.page-about {
  --about-aside-w: 250px;
  --about-rule: 2px;
  --about-gutter: clamp(16px, 2.4vw, 28px);
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumbs ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0;
  padding: 20px 0 0;
  list-style: none;
  font-size: 13px;
  color: var(--note);
  font-family: var(--font-num);
  letter-spacing: .04em;
}

.page-about .breadcrumbs a {
  color: var(--note);
  text-decoration: none;
  border-bottom: 1px solid transparent;
}

.page-about .breadcrumbs a:hover,
.page-about .breadcrumbs a:focus-visible {
  color: var(--turf);
  border-bottom-color: currentColor;
}

.page-about .breadcrumbs li[aria-current="page"] {
  color: var(--paper);
}

.page-about .breadcrumbs li + li::before {
  content: "/";
  margin-right: 8px;
  color: var(--line);
}

/* ---------- 开篇 ---------- */
.page-about .about-open {
  padding-top: clamp(20px, 4vw, 48px);
}

.page-about .about-open__grid {
  display: grid;
  gap: clamp(28px, 5vw, 48px);
}

.page-about .about-open__text {
  border-left: var(--about-rule) solid var(--turf);
  padding-left: var(--about-gutter);
}

.page-about .about-open__text h1 {
  margin: 10px 0 20px;
  font-family: var(--font-head);
  font-size: clamp(34px, 6.6vw, 70px);
  font-weight: 900;
  line-height: .98;
  letter-spacing: -.02em;
  color: var(--paper);
}

.page-about .about-open__text .lede {
  margin: 0 0 1.1em;
  font-size: clamp(16px, 2.1vw, 20px);
  line-height: 1.6;
  color: var(--warm);
}

.page-about .about-open__text p {
  margin: 0 0 1.05em;
  color: var(--body-text);
  line-height: 1.78;
}

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

.page-about .about-open__text .note {
  max-width: 46ch;
}

.page-about .about-open__figure {
  margin: 0;
}

/* ---------- 图文框 ---------- */
.page-about .figure {
  margin: 0;
}

.page-about .figure__frame {
  border: 1px solid var(--line);
  background: var(--rock);
  box-shadow: var(--shadow-hard);
  overflow: hidden;
}

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

.page-about .figure__cap {
  margin-top: 12px;
  font-size: 12px;
  line-height: 1.6;
  color: var(--note);
  padding-left: 10px;
  border-left: 2px solid var(--line);
}

/* ---------- 通用两栏（正文 + 粘性注释栏） ---------- */
.page-about .about-grid {
  display: grid;
  gap: clamp(24px, 4vw, 40px);
}

.page-about .about-grid__main {
  border-left: var(--about-rule) solid var(--turf);
  padding-left: var(--about-gutter);
  min-width: 0;
}

.page-about .section-title {
  margin: 8px 0 22px;
  font-family: var(--font-head);
  font-size: clamp(26px, 4.4vw, 46px);
  font-weight: 800;
  line-height: 1.04;
  letter-spacing: -.02em;
  color: var(--paper);
}

.page-about .prose p {
  margin: 0 0 1.05em;
  color: var(--body-text);
  line-height: 1.8;
}

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

.page-about .eyebrow {
  margin: 0 0 4px;
}

.page-about .about-aside {
  border-top: 2px solid var(--amber);
  padding-top: 14px;
  font-size: 13px;
  line-height: 1.68;
  color: var(--note);
}

.page-about .about-aside p {
  margin: 0 0 14px;
}

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

.page-about .about-aside__label {
  font-family: var(--font-head);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--amber);
  margin-bottom: 4px !important;
}

/* ---------- 数据方法 ---------- */
.page-about .about-method__figure {
  margin-top: clamp(26px, 4vw, 40px);
}

/* ---------- 三个板块 ---------- */
.page-about .about-blocks__list {
  display: grid;
  gap: 18px;
}

.page-about .about-block {
  position: relative;
  background: var(--rock);
  border: 1px solid var(--line);
  border-left: 4px solid var(--turf);
  padding: clamp(20px, 3vw, 30px);
  box-shadow: var(--shadow-soft);
  min-width: 0;
}

.page-about .about-block:nth-child(2) {
  border-left-color: var(--amber);
}

.page-about .about-block:nth-child(3) {
  border-left-color: var(--violet);
}

.page-about .about-block__idx {
  margin: 0 0 10px;
  font-family: var(--font-num);
  font-size: 12px;
  letter-spacing: .24em;
  color: var(--note);
}

.page-about .about-block__title {
  margin: 0 0 12px;
  font-family: var(--font-head);
  font-size: clamp(21px, 2.7vw, 29px);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -.01em;
  color: var(--paper);
}

.page-about .about-block p {
  margin: 0 0 16px;
  font-size: 15px;
  line-height: 1.72;
  color: var(--body-text);
}

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

.page-about .about-block__link {
  display: inline-block;
  font-size: 14px;
  font-weight: 700;
  color: var(--turf);
  text-decoration: none;
  border-bottom: 2px solid currentColor;
  padding-bottom: 2px;
}

.page-about .about-block__link:hover,
.page-about .about-block__link:focus-visible {
  color: var(--amber);
}

/* ---------- 时间轴 ---------- */
.page-about .about-city {
  margin: 0 0 clamp(30px, 5vw, 54px);
}

.page-about .timeline {
  --tl-gutter: 36px;
  position: relative;
  margin: 0;
  padding: 0 0 0 var(--tl-gutter);
  list-style: none;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 10px;
  bottom: 10px;
  width: 2px;
  background: var(--line);
}

.page-about .timeline__item {
  position: relative;
  padding-bottom: clamp(28px, 4vw, 42px);
}

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

.page-about .timeline__item::before {
  content: "";
  position: absolute;
  left: calc(-1 * var(--tl-gutter));
  top: 4px;
  width: 16px;
  height: 16px;
  background: var(--amber);
  box-shadow: 3px 3px 0 0 rgba(0, 0, 0, .5);
}

.page-about .timeline__item--past::before {
  background: var(--rock);
  border: 2px dashed var(--line);
  box-shadow: none;
}

.page-about .timeline__item:focus-visible {
  outline: 2px solid var(--turf);
  outline-offset: 6px;
}

.page-about .timeline__year {
  margin: 0 0 4px;
  font-family: var(--font-num);
  font-size: clamp(22px, 3.4vw, 32px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: .02em;
  color: var(--turf);
  font-variant-numeric: tabular-nums;
}

.page-about .timeline__title {
  margin: 0 0 8px;
  font-family: var(--font-head);
  font-size: 19px;
  font-weight: 800;
  color: var(--paper);
}

.page-about .timeline__desc {
  margin: 0;
  max-width: 60ch;
  font-size: 15px;
  line-height: 1.72;
  color: var(--body-text);
}

.page-about .timeline__extra {
  margin: 10px 0 0;
  max-width: 56ch;
  padding-left: 12px;
  border-left: 2px solid var(--violet);
  font-size: 13px;
  line-height: 1.62;
  color: var(--note);
}

/* ---------- 数据带 ---------- */
.page-about .about-band {
  margin: clamp(44px, 7vw, 92px) 0;
  padding: clamp(32px, 5vw, 58px) 0;
  background:
    repeating-linear-gradient(90deg, rgba(42, 51, 72, .6) 0 1px, transparent 1px 72px),
    var(--rock);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.page-about .databand {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(22px, 4vw, 36px);
}

.page-about .databand__cell {
  border-left: 2px solid var(--turf);
  padding-left: 16px;
}

.page-about .databand__cell:nth-child(2) {
  border-left-color: var(--amber);
}

.page-about .databand__cell:nth-child(3) {
  border-left-color: var(--violet);
}

.page-about .databand__num {
  display: block;
  font-family: var(--font-num);
  font-size: clamp(38px, 6.4vw, 66px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--paper);
  font-variant-numeric: tabular-nums;
  text-shadow: 4px 4px 0 rgba(0, 0, 0, .45);
}

.page-about .databand__label {
  display: block;
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.5;
  color: var(--note);
}

/* ---------- 合作伙伴 ---------- */
.page-about .about-partners__grid {
  display: grid;
  gap: clamp(22px, 4vw, 36px);
}

.page-about .about-partners__text {
  border-left: var(--about-rule) solid var(--turf);
  padding-left: var(--about-gutter);
}

.page-about .about-partners__text p {
  margin: 0 0 1.05em;
  max-width: 68ch;
  color: var(--body-text);
  line-height: 1.8;
}

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

.page-about .about-partners__cta {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  align-items: flex-start;
}

/* ---------- 响应式 ---------- */
@media (min-width: 760px) {
  .page-about .databand {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 900px) {
  .page-about .about-open__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: start;
  }

  .page-about .about-grid {
    grid-template-columns: minmax(0, 1fr) var(--about-aside-w);
    gap: clamp(32px, 5vw, 64px);
    align-items: start;
  }

  .page-about .about-aside {
    position: sticky;
    top: 96px;
  }

  .page-about .about-blocks__list {
    grid-template-columns: repeat(12, minmax(0, 1fr));
  }

  .page-about .about-block:nth-child(1) {
    grid-column: 1 / span 7;
  }

  .page-about .about-block:nth-child(2) {
    grid-column: 8 / span 5;
  }

  .page-about .about-block:nth-child(3) {
    grid-column: 1 / span 12;
  }

  .page-about .about-block--wide {
    display: flex;
    flex-wrap: wrap;
    align-items: flex-end;
    justify-content: space-between;
    gap: 24px;
  }

  .page-about .about-block--wide .about-block__body {
    flex: 1 1 60ch;
    min-width: 0;
  }

  .page-about .about-partners__grid {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: end;
    gap: clamp(28px, 5vw, 56px);
  }

  .page-about .about-partners__cta {
    flex-direction: column;
    align-items: stretch;
  }

  .page-about .timeline__extra {
    max-height: 0;
    margin-top: 0;
    opacity: 0;
    overflow: hidden;
    transition:
      max-height .38s var(--ease),
      margin-top .28s var(--ease),
      opacity .28s var(--ease);
  }

  .page-about .timeline__item:hover .timeline__extra,
  .page-about .timeline__item:focus .timeline__extra,
  .page-about .timeline__item:focus-within .timeline__extra {
    max-height: 220px;
    margin-top: 10px;
    opacity: 1;
  }
}

@media (min-width: 1180px) {
  .page-about .about-open__text {
    padding-left: 32px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .timeline__extra,
  .page-about .about-block,
  .page-about .databand__cell {
    transition: none;
  }

  .page-about .timeline__extra {
    max-height: none;
    margin-top: 10px;
    opacity: 1;
  }
}