.page-about {
  --about-gutter: clamp(18px, 4.5vw, 48px);
  --about-axis: 5px;
  --about-axis-lg: 144px;
  --about-col-lg: 120px;
  --about-gap-lg: 48px;
  --about-node-pad: 20px;
  background: var(--jj-deep);
  color: var(--jj-cream-86);
  overflow-x: clip;
}

/* ---------- 面包屑 ---------- */
.page-about .about-crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding-top: 26px;
  font-family: var(--jj-mono);
  font-size: 13px;
  letter-spacing: .04em;
  color: var(--jj-cream-55);
}

.page-about .about-crumbs a {
  color: var(--jj-cream-72);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color .22s var(--jj-ease), border-color .22s var(--jj-ease);
}

.page-about .about-crumbs a:hover,
.page-about .about-crumbs a:focus-visible {
  color: var(--jj-cyan);
  border-bottom-color: var(--jj-cyan);
}

.page-about .about-crumbs__sep {
  color: var(--jj-line);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding-top: clamp(24px, 4vw, 44px);
  padding-bottom: clamp(40px, 6vw, 84px);
}

.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(28px, 5vw, 52px);
  align-items: end;
}

.page-about .about-hero__lede {
  min-width: 0;
}

.page-about .about-hero__title {
  margin: 16px 0 0;
  font-family: var(--jj-display);
  font-weight: 800;
  font-size: clamp(36px, 8.4vw, 76px);
  line-height: 1.02;
  letter-spacing: -.015em;
  color: var(--jj-cream);
  text-wrap: balance;
}

.page-about .about-hero__text {
  margin: 22px 0 0;
  max-width: 56ch;
  font-family: var(--jj-body);
  font-size: clamp(16px, 1.9vw, 18px);
  line-height: 1.78;
  color: var(--jj-cream-72);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.page-about .about-hero__figure {
  margin: 0;
  border-radius: var(--jj-radius);
}

.page-about .about-hero__metrics {
  margin-top: clamp(34px, 5vw, 56px);
  padding-top: clamp(22px, 3vw, 32px);
  border-top: 1px solid var(--jj-rule);
}

/* ---------- 通用编号区 ---------- */
.page-about .section-index {
  display: inline-block;
  font-size: 13px;
  letter-spacing: .22em;
  color: var(--jj-cyan);
}

.page-about .about-timeline .section-head,
.page-about .about-lines .section-head,
.page-about .about-authors .section-head,
.page-about .about-coverage .section-head,
.page-about .about-local .section-head,
.page-about .about-coop .section-head {
  max-width: 72ch;
}

.page-about .section-lede {
  color: var(--jj-cream-72);
}

/* ---------- 时间线 ---------- */
.page-about .about-timeline__axis {
  position: relative;
  margin-top: clamp(28px, 4vw, 48px);
  padding-left: 26px;
}

.page-about .about-timeline__axis::before {
  content: "";
  position: absolute;
  left: var(--about-axis);
  top: 14px;
  bottom: 14px;
  width: 1px;
  background: linear-gradient(180deg,
    var(--jj-cyan) 0%,
    var(--jj-rule-strong) 46%,
    var(--jj-rule) 100%);
}

.page-about .about-node {
  position: relative;
  border-bottom: 1px solid rgba(110, 122, 116, .16);
}

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

.page-about .about-node__summary {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  row-gap: 4px;
  align-items: center;
  padding: 18px 40px 18px 0;
  cursor: pointer;
  list-style: none;
  outline: none;
}

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

.page-about .about-node__summary::marker {
  content: "";
}

.page-about .about-node__summary:focus-visible {
  outline: 2px solid var(--jj-cyan);
  outline-offset: 4px;
  border-radius: 6px;
}

.page-about .about-node__dot {
  position: absolute;
  left: 0;
  top: 26px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--jj-deep);
  border: 1px solid var(--jj-line);
  transition: background .28s var(--jj-ease),
    border-color .28s var(--jj-ease),
    box-shadow .28s var(--jj-ease);
}

.page-about .about-node__year {
  grid-column: 1;
  font-size: clamp(34px, 5.4vw, 46px);
  font-weight: 800;
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--jj-cream-55);
  transition: color .28s var(--jj-ease), transform .28s var(--jj-ease);
}

.page-about .about-node__label {
  grid-column: 1;
  font-size: clamp(18px, 2.2vw, 22px);
  font-weight: 500;
  line-height: 1.45;
  color: var(--jj-cream);
}

.page-about .about-node__chev {
  position: absolute;
  right: 8px;
  top: 50%;
  width: 11px;
  height: 11px;
  margin-top: -8px;
  border-right: 1.5px solid var(--jj-line);
  border-bottom: 1.5px solid var(--jj-line);
  transform: rotate(45deg);
  transition: transform .3s var(--jj-ease), border-color .3s var(--jj-ease);
}

.page-about .about-node[open] .about-node__dot {
  background: var(--jj-cyan);
  border-color: var(--jj-cyan);
  box-shadow: 0 0 0 6px rgba(56, 242, 194, .13);
}

.page-about .about-node[open] .about-node__year {
  color: var(--jj-cyan);
  transform: translateX(2px);
}

.page-about .about-node[open] .about-node__chev {
  transform: rotate(225deg);
  border-color: var(--jj-cyan);
}

.page-about .about-node__summary:hover .about-node__year {
  color: var(--jj-cyan);
}

.page-about .about-node__summary:hover .about-node__dot {
  border-color: var(--jj-cyan);
}

.page-about .about-node__body {
  padding: 0 0 22px 0;
}

.page-about .about-node__body p {
  margin: 0;
  max-width: 68ch;
  font-family: var(--jj-body);
  font-size: 16px;
  line-height: 1.78;
  color: var(--jj-cream-72);
}

/* ---------- 四条内容线 ---------- */
.page-about .about-lines__panel {
  margin-top: clamp(22px, 3.5vw, 36px);
}

.page-about .about-lines__filter {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  padding-bottom: 6px;
}

.page-about .about-lines__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 18px;
  margin-top: 26px;
}

.page-about .about-line {
  padding: 26px 24px 22px;
  border-radius: var(--jj-radius);
  transition: transform .26s var(--jj-ease), box-shadow .26s var(--jj-ease);
}

.page-about .about-line:hover {
  transform: translateY(-2px);
}

.page-about .about-line__no {
  margin: 0 0 10px;
  font-size: 12px;
  letter-spacing: .2em;
  color: var(--jj-cyan);
}

.page-about .about-line__title {
  margin: 0 0 12px;
  font-size: clamp(21px, 2.6vw, 26px);
  color: var(--jj-cream);
}

.page-about .about-line__text {
  margin: 0;
  font-family: var(--jj-body);
  font-size: 15.5px;
  line-height: 1.76;
  color: var(--jj-cream-72);
}

.page-about .about-line__meta {
  margin: 18px 0 0;
  padding-top: 14px;
  border-top: 1px dashed var(--jj-rule);
  font-size: 12.5px;
  letter-spacing: .06em;
  color: var(--jj-cream-55);
}

.page-about .about-lines__figure {
  margin: clamp(30px, 5vw, 52px) 0 0;
  border-radius: var(--jj-radius);
}

/* ---------- 作者与选题 ---------- */
.page-about .about-authors__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 22px;
  margin-top: clamp(24px, 4vw, 40px);
}

.page-about .about-authors__col {
  padding: 24px 22px;
  border-radius: var(--jj-radius);
  background: var(--jj-moss);
  border: 1px solid rgba(110, 122, 116, .22);
}

.page-about .about-authors__label {
  margin: 0 0 12px;
  font-size: 18px;
  color: var(--jj-cream);
}

.page-about .about-authors__text {
  margin: 0;
  font-family: var(--jj-body);
  font-size: 15.5px;
  line-height: 1.76;
  color: var(--jj-cream-72);
}

.page-about .about-authors__list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-authors__list li {
  position: relative;
  padding-left: 18px;
  margin-bottom: 10px;
  font-family: var(--jj-body);
  font-size: 15.5px;
  line-height: 1.7;
  color: var(--jj-cream-72);
}

.page-about .about-authors__list li:last-child {
  margin-bottom: 0;
}

.page-about .about-authors__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .7em;
  width: 7px;
  height: 1px;
  background: var(--jj-cyan);
}

/* ---------- 赛事覆盖 ---------- */
.page-about .about-coverage__inner {
  padding-top: 4px;
}

.page-about .about-coverage__bars {
  display: grid;
  gap: 18px;
  margin-top: clamp(24px, 4vw, 40px);
}

.page-about .about-coverage__bar {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 8px;
}

.page-about .about-coverage__bar-label {
  font-size: 13px;
  letter-spacing: .08em;
  color: var(--jj-cream-72);
}

.page-about .about-coverage__bar-track {
  display: block;
  height: 6px;
  border-radius: 999px;
  background: rgba(110, 122, 116, .28);
  overflow: hidden;
}

.page-about .about-coverage__bar-fill {
  display: block;
  height: 100%;
  width: var(--fill, 60%);
  border-radius: 999px;
  background: linear-gradient(90deg, rgba(56, 242, 194, .45), var(--jj-cyan));
}

.page-about .about-coverage__bar-fill--amber {
  background: linear-gradient(90deg, rgba(233, 169, 63, .4), var(--jj-amber));
}

.page-about .about-coverage__note {
  margin-top: clamp(26px, 4vw, 40px);
  padding: 24px 24px;
  border-radius: var(--jj-radius);
  border-left: 3px solid var(--jj-amber);
}

.page-about .about-coverage__note p {
  margin: 0;
  max-width: 70ch;
  font-family: var(--jj-body);
  font-size: 16px;
  line-height: 1.78;
  color: var(--jj-cream-86);
}

/* ---------- 团队与地域 ---------- */
.page-about .about-local__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 4vw, 46px);
  align-items: start;
  margin-top: clamp(24px, 4vw, 40px);
}

.page-about .about-local__text p {
  margin: 0 0 18px;
  max-width: 62ch;
  font-family: var(--jj-body);
  font-size: 16px;
  line-height: 1.78;
  color: var(--jj-cream-72);
}

.page-about .about-local__link {
  margin-top: 6px;
}

.page-about .about-local__figure {
  margin: 0;
  border-radius: var(--jj-radius);
}

/* ---------- 合作生态 ---------- */
.page-about .about-coop__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 18px;
  margin-top: clamp(24px, 4vw, 40px);
}

.page-about .about-coop__card {
  padding: 24px 22px;
  border-radius: var(--jj-radius);
  background: rgba(243, 238, 228, .05);
  border: 1px solid rgba(110, 122, 116, .26);
  transition: transform .26s var(--jj-ease), border-color .26s var(--jj-ease);
}

.page-about .about-coop__card:hover {
  transform: translateY(-2px);
  border-color: rgba(56, 242, 194, .5);
}

.page-about .about-coop__card-title {
  margin: 0 0 10px;
  font-size: 19px;
  color: var(--jj-cream);
}

.page-about .about-coop__card-text {
  margin: 0;
  font-family: var(--jj-body);
  font-size: 15.5px;
  line-height: 1.76;
  color: var(--jj-cream-72);
}

.page-about .about-coop__cta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(28px, 4vw, 42px);
}

/* ---------- 平板及以上 ---------- */
@media (min-width: 700px) {
  .page-about .about-lines__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-authors__grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px;
  }

  .page-about .about-coop__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 20px;
  }

  .page-about .about-coverage__bar {
    grid-template-columns: 190px minmax(0, 1fr);
    align-items: center;
    gap: 20px;
  }
}

/* ---------- 桌面 ---------- */
@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.18fr) minmax(0, .82fr);
    gap: clamp(40px, 5vw, 72px);
  }

  .page-about .about-local__grid {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr);
  }

  .page-about .about-coop__card--offset {
    transform: translateY(28px);
  }

  .page-about .about-coop__card--offset:hover {
    transform: translateY(26px);
  }
}

@media (min-width: 820px) {
  .page-about .about-timeline__axis {
    padding-left: 0;
  }

  .page-about .about-timeline__axis::before {
    left: var(--about-axis-lg);
  }

  .page-about .about-node__summary {
    grid-template-columns: var(--about-col-lg) minmax(0, 1fr);
    column-gap: var(--about-gap-lg);
    row-gap: 0;
    padding: var(--about-node-pad) 46px var(--about-node-pad) 0;
  }

  .page-about .about-node__year {
    grid-column: 1;
    grid-row: 1;
    text-align: right;
  }

  .page-about .about-node__label {
    grid-column: 2;
    grid-row: 1;
  }

  .page-about .about-node__dot {
    left: var(--about-axis-lg);
    top: 50%;
    transform: translate(-50%, -50%);
  }

  .page-about .about-node__dot {
    transform: translateX(-50%);
    top: 36px;
  }

  .page-about .about-node__body {
    padding: 0 46px 26px calc(var(--about-col-lg) + var(--about-gap-lg));
  }
}

/* ---------- 动效降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .about-node__year,
  .page-about .about-node__dot,
  .page-about .about-node__chev,
  .page-about .about-line,
  .page-about .about-coop__card {
    transition: none;
  }
}
<<<END>>>

.page-about {
  --fill: currentColor;
}