing: 0.01em;
  color: var(--c-night);
  max-width: 24ch;
}

.page-about .chapter-body p {
  margin: 0 0 18px;
  max-width: 66ch;
  font-size: 16px;
  line-height: 1.85;
}

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

/* ---------- 图片 ---------- */
.page-about .media-frame {
  margin: 22px 0;
  background: linear-gradient(150deg, var(--c-night) 0%, var(--c-green-deep) 58%, var(--c-blue) 100%);
  overflow: hidden;
  border: 1px solid var(--hairline);
}

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

.page-about .media-caption {
  margin: 8px 0 0;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.7;
  letter-spacing: 0.02em;
  color: var(--text-muted);
}

.page-about .chapter-body figure + p {
  margin-top: 20px;
}

/* ---------- 团队数字 ---------- */
.page-about .team-grid {
  list-style: none;
  margin: 0 0 24px;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
}

.page-about .team-stat {
  display: grid;
  gap: 6px;
  padding: 16px 14px;
  background: var(--surface);
  border: 1px solid var(--hairline);
  border-left: 3px solid var(--c-mint);
  transition: border-color var(--dur) var(--ease), transform var(--dur) var(--ease),
    border-left-color var(--dur) var(--ease);
}

.page-about .team-stat:hover,
.page-about .team-stat:focus-visible {
  transform: translateY(-2px);
  border-color: var(--accent);
  border-left-color: var(--accent);
}

.page-about .team-stat .stat-num {
  font-family: var(--font-mono);
  font-size: 32px;
  line-height: 1;
  color: var(--c-green-deep);
}

.page-about .team-stat .stat-label {
  font-family: var(--font-display);
  font-size: 14.5px;
  letter-spacing: 0.04em;
  color: var(--c-night);
}

.page-about .team-role {
  font-size: 13px;
  line-height: 1.7;
  color: var(--text-muted);
}

/* ---------- 五道工序 ---------- */
.page-about .flow-steps {
  list-style: none;
  margin: 0 0 24px;
  padding: 0 0 0 14px;
  display: grid;
  gap: 0;
  border-left: 1px solid var(--hairline);
}

.page-about .flow-steps li {
  position: relative;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 12px;
  align-items: baseline;
  padding: 11px 0 11px 4px;
  font-size: 15px;
  line-height: 1.75;
}

.page-about .flow-steps li::before {
  content: "";
  position: absolute;
  left: -19px;
  top: 19px;
  width: 8px;
  height: 8px;
  background: var(--c-mint);
}

.page-about .flow-steps li:last-child::before {
  background: var(--accent);
}

.page-about .flow-steps .num {
  font-size: 12.5px;
  letter-spacing: 0.04em;
  color: var(--c-blue);
}

/* ---------- 覆盖数字带 ---------- */
.page-about .coverage-band {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(110px, 1fr));
  gap: 1px;
  margin: 0 0 24px;
  background: var(--hairline);
  border: 1px solid var(--hairline);
}

.page-about .cov-item {
  display: grid;
  gap: 6px;
  padding: 16px 14px;
  background: var(--surface);
}

.page-about .cov-item .stat-num {
  font-family: var(--font-mono);
  font-size: clamp(26px, 4.2vw, 38px);
  line-height: 1;
  color: var(--c-green-deep);
}

.page-about .cov-item .stat-label {
  font-size: 13px;
  letter-spacing: 0.03em;
  color: var(--text-muted);
}

.page-about .cov-item--accent {
  background: var(--c-sand);
}

.page-about .cov-item--accent .stat-num,
.page-about .cov-item--accent .stat-label {
  color: var(--c-night);
}

/* ---------- 频道清单 ---------- */
.page-about .channel-rows {
  list-style: none;
  margin: 0 0 22px;
  padding: 0;
}

.page-about .channel-row {
  display: grid;
  gap: 4px;
  padding: 14px 0;
  border-top: 1px solid var(--hairline);
}

.page-about .channel-row:last-child {
  border-bottom: 1px solid var(--hairline);
}

.page-about .channel-name {
  font-family: var(--font-display);
  font-size: 16px;
  letter-spacing: 0.05em;
  color: var(--c-green-deep);
  display: flex;
  align-items: center;
  gap: 8px;
}

.page-about .channel-name::before {
  content: "";
  width: 10px;
  height: 2px;
  background: var(--accent);
  flex: none;
}

.page-about .channel-desc {
  font-size: 15px;
  line-height: 1.78;
  color: var(--text-muted);
}

.page-about .cadence-line {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px 8px;
  font-size: 14.5px;
  line-height: 1.9;
  color: var(--text-muted);
}

/* ---------- 合作生态 ---------- */
.page-about .eco-map {
  display: grid;
  gap: 14px;
  margin: 0 0 22px;
  padding: 18px 16px;
  background: var(--surface);
  border: 1px solid var(--hairline);
  border-top: 3px solid var(--c-blue);
}

.page-about .eco-core {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--c-blue);
}

.page-about .eco-nodes {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
}

.page-about .eco-nodes li {
  display: grid;
  gap: 6px;
  padding: 12px 12px 12px 14px;
  background: var(--c-fog);
  border-left: 2px solid var(--c-mint);
  transition: border-left-color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.page-about .eco-nodes li:hover,
.page-about .eco-nodes li:focus-visible {
  border-left-color: var(--accent);
  background: #ffffff;
}

.page-about .eco-name {
  font-family: var(--font-display);
  font-size: 15px;
  letter-spacing: 0.04em;
  color: var(--c-green-deep);
}

.page-about .eco-detail {
  font-size: 13px;
  line-height: 1.72;
  color: var(--text-muted);
}

/* ---------- 结尾 CTA ---------- */
.page-about .about-close {
  margin-top: clamp(20px, 4vw, 36px);
  padding: clamp(26px, 5vw, 46px) clamp(20px, 4vw, 40px);
  background: var(--c-night);
  border-top: 0;
  color: var(--c-fog);
}

.page-about .about-close .chapter-head .section-num {
  color: var(--c-sand);
  opacity: 0.55;
}

.page-about .about-close .chapter-head h2 {
  color: var(--c-fog);
}

.page-about .about-close .chapter-body p {
  color: rgba(245, 247, 242, 0.82);
}

.page-about .close-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 22px;
}

.page-about .about-close .btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 20px;
  border: 1px solid rgba(245, 247, 242, 0.5);
  background: transparent;
  color: var(--c-fog);
  font-size: 15px;
  letter-spacing: 0.03em;
  text-decoration: none;
  transition: background-color var(--dur) var(--ease), color var(--dur) var(--ease),
    border-color var(--dur) var(--ease);
}

.page-about .about-close .btn:hover,
.page-about .about-close .btn:focus-visible {
  background: var(--c-fog);
  border-color: var(--c-fog);
  color: var(--c-night);
}

.page-about .about-close .btn-primary {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--c-night);
}

.page-about .about-close .btn-primary:hover,
.page-about .about-close .btn-primary:focus-visible {
  background: var(--c-sand);
  border-color: var(--c-sand);
  color: var(--c-night);
}

/* ---------- 中等宽度 ---------- */
@media (min-width: 620px) {
  .page-about .team-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1px;
    background: var(--hairline);
    border: 1px solid var(--hairline);
  }

  .page-about .team-stat {
    border: 0;
    border-top: 3px solid var(--c-mint);
  }

  .page-about .channel-row {
    grid-template-columns: 140px minmax(0, 1fr);
    gap: 22px;
    align-items: baseline;
  }

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

  .page-about .chapter-head {
    grid-template-columns: auto minmax(0, 1fr);
    gap: 18px;
    align-items: start;
  }

  .page-about .chapter-head .section-num {
    padding-top: 2px;
  }
}

/* ---------- 桌面分屏 ---------- */
@media (min-width: 960px) {
  .page-about .about-shell {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: clamp(40px, 5vw, 72px);
  }

  .page-about .about-rail {
    position: sticky;
    top: 96px;
    align-self: start;
  }

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

  .page-about .about-hero h1 {
    max-width: 24ch;
  }
}

@media (min-width: 1200px) {
  .page-about {
    --about-rail-w: 320px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .team-stat,
  .page-about .rail-nav a,
  .page-about .eco-nodes li,
  .page-about .about-close .btn {
    transition: none;
  }

  .page-about .team-stat:hover,
  .page-about .team-stat:focus-visible {
    transform: none;
  }
}