.page-about {
  --about-cut: 12px;
  --teal: #5FD3B2;
  display: block;
  background: var(--pitch-deep);
  color: var(--ink);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding: clamp(18px, 4vw, 38px) 0 clamp(28px, 5vw, 56px);
  border-bottom: 1px solid var(--line);
}

.page-about .about-hero__eyebrow {
  margin: clamp(20px, 3vw, 34px) 0 12px;
}

.page-about .about-hero__title {
  margin: 0 0 clamp(16px, 2.4vw, 24px);
  font-family: var(--font-display);
  font-size: clamp(36px, 7.6vw, 88px);
  font-weight: 800;
  line-height: 0.98;
  letter-spacing: -0.01em;
  color: var(--ink);
  max-width: 18ch;
}

.page-about .about-hero__lead {
  margin: 0;
  max-width: 64ch;
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.75;
  color: var(--ink-soft);
}

.page-about .about-hero__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(26px, 4vw, 44px) 0 0;
  background: var(--line-strong);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 16px), calc(100% - 16px) 100%, 0 100%);
}

.page-about .about-stat {
  display: flex;
  flex-direction: column;
  gap: 3px;
  padding: clamp(14px, 2.2vw, 22px) clamp(14px, 2vw, 20px);
  background: var(--pitch-mid);
}

.page-about .about-stat__value {
  font-family: var(--font-display);
  font-size: clamp(34px, 5vw, 52px);
  font-weight: 800;
  line-height: 1;
  color: var(--volt);
}

.page-about .about-stat__unit {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--electric);
}

.page-about .about-stat__label {
  margin-top: 6px;
  font-size: 13px;
  line-height: 1.5;
  color: var(--muted);
}

/* ---------- 通用标题 ---------- */
.page-about .about-h2 {
  margin: 8px 0 14px;
  font-family: var(--font-display);
  font-size: clamp(26px, 4.2vw, 44px);
  font-weight: 700;
  line-height: 1.12;
  letter-spacing: -0.01em;
  color: var(--ink);
}

/* ---------- 图片容器 ---------- */
.page-about .about-figure {
  margin: 0 0 clamp(20px, 3.4vw, 32px);
  background: var(--pitch-mid);
  overflow: hidden;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 18px), calc(100% - 18px) 100%, 0 100%);
  border-left: 3px solid var(--volt);
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  filter: saturate(0.9);
}

.page-about .about-figure--wide img { aspect-ratio: 1400 / 800; }
.page-about .about-figure--band img { aspect-ratio: 1600 / 600; }
.page-about .about-figure--square {
  margin-bottom: 0;
  border-left-color: var(--electric);
}
.page-about .about-figure--square img { aspect-ratio: 900 / 700; }

.page-about .about-cities__wrap .about-figure--band {
  margin-top: clamp(14px, 2vw, 22px);
  border-left-color: var(--pulse);
}

/* ---------- 时间轴 ---------- */
.page-about .about-history__lead {
  margin-bottom: clamp(20px, 3vw, 30px);
}

.page-about .about-timeline {
  position: relative;
  margin: 0;
  padding: 6px 0 6px 30px;
  list-style: none;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 14px;
  bottom: 14px;
  width: 2px;
  background: linear-gradient(180deg, var(--volt) 0%, var(--electric) 45%, var(--pulse) 82%, transparent 100%);
}

.page-about .about-timeline__item {
  position: relative;
}

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  left: -28px;
  top: 22px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--pitch-deep);
  border: 2px solid var(--volt);
  box-sizing: border-box;
}

.page-about .about-timeline__node {
  margin-bottom: 10px;
  padding: 14px 16px 14px 18px;
  background: var(--pitch-mid);
  border-left: 2px solid var(--line);
  transition: border-color 0.22s ease, background-color 0.22s ease;
}

.page-about .about-timeline__node:hover {
  border-left-color: var(--line-strong);
}

.page-about .about-timeline__node[open] {
  border-left-color: var(--volt);
  background: color-mix(in srgb, var(--pitch-mid) 82%, var(--volt) 18%);
}

.page-about .about-timeline__summary {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 6px 16px;
  cursor: pointer;
  list-style: none;
}

.page-about .about-timeline__summary::-webkit-details-marker { display: none; }

.page-about .about-timeline__summary::after {
  content: "+";
  font-family: var(--font-mono);
  font-size: 20px;
  line-height: 1;
  color: var(--volt);
  padding-left: 8px;
}

.page-about .about-timeline__node[open] .about-timeline__summary::after {
  content: "\2212";
}

.page-about .about-timeline__meta {
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 74px;
}

.page-about .about-timeline__season {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--electric);
}

.page-about .about-timeline__year {
  font-family: var(--font-display);
  font-size: clamp(20px, 3.2vw, 30px);
  font-weight: 800;
  line-height: 1.05;
  color: var(--ink);
}

.page-about .about-timeline__head {
  font-size: clamp(15px, 1.7vw, 18px);
  font-weight: 600;
  line-height: 1.4;
  color: var(--ink);
}

.page-about .about-timeline__body {
  margin: 12px 0 4px;
  padding-top: 12px;
  border-top: 1px dashed var(--line);
  font-size: 14px;
  line-height: 1.75;
  color: var(--ink-soft);
  max-width: 62ch;
}

/* ---------- 四城卡片 ---------- */
.page-about .about-cities__lead {
  margin-bottom: clamp(16px, 2.4vw, 24px);
}

.page-about .about-cities {
  display: grid;
  grid-auto-flow: column;
  grid-auto-columns: minmax(250px, 78%);
  gap: 12px;
  overflow-x: auto;
  overscroll-behavior-x: contain;
  scroll-snap-type: x mandatory;
  padding-bottom: 18px;
  scrollbar-width: thin;
  scrollbar-color: var(--graphite) transparent;
}

.page-about .about-cities::-webkit-scrollbar { height: 6px; }
.page-about .about-cities::-webkit-scrollbar-track { background: var(--pitch-mid); }
.page-about .about-cities::-webkit-scrollbar-thumb { background: var(--graphite); }

.page-about .about-city {
  scroll-snap-align: start;
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 20px 18px 24px;
  background: var(--pitch-deep);
  border-top: 3px solid var(--card-accent, var(--volt));
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--about-cut)), calc(100% - var(--about-cut)) 100%, 0 100%);
}

.page-about .about-city--sh { --card-accent: var(--volt); }
.page-about .about-city--bj { --card-accent: var(--electric); }
.page-about .about-city--gz { --card-accent: var(--pulse); }
.page-about .about-city--cd { --card-accent: var(--teal); }

.page-about .about-city__tag {
  align-self: flex-start;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  padding: 4px 10px;
  border: 1px solid var(--card-accent);
  color: var(--card-accent);
  border-radius: var(--pill);
}

.page-about .about-city__name {
  margin: 4px 0 0;
  font-family: var(--font-display);
  font-size: clamp(28px, 4vw, 38px);
  font-weight: 800;
  line-height: 1;
  letter-spacing: 0.01em;
  color: var(--card-accent);
}

.page-about .about-city__sub {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.5;
  color: var(--muted);
}

.page-about .about-city__text {
  margin: 6px 0 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--ink-soft);
}

/* ---------- 编辑部流程 ---------- */
.page-about .about-desk__lead {
  margin-bottom: clamp(18px, 2.6vw, 26px);
}

.page-about .about-flow__input {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  border: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}

.page-about .about-flow__tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--line);
}

.page-about .about-flow__tab {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 9px 16px;
  border: 1px solid var(--line);
  border-radius: var(--pill);
  cursor: pointer;
  font-size: 14px;
  line-height: 1.2;
  color: var(--ink-soft);
  transition: background-color 0.2s ease, border-color 0.2s ease, color 0.2s ease;
}

.page-about .about-flow__tab:hover {
  border-color: var(--line-strong);
  color: var(--ink);
}

.page-about .about-flow__num {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--muted);
}

.page-about .about-flow__tab:hover .about-flow__num { color: inherit; }

.page-about #about-flow-1:checked ~ .about-flow__tabs .about-flow__tab:nth-child(1) {
  background: var(--volt);
  border-color: var(--volt);
  color: var(--pitch-deep);
}
.page-about #about-flow-2:checked ~ .about-flow__tabs .about-flow__tab:nth-child(2) {
  background: var(--electric);
  border-color: var(--electric);
  color: var(--pitch-deep);
}
.page-about #about-flow-3:checked ~ .about-flow__tabs .about-flow__tab:nth-child(3) {
  background: var(--pulse);
  border-color: var(--pulse);
  color: var(--deep);
}

.page-about #about-flow-1:checked ~ .about-flow__tabs .about-flow__tab:nth-child(1) .about-flow__num,
.page-about #about-flow-2:checked ~ .about-flow__tabs .about-flow__tab:nth-child(2) .about-flow__num,
.page-about #about-flow-3:checked ~ .about-flow__tabs .about-flow__tab:nth-child(3) .about-flow__num {
  color: inherit;
  opacity: 0.72;
}

.page-about #about-flow-1:focus-visible ~ .about-flow__tabs .about-flow__tab:nth-child(1),
.page-about #about-flow-2:focus-visible ~ .about-flow__tabs .about-flow__tab:nth-child(2),
.page-about #about-flow-3:focus-visible ~ .about-flow__tabs .about-flow__tab:nth-child(3) {
  outline: 2px solid var(--electric);
  outline-offset: 3px;
}

.page-about .about-flow__panels {
  margin-top: clamp(18px, 2.6vw, 26px);
}

.page-about .about-flow__panel {
  display: none;
  gap: 10px;
  padding-left: 20px;
  border-left: 2px solid var(--line);
}

.page-about #about-flow-1:checked ~ .about-flow__panels .about-flow__panel:nth-child(1),
.page-about #about-flow-2:checked ~ .about-flow__panels .about-flow__panel:nth-child(2),
.page-about #about-flow-3:checked ~ .about-flow__panels .about-flow__panel:nth-child(3) {
  display: grid;
}

.page-about #about-flow-1:checked ~ .about-flow__panels .about-flow__panel:nth-child(1) { border-left-color: var(--volt); }
.page-about #about-flow-2:checked ~ .about-flow__panels .about-flow__panel:nth-child(2) { border-left-color: var(--electric); }
.page-about #about-flow-3:checked ~ .about-flow__panels .about-flow__panel:nth-child(3) { border-left-color: var(--pulse); }

.page-about .about-flow__title {
  margin: 0;
  font-size: clamp(18px, 2.2vw, 24px);
  font-weight: 700;
  line-height: 1.35;
  color: var(--ink);
}

.page-about .about-flow__text {
  margin: 0;
  max-width: 64ch;
  font-size: 15px;
  line-height: 1.75;
  color: var(--ink-soft);
}

.page-about .about-flow__out {
  margin: 2px 0 0;
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
}

.page-about .about-flow__out .bw-mono {
  display: inline-block;
  margin-right: 8px;
  padding: 2px 8px;
  border: 1px solid var(--line-strong);
  border-radius: var(--pill);
  color: var(--electric);
  font-size: 11px;
}

/* ---------- 年鉴 ---------- */
.page-about .about-almanac__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 3.4vw, 36px);
  align-items: start;
}

.page-about .about-almanac__text p {
  margin: 0 0 14px;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.75;
  color: var(--ink-soft);
}

.page-about .about-almanac__list {
  margin: 18px 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 1px;
  background: var(--line);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.page-about .about-almanac__list li {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px;
  padding: 11px 4px;
  background: var(--pitch-mid);
  font-size: 13px;
  line-height: 1.6;
  color: var(--ink-soft);
}

.page-about .about-almanac__list .bw-mono {
  min-width: 62px;
  color: var(--volt);
  font-size: 11px;
  letter-spacing: 0.06em;
}

/* ---------- 纠错 ---------- */
.page-about .about-fix__panel {
  padding: clamp(20px, 3vw, 32px) clamp(18px, 3vw, 36px);
  background: color-mix(in srgb, var(--pitch-mid) 86%, var(--pulse) 14%);
  border-left: 3px solid var(--pulse);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 18px), calc(100% - 18px) 100%, 0 100%);
}

.page-about .about-fix__text {
  margin: 0 0 20px;
  max-width: 66ch;
  font-size: 15px;
  line-height: 1.75;
  color: var(--ink-soft);
}

.page-about .about-fix__contact {
  color: var(--electric);
  word-break: break-all;
}

.page-about .about-fix__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

/* ---------- 收尾 ---------- */
.page-about .about-next {
  border-top: 1px solid var(--line);
}

.page-about .about-next__title {
  max-width: 20ch;
}

.page-about .about-next__lead {
  max-width: 62ch;
  margin: 0 0 clamp(20px, 3vw, 28px);
}

.page-about .about-next__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .about-hero__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-almanac__list li {
    padding: 12px 8px;
  }
}

@media (min-width: 900px) {
  .page-about .about-timeline {
    padding-left: 44px;
  }

  .page-about .about-timeline::before { left: 9px; }
  .page-about .about-timeline__item::before { left: -40px; }

  .page-about .about-timeline__node {
    padding: 18px 22px 18px 24px;
  }

  .page-about .about-cities {
    grid-auto-flow: row;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    overflow: visible;
    scroll-snap-type: none;
    padding-bottom: 0;
  }

  .page-about .about-city {
    padding: 22px 20px 26px;
  }

  .page-about .about-almanac__grid {
    grid-template-columns: minmax(0, 0.85fr) minmax(0, 1fr);
    align-items: center;
  }

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

@media (min-width: 1100px) {
  .page-about .about-almanac__grid {
    grid-template-columns: minmax(0, 0.8fr) minmax(0, 1.2fr);
    gap: 48px;
  }

  .page-about .about-hero__lead {
    font-size: 17px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-timeline__node,
  .page-about .about-flow__tab {
    transition: none;
  }
}