.page-about {
  --about-rail: 104px;
  --about-tint: rgba(18, 59, 46, 0.35);
  --about-glow: rgba(31, 245, 208, 0.42);
}

.page-about .breadcrumb {
  margin: clamp(18px, 3vw, 28px) 0 0;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: clamp(22px, 3.6vw, 44px) 0 clamp(32px, 5vw, 64px);
  border-bottom: 1px solid var(--line-soft);
  background:
    radial-gradient(120% 100% at 88% -10%, rgba(18, 59, 46, 0.6), transparent 62%),
    linear-gradient(180deg, rgba(11, 27, 42, 0.72), rgba(5, 13, 11, 0) 78%);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: auto 0 0 0;
  height: 3px;
  background: linear-gradient(90deg, var(--cyan), rgba(242, 184, 75, 0.55), transparent 70%);
  opacity: 0.5;
}

.page-about .about-hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(22px, 4vw, 44px);
}

.page-about .about-hero-lead .h1 {
  margin: 10px 0 18px;
  max-width: 18em;
}

.page-about .about-hero-lead .lede {
  max-width: 46em;
}

.page-about .about-hero-actions {
  margin-top: clamp(20px, 3vw, 30px);
  gap: 12px;
  flex-wrap: wrap;
}

.page-about .about-hero-side {
  align-self: start;
  padding: 20px 20px 18px;
  border: 1px solid var(--line-cyan);
  border-radius: var(--r-md);
  background: var(--glass-green);
  backdrop-filter: blur(8px);
  box-shadow: var(--shadow-soft);
}

.page-about .about-side-title {
  margin: 0 0 12px;
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .about-toc {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 2px;
}

.page-about .about-toc-link {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 9px 10px;
  border-radius: var(--r-xs);
  color: var(--paper);
  text-decoration: none;
  font-size: 16px;
  border-left: 2px solid transparent;
  transition: background 180ms var(--ease), border-color 180ms var(--ease), color 180ms var(--ease);
}

.page-about .about-toc-link .num {
  color: var(--amber);
  font-size: 13px;
  letter-spacing: 0.08em;
}

.page-about .about-toc-link:hover,
.page-about .about-toc-link:focus-visible {
  background: rgba(31, 245, 208, 0.08);
  border-left-color: var(--cyan);
  color: var(--cyan);
}

.page-about .about-side-note {
  margin-top: 16px;
  padding-top: 14px;
  border-top: 1px solid var(--line-soft);
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
}

.page-about .about-side-key {
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .about-side-val {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--amber);
}

/* ---------- 章节容器 ---------- */
.page-about .chapter {
  padding: clamp(32px, 5.5vw, 68px) 0;
  border-bottom: 1px solid var(--line-soft);
}

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

.page-about .chapter-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(14px, 2.4vw, 28px);
}

.page-about .chapter-rail {
  display: flex;
  align-items: baseline;
  gap: 14px;
}

.page-about .chapter-num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(2.4rem, 7vw, 3.4rem);
  line-height: 1;
  letter-spacing: -0.04em;
  color: rgba(31, 245, 208, 0.16);
  -webkit-text-stroke: 1px rgba(31, 245, 208, 0.5);
}

.page-about .chapter-kicker {
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .chapter-body .h2 {
  margin: 0 0 14px;
}

.page-about .chapter-body p {
  margin: 0 0 14px;
  color: var(--paper);
}

.page-about .chapter-lede {
  color: var(--muted) !important;
  max-width: 40em;
}

/* ---------- 01 归档方法 ---------- */
.page-about .mission-split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(18px, 3vw, 32px);
  margin-top: clamp(18px, 3vw, 26px);
}

.page-about .mission-list {
  list-style: none;
  margin: 18px 0 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .mission-list li {
  position: relative;
  padding-left: 22px;
  color: var(--muted);
  font-size: 16px;
  line-height: 1.75;
}

.page-about .mission-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 12px;
  height: 2px;
  background: var(--cyan);
}

.page-about .figure-frame {
  margin: 0;
  overflow: hidden;
  border-radius: var(--r-md);
  border: 1px solid var(--line-soft);
}

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

.page-about .figure-caption {
  margin: 0;
  padding: 12px 14px;
  font-size: 14px;
  line-height: 1.6;
  color: var(--muted);
  background: rgba(11, 27, 42, 0.72);
  border-top: 1px solid var(--line-soft);
}

.page-about .mission-figure {
  align-self: start;
}

/* ---------- 02 小组分工 ---------- */
.page-about .squad-grid {
  list-style: none;
  margin: clamp(18px, 3vw, 28px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
}

.page-about .squad-card {
  padding: 22px 20px;
  border: 1px solid var(--line-soft);
  border-radius: var(--r-md);
  background: var(--about-tint);
  backdrop-filter: blur(6px);
  transition: border-color 200ms var(--ease), background 200ms var(--ease), transform 200ms var(--ease);
}

.page-about .squad-card .h3 {
  margin: 0 0 10px;
  color: var(--paper);
}

.page-about .squad-card p {
  margin: 0 0 12px;
  font-size: 16px;
  line-height: 1.78;
  color: var(--muted);
}

.page-about .squad-card--a {
  background: rgba(18, 59, 46, 0.22);
  border-top: 2px solid rgba(31, 245, 208, 0.6);
}

.page-about .squad-card--b {
  background: rgba(18, 59, 46, 0.34);
  border-top: 2px solid rgba(242, 184, 75, 0.6);
}

.page-about .squad-card--c {
  background: rgba(18, 59, 46, 0.46);
  border-top: 2px solid rgba(232, 255, 249, 0.32);
}

.page-about .squad-card--d {
  background: rgba(11, 27, 42, 0.62);
  border-top: 2px solid rgba(168, 192, 186, 0.42);
}

.page-about .squad-card:hover,
.page-about .squad-card:focus-within {
  border-color: var(--line-cyan);
  border-top-color: var(--cyan);
}

.page-about .squad-meta {
  margin: 0 !important;
  padding-top: 12px;
  border-top: 1px solid var(--line-soft);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--cyan) !important;
  opacity: 0.85;
}

/* ---------- 03 整理流程 ---------- */
.page-about .flow-steps {
  list-style: none;
  margin: clamp(18px, 3vw, 26px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 12px;
}

.page-about .flow-step {
  padding: 18px 16px;
  border: 1px solid var(--line-soft);
  border-radius: var(--r-sm);
  background: linear-gradient(180deg, rgba(11, 27, 42, 0.92), rgba(10, 31, 25, 0.7));
  transition: border-color 200ms var(--ease), background 200ms var(--ease);
}

.page-about .flow-step:hover {
  border-color: var(--line-cyan);
  background: linear-gradient(180deg, rgba(18, 59, 46, 0.85), rgba(10, 31, 25, 0.8));
}

.page-about .flow-step-num {
  display: block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.18em;
  color: var(--amber);
}

.page-about .flow-step .h3 {
  margin: 0 0 8px;
  font-size: 1.1rem;
}

.page-about .flow-step p {
  margin: 0;
  font-size: 15px;
  line-height: 1.72;
  color: var(--muted);
}

.page-about .flow-figure {
  margin-top: clamp(20px, 3vw, 30px);
}

/* ---------- 04 发展节点 ---------- */
.page-about .timeline-wrap {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 3.4vw, 40px);
  margin-top: clamp(18px, 3vw, 28px);
}

.page-about .timeline-figure {
  align-self: start;
}

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

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 8px;
  bottom: 14px;
  width: 2px;
  background: linear-gradient(180deg, var(--cyan), rgba(242, 184, 75, 0.6) 55%, rgba(232, 255, 249, 0.08));
}

.page-about .tl-item {
  position: relative;
  padding: 0 0 22px 32px;
}

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

.page-about .tl-item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 6px;
  width: 14px;
  height: 14px;
  border-radius: 3px;
  background: var(--ink-900);
  border: 2px solid var(--cyan);
  transition: background 180ms var(--ease), border-color 180ms var(--ease), box-shadow 180ms var(--ease);
}

.page-about .tl-item:hover::before,
.page-about .tl-item:focus-within::before {
  background: var(--amber);
  border-color: var(--amber);
  box-shadow: 0 0 0 4px rgba(242, 184, 75, 0.16);
}

.page-about .tl-year {
  display: block;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--amber);
  margin-bottom: 6px;
}

.page-about .tl-body .h3 {
  margin: 0 0 6px;
  font-size: 1.12rem;
  transition: color 180ms var(--ease);
}

.page-about .tl-item:hover .tl-body .h3 {
  color: var(--cyan);
}

.page-about .tl-body p {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.75;
  color: var(--muted);
}

/* ---------- 05 资料卡与服务 ---------- */
.page-about .quality-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin-top: clamp(18px, 3vw, 26px);
}

.page-about .quality-card {
  padding: 22px 20px;
  border-radius: var(--r-md);
  background: linear-gradient(160deg, rgba(18, 59, 46, 0.72), rgba(11, 27, 42, 0.86));
}

.page-about .quality-card .h3 {
  margin: 0 0 10px;
  color: var(--paper);
}

.page-about .quality-card p {
  margin: 0;
  font-size: 16px;
  line-height: 1.76;
  color: var(--muted);
}

/* ---------- 06 档案标签 ---------- */
.page-about .tag-wall {
  list-style: none;
  margin: clamp(18px, 3vw, 26px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(148px, 1fr));
  gap: 10px;
}

.page-about .tag-cell {
  display: grid;
  gap: 6px;
  padding: 16px 16px 18px;
  border: 1px solid var(--line-soft);
  border-radius: var(--r-sm);
  background: rgba(11, 27, 42, 0.58);
  transition: border-color 180ms var(--ease), background 180ms var(--ease);
}

.page-about .tag-cell:hover {
  border-color: var(--line-cyan);
  background: rgba(18, 59, 46, 0.5);
}

.page-about .tag-k {
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .tag-v {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 1.42rem;
  line-height: 1.2;
  color: var(--paper);
}

/* ---------- 结尾入口 ---------- */
.page-about .about-cta {
  padding: clamp(34px, 6vw, 70px) 0 clamp(44px, 7vw, 88px);
  background:
    radial-gradient(90% 120% at 10% 0%, rgba(18, 59, 46, 0.55), transparent 64%),
    linear-gradient(180deg, rgba(11, 27, 42, 0.7), rgba(5, 13, 11, 0.9));
}

.page-about .about-cta .h2 {
  margin: 0 0 clamp(18px, 3vw, 28px);
}

.page-about .cta-links {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
}

.page-about .cta-link {
  display: grid;
  gap: 6px;
  padding: 18px 20px;
  border: 1px solid var(--line-soft);
  border-left: 2px solid var(--line-cyan);
  border-radius: var(--r-sm);
  background: rgba(10, 31, 25, 0.62);
  text-decoration: none;
  transition: border-color 180ms var(--ease), background 180ms var(--ease), transform 180ms var(--ease);
}

.page-about .cta-link:hover,
.page-about .cta-link:focus-visible {
  border-color: var(--line-cyan);
  border-left-color: var(--cyan);
  background: rgba(18, 59, 46, 0.6);
  transform: translateY(-2px);
}

.page-about .cta-link-title {
  font-family: var(--font-head);
  font-weight: 800;
  font-size: 1.08rem;
  color: var(--paper);
  letter-spacing: -0.01em;
}

.page-about .cta-link-desc {
  font-size: 15px;
  line-height: 1.66;
  color: var(--muted);
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .squad-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

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

@media (min-width: 860px) {
  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 1.5fr) minmax(250px, 0.78fr);
    align-items: start;
  }

  .page-about .chapter-grid {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: clamp(20px, 3vw, 36px);
  }

  .page-about .chapter-rail {
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
    position: sticky;
    top: 24px;
  }

  .page-about .chapter-num {
    font-size: 4.2rem;
  }

  .page-about .mission-split {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 0.92fr);
    align-items: start;
  }

  .page-about .timeline-wrap {
    grid-template-columns: minmax(0, 0.82fr) minmax(0, 1.18fr);
    align-items: start;
  }

  .page-about .timeline-figure {
    position: sticky;
    top: 24px;
  }
}

@media (min-width: 1100px) {
  .page-about .quality-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about .squad-card,
  .page-about .flow-step,
  .page-about .tag-cell,
  .page-about .cta-link,
  .page-about .tl-item::before {
    transition: none;
  }

  .page-about .cta-link:hover,
  .page-about .cta-link:focus-visible {
    transform: none;
  }
}