.page-about {
  --about-rail: 210px;
  --about-rule: rgba(11, 18, 26, 0.14);
  --about-rule-ink: rgba(246, 241, 231, 0.16);
  --about-skew: -14deg;
  background: var(--paper);
  color: var(--char);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  background: var(--ink);
  color: var(--paper);
  padding: 24px 0 0;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, var(--grid-ink) 1px, transparent 1px),
    linear-gradient(to bottom, var(--grid-ink) 1px, transparent 1px);
  background-size: 72px 72px;
  pointer-events: none;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  left: -10%;
  bottom: -160px;
  width: 120%;
  height: 240px;
  background: linear-gradient(100deg, transparent 30%, rgba(255, 106, 43, 0.16) 50%, transparent 70%);
  transform: rotate(var(--about-skew));
  pointer-events: none;
}

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

.page-about .about-hero .breadcrumbs {
  margin-bottom: 28px;
}

.page-about .about-hero-grid {
  display: grid;
  gap: 32px;
  align-items: center;
  padding-bottom: 32px;
}

.page-about .about-hero-copy .eyebrow {
  color: var(--teal);
}

.page-about .about-hero h1 {
  margin: 12px 0 20px;
  font-size: clamp(2.2rem, 8vw, 4.4rem);
  line-height: 1.06;
  letter-spacing: -0.02em;
  font-weight: 900;
  color: var(--paper);
}

.page-about .about-hero h1 br {
  display: none;
}

.page-about .lede {
  max-width: 60ch;
  color: rgba(246, 241, 231, 0.78);
  font-size: 1rem;
  line-height: 1.8;
}

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

.page-about .about-hero-visual {
  position: relative;
}

.page-about .city-map {
  display: block;
  width: 100%;
  max-width: 480px;
  height: auto;
  margin: 0 auto;
  border-radius: var(--r-lg);
  background: var(--ink-2);
  padding: 8px;
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.35);
}

.page-about .city-map-route,
.page-about .city-map-branch {
  stroke-dasharray: 900;
  stroke-dashoffset: 900;
  animation: about-draw 900ms var(--ease) 120ms forwards;
}

.page-about .city-map-branch {
  stroke-dasharray: 6 8;
  stroke-dashoffset: 0;
  opacity: 0;
  animation: about-fade 700ms var(--ease) 700ms forwards;
}

@keyframes about-draw {
  to { stroke-dashoffset: 0; }
}

@keyframes about-fade {
  to { opacity: 1; }
}

/* ---------- 章节跳转胶囊 ---------- */
.page-about .about-jump {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding: 18px 0 26px;
  border-top: 1px solid var(--line-paper);
}

.page-about .about-jump .pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  transition: transform 120ms var(--ease), background-color 120ms var(--ease), color 120ms var(--ease);
}

.page-about .about-jump .pill .mono {
  color: var(--signal);
  font-size: 0.7rem;
}

.page-about .about-jump .pill:hover,
.page-about .about-jump .pill:focus-visible {
  background: var(--signal);
  color: var(--ink);
  transform: translateY(-2px);
}

.page-about .about-jump .pill:hover .mono,
.page-about .about-jump .pill:focus-visible .mono {
  color: var(--ink);
}

/* ---------- 通栏视觉带 ---------- */
.page-about .about-band {
  margin: 0;
  line-height: 0;
  background: var(--ink-2);
}

.page-about .about-band img {
  display: block;
  width: 100%;
  height: clamp(180px, 34vw, 380px);
  object-fit: cover;
  filter: saturate(0.9) contrast(1.05);
}

/* ---------- 章节通用 ---------- */
.page-about .about-section {
  padding: 56px 0;
}

.page-about .about-section--paper {
  background: var(--paper);
}

.page-about .about-section--tint {
  background: var(--paper-2);
}

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

.page-about .chapter-grid {
  display: grid;
  gap: 20px;
}

.page-about .chapter-rail {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding-left: 18px;
  border-left: 1px solid var(--about-rule);
}

.page-about .about-section--ink .chapter-rail {
  border-left-color: var(--about-rule-ink);
}

.page-about .chapter-rail::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -22px;
  width: 64px;
  height: 1px;
  background: linear-gradient(to right, var(--signal), transparent);
  transform: rotate(var(--about-skew));
  transform-origin: left center;
}

.page-about .chapter-num {
  font-family: var(--mono);
  font-size: 2.4rem;
  line-height: 1;
  font-weight: 700;
  color: var(--signal);
  letter-spacing: -0.02em;
}

.page-about .chapter-rail .coord {
  color: var(--muted);
}

.page-about .rail-note {
  font-size: 0.8125rem;
  line-height: 1.7;
  color: var(--muted);
  max-width: 22ch;
}

.page-about .chapter-body h2 {
  margin: 0 0 18px;
  font-size: clamp(1.5rem, 4.4vw, 2.1rem);
  line-height: 1.25;
  letter-spacing: -0.01em;
  font-weight: 800;
  color: var(--char);
}

.page-about .chapter-body p {
  margin: 0 0 16px;
  font-size: 1rem;
  line-height: 1.8;
  color: #22303c;
}

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

.page-about .chapter-body .mono {
  background: rgba(255, 106, 43, 0.12);
  color: #b23c0c;
  padding: 1px 6px;
  border-radius: 6px;
  font-size: 0.9em;
}

/* ---------- 引用块 ---------- */
.page-about .about-quote {
  margin: 26px 0;
  padding: 20px 22px;
  background: var(--paper);
  border-left: 4px solid var(--signal);
  border-radius: 0 var(--r) var(--r) 0;
}

.page-about .about-section--tint .about-quote {
  background: #fdfaf4;
}

.page-about .about-quote p {
  margin: 0;
  font-size: 1.0625rem;
  line-height: 1.75;
  font-weight: 600;
  color: var(--char);
}

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

.page-about .about-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  border-radius: var(--r);
  background: var(--ink-2);
}

.page-about .about-figure .media-cap {
  margin-top: 10px;
  font-size: 0.8125rem;
  line-height: 1.7;
  color: var(--muted);
}

/* ---------- 收录标准列表 ---------- */
.page-about .criteria-list {
  list-style: none;
  margin: 22px 0 26px;
  padding: 0;
  display: grid;
  gap: 2px;
}

.page-about .criteria-list li {
  display: grid;
  grid-template-columns: 44px 1fr;
  gap: 12px;
  align-items: start;
  padding: 16px 14px;
  background: rgba(253, 250, 244, 0.75);
  border-radius: var(--r-sm);
  transition: background-color 120ms var(--ease), transform 120ms var(--ease);
}

.page-about .criteria-list li:hover {
  background: #fdfaf4;
  transform: translateX(3px);
}

.page-about .criteria-no {
  color: var(--signal);
  font-size: 0.8125rem;
  letter-spacing: 0.08em;
  padding-top: 3px;
}

.page-about .criteria-text {
  font-size: 0.9688rem;
  line-height: 1.75;
  color: #22303c;
}

.page-about .criteria-text strong {
  color: var(--char);
  font-weight: 700;
}

/* ---------- 供稿流程 ---------- */
.page-about .flow-list {
  list-style: none;
  margin: 22px 0 24px;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .flow-list li {
  display: grid;
  gap: 6px;
  padding: 16px 18px;
  background: var(--paper);
  border-radius: var(--r);
  border-top: 2px solid var(--teal);
}

.page-about .flow-step {
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  color: #0f8f6b;
}

.page-about .flow-list p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: #22303c;
}

/* ---------- 深色时间线 ---------- */
.page-about .about-ink-head {
  max-width: 62ch;
  margin-bottom: 36px;
}

.page-about .about-ink-head .eyebrow {
  color: var(--teal);
}

.page-about .about-ink-head h2 {
  margin: 12px 0 14px;
  font-size: clamp(1.6rem, 5vw, 2.4rem);
  line-height: 1.25;
  font-weight: 800;
  color: var(--paper);
}

.page-about .about-ink-head .lede {
  color: rgba(246, 241, 231, 0.7);
}

.page-about .timeline {
  list-style: none;
  margin: 0;
  padding: 0 0 0 4px;
  display: grid;
  gap: 4px;
}

.page-about .timeline li {
  position: relative;
}

.page-about .timeline li::before {
  content: "";
  position: absolute;
  left: 9px;
  top: 26px;
  bottom: -4px;
  width: 2px;
  background: linear-gradient(to bottom, rgba(23, 227, 168, 0.45), rgba(23, 227, 168, 0.08));
}

.page-about .timeline li:last-child::before {
  display: none;
}

.page-about .timeline-node {
  position: relative;
  display: grid;
  gap: 6px;
  padding: 14px 16px 20px 40px;
  border-radius: var(--r);
  color: inherit;
  text-decoration: none;
  transition: background-color 120ms var(--ease), transform 120ms var(--ease);
}

.page-about .timeline-node:hover,
.page-about .timeline-node:focus-visible {
  background: var(--ink-2);
  transform: translateY(-2px);
}

.page-about .timeline-dot {
  position: absolute;
  left: 1px;
  top: 16px;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--ink);
  border: 2px solid var(--teal);
  transition: border-color 120ms var(--ease), box-shadow 120ms var(--ease), background-color 120ms var(--ease);
}

.page-about .timeline-node:hover .timeline-dot,
.page-about .timeline-node:focus-visible .timeline-dot {
  border-color: var(--signal);
  background: var(--signal);
  box-shadow: 0 0 0 5px rgba(255, 106, 43, 0.18);
}

.page-about .timeline-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
}

.page-about .timeline-meta .mono {
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  color: var(--teal);
  padding: 2px 8px;
  border: 1px solid var(--line-teal);
  border-radius: var(--pill);
}

.page-about .timeline-meta .coord {
  color: rgba(246, 241, 231, 0.5);
}

.page-about .timeline-title {
  font-size: 1.0625rem;
  font-weight: 700;
  color: var(--paper);
  line-height: 1.4;
}

.page-about .timeline-text {
  font-size: 0.9375rem;
  line-height: 1.75;
  color: rgba(246, 241, 231, 0.66);
  max-width: 56ch;
}

/* ---------- 收尾 ---------- */
.page-about .about-next {
  max-width: 62ch;
}

.page-about .about-next h2 {
  margin: 0 0 14px;
  font-size: clamp(1.4rem, 4vw, 1.9rem);
  font-weight: 800;
  color: var(--char);
}

.page-about .about-next p {
  margin: 0 0 20px;
  font-size: 1rem;
  line-height: 1.8;
  color: #22303c;
}

.page-about .about-next-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 26px;
}

/* ---------- 焦点可见 ---------- */
.page-about a:focus-visible {
  outline: 2px solid var(--teal);
  outline-offset: 2px;
  border-radius: 4px;
}

/* ---------- 平板及以上 ---------- */
@media (min-width: 760px) {
  .page-about .about-hero {
    padding-top: 36px;
  }

  .page-about .about-hero h1 br {
    display: inline;
  }

  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    gap: 40px;
    padding-bottom: 40px;
  }

  .page-about .about-section {
    padding: 76px 0;
  }

  .page-about .criteria-list {
    grid-template-columns: 1fr 1fr;
  }

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

  .page-about .timeline {
    grid-template-columns: 1fr 1fr;
    gap: 6px 28px;
  }

  .page-about .timeline li::before {
    display: none;
  }

  .page-about .timeline-node {
    border-top: 1px solid var(--line-paper);
    padding-top: 22px;
  }
}

/* ---------- 桌面：左右分置长文版式 ---------- */
@media (min-width: 1024px) {
  .page-about .chapter-grid {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: 64px;
  }

  .page-about .chapter-rail {
    position: sticky;
    top: calc(var(--header-h-compact) + 28px);
    align-self: start;
  }

  .page-about .chapter-body {
    max-width: 68ch;
  }

  .page-about .about-hero h1 {
    font-size: clamp(2.8rem, 5.4vw, 4.6rem);
  }

  .page-about .timeline {
    grid-template-columns: repeat(3, 1fr);
    gap: 8px 24px;
  }

  .page-about .about-band img {
    height: clamp(260px, 26vw, 400px);
  }
}

/* ---------- 降级动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .city-map-route,
  .page-about .city-map-branch {
    animation: none;
    stroke-dashoffset: 0;
    opacity: 1;
  }

  .page-about .about-jump .pill,
  .page-about .criteria-list li,
  .page-about .timeline-node,
  .page-about .timeline-dot {
    transition: none;
  }

  .page-about .about-jump .pill:hover,
  .page-about .criteria-list li:hover,
  .page-about .timeline-node:hover,
  .page-about .timeline-node:focus-visible {
    transform: none;
  }
}