.page-about {
  --ab-cut: 14px;
  --ab-cutw: 66px;
  --ab-track: 180px;
  --ab-track-gap: 44px;
  --ab-rail-line: 202px;
  padding-top: clamp(84px, 10vw, 118px);
  padding-bottom: clamp(40px, 6vw, 80px);
}

/* ---------- 面包屑 ---------- */
.page-about .ab-crumb {
  margin-bottom: clamp(18px, 2.6vw, 30px);
}
.page-about .ab-crumb .breadcrumb__list {
  gap: 10px;
}
.page-about .ab-crumb .breadcrumb__item {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--steel);
}
.page-about .ab-crumb .breadcrumb__item a {
  color: var(--sky);
  text-decoration: none;
}
.page-about .ab-crumb .breadcrumb__item a:hover {
  color: var(--sky-lift);
}
.page-about .ab-crumb .breadcrumb__item + .breadcrumb__item::before {
  content: "/";
  margin-right: 10px;
  color: var(--line);
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  padding-bottom: clamp(38px, 5.4vw, 74px);
}
.page-about .ab-hero__grid {
  display: grid;
  gap: clamp(30px, 4.6vw, 56px);
  align-items: end;
}
.page-about .ab-hero__lead .lede {
  margin-top: clamp(16px, 2.2vw, 24px);
  max-width: 40ch;
}
.page-about .ab-hero h1.display {
  margin: 14px 0 0;
}
.page-about .ab-hero__l1,
.page-about .ab-hero__l2 {
  display: block;
}
.page-about .ab-hero__l2 {
  color: var(--sky);
  padding-left: clamp(0px, 3vw, 46px);
}
.page-about .ab-hero__tags {
  margin-top: clamp(20px, 2.8vw, 30px);
}

.page-about .ab-version {
  position: relative;
  padding: 22px 24px 26px;
  border: 1px solid var(--line-sky);
  background:
    linear-gradient(158deg, rgba(59, 158, 219, 0.18) 0%, rgba(23, 167, 155, 0.08) 46%, rgba(8, 25, 42, 0) 78%);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--ab-cut)), calc(100% - var(--ab-cutw)) 100%, 0 100%);
}
.page-about .ab-version__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(66px, 13vw, 122px);
  font-weight: 200;
  line-height: 0.92;
  letter-spacing: -0.04em;
  color: var(--lava);
  font-variant-numeric: tabular-nums;
}
.page-about .ab-version__note {
  display: block;
  margin-top: 8px;
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--steel);
}

.page-about .ab-facts {
  margin: clamp(20px, 2.6vw, 28px) 0 0;
}
.page-about .ab-facts__row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  padding: 11px 0;
  border-top: 1px solid var(--line-soft);
}
.page-about .ab-facts__row dt {
  font-size: 13px;
  color: var(--steel);
  letter-spacing: 0.04em;
}
.page-about .ab-facts__row dd {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--snow);
  font-variant-numeric: tabular-nums;
}

/* ---------- 筛选条 ---------- */
.page-about .ab-board {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: linear-gradient(90deg, rgba(59, 158, 219, 0.08), rgba(8, 25, 42, 0) 62%);
}
.page-about .ab-board__inner {
  display: flex;
  flex-direction: column;
  gap: 14px;
  padding: 18px 0;
}
.page-about .ab-board__hint {
  margin: 0;
  font-size: 14px;
  color: var(--steel);
  letter-spacing: 0.03em;
}
.page-about .ab-filter {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
}
.page-about .ab-filter > input[type="radio"] {
  position: absolute;
  width: 1px;
  height: 1px;
  opacity: 0;
  pointer-events: none;
}
.page-about .ab-filter > label {
  display: inline-block;
  padding: 7px 15px;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--steel);
  cursor: pointer;
  transition: color 0.22s var(--ease), background 0.22s var(--ease), border-color 0.22s var(--ease);
}
.page-about .ab-filter > label:hover {
  color: var(--snow);
  border-color: var(--line-sky);
}
.page-about .ab-filter > input[type="radio"]:checked + label {
  color: var(--ink);
  background: var(--lava);
  border-color: var(--lava);
  font-weight: 700;
}
.page-about .ab-filter > input[type="radio"]:focus-visible + label {
  outline: 2px solid var(--sky);
  outline-offset: 2px;
}
.page-about .ab-filter .filter__count {
  margin-left: 4px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--steel);
}

/* ---------- 目录条 ---------- */
.page-about .ab-toc {
  margin-top: clamp(22px, 3vw, 34px);
}
.page-about .ab-toc__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
  border-top: 1px solid var(--line-soft);
}
.page-about .ab-toc__item a {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 11px 0;
  border-bottom: 1px solid var(--line-soft);
  color: var(--snow);
  text-decoration: none;
  font-size: 14px;
  transition: color 0.2s var(--ease), padding-left 0.24s var(--ease);
}
.page-about .ab-toc__item a:hover {
  color: var(--sky-lift);
  padding-left: 6px;
}
.page-about .ab-toc__n {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--lava);
}

/* ---------- 时间轴 ---------- */
.page-about .ab-tl {
  list-style: none;
  margin: clamp(28px, 4vw, 46px) 0 0;
  padding: 0;
}
.page-about .ab-tl__item {
  position: relative;
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  padding: clamp(24px, 3.4vw, 34px) 0 clamp(28px, 4vw, 44px);
  border-top: 1px solid var(--line-soft);
}
.page-about .ab-tl__item:first-child {
  border-top: 1px solid var(--line);
}
.page-about .ab-tl__item.is-hidden {
  display: none;
}
.page-about .ab-tl__rail {
  display: flex;
  align-items: baseline;
  gap: 12px;
}
.page-about .ab-tl__code {
  font-family: var(--font-mono);
  font-size: 36px;
  font-weight: 200;
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--snow);
  font-variant-numeric: tabular-nums;
}
.page-about .ab-tl__stage {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--steel);
}

.page-about .ab-card {
  position: relative;
  padding: clamp(20px, 2.8vw, 32px);
  background: var(--bg-2);
  border: 1px solid var(--line);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 14px), calc(100% - 66px) 100%, 0 100%);
}
.page-about .ab-card::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 56px;
  height: 1px;
  background: var(--lava);
  transform: rotate(12deg);
  transform-origin: 0 0;
}
.page-about .ab-card--paper {
  background: var(--paper);
  border-color: rgba(8, 25, 42, 0.16);
  color: var(--bg);
  box-shadow: var(--shadow);
}
.page-about .ab-card--paper::after {
  background: var(--lava);
}

.page-about .ab-card .index-num {
  display: inline-block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--lava);
}
.page-about .ab-card--paper .index-num {
  color: var(--sky-deep);
}
.page-about .ab-card__title {
  margin: 0 0 14px;
  font-family: var(--font-display);
  font-size: clamp(23px, 3.4vw, 38px);
  font-weight: 300;
  line-height: 1.28;
  letter-spacing: -0.01em;
  color: var(--snow);
}
.page-about .ab-card--paper .ab-card__title {
  color: var(--bg);
}
.page-about .ab-card p {
  margin: 0 0 14px;
  font-size: clamp(15px, 1.5vw, 16.5px);
  line-height: 1.78;
  color: rgba(247, 250, 252, 0.82);
  max-width: 62ch;
}
.page-about .ab-card p:last-child {
  margin-bottom: 0;
}
.page-about .ab-card--paper p {
  color: rgba(8, 25, 42, 0.82);
}
.page-about .ab-card__linkline {
  margin-top: 18px;
}
.page-about .ab-inline-link {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--sky-deep);
  text-decoration: none;
  border-bottom: 1px solid rgba(15, 95, 142, 0.42);
  padding-bottom: 2px;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
}
.page-about .ab-inline-link:hover {
  color: var(--lava);
  border-color: var(--lava);
}

.page-about .ab-vchips {
  margin-top: 20px;
}

/* ---------- 图文分栏 ---------- */
.page-about .ab-split {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(20px, 3vw, 32px);
  align-items: start;
}
.page-about .ab-fig {
  margin: 0;
}
.page-about .ab-fig img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  border: 1px solid var(--line);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 12px), calc(100% - 58px) 100%, 0 100%);
}
.page-about .ab-fig figcaption {
  margin-top: 10px;
  font-size: 12.5px;
  line-height: 1.6;
  letter-spacing: 0.03em;
  color: var(--steel);
}
.page-about .ab-card--paper .ab-fig figcaption {
  color: rgba(8, 25, 42, 0.55);
}

/* ---------- 数据条 ---------- */
.page-about .ab-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0;
  margin-top: clamp(20px, 2.6vw, 28px);
  border-top: 1px solid var(--line);
}
.page-about .ab-stat {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 16px 4px 14px;
  border-bottom: 1px solid var(--line-soft);
}
.page-about .ab-stat__n {
  font-family: var(--font-mono);
  font-size: clamp(30px, 5vw, 44px);
  font-weight: 200;
  line-height: 1;
  color: var(--sky);
  font-variant-numeric: tabular-nums;
}
.page-about .ab-stat__l {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--steel);
}

/* ---------- 赛区分布图 ---------- */
.page-about .ab-map {
  display: block;
  width: 100%;
  height: auto;
  margin-top: clamp(20px, 2.6vw, 30px);
  overflow: visible;
}
.page-about .ab-map__grid line {
  stroke: var(--line-soft);
  stroke-width: 1;
}
.page-about .ab-map__trace {
  fill: none;
  stroke: var(--lake);
  stroke-width: 1.6;
  stroke-dasharray: 5 7;
  opacity: 0.8;
}
.page-about .ab-map__nodes circle {
  fill: var(--bg);
  stroke: var(--sky);
  stroke-width: 2.4;
}
.page-about .ab-map__nodes circle:nth-child(2),
.page-about .ab-map__nodes circle:nth-child(5) {
  stroke: var(--lake);
}
.page-about .ab-map__nodes circle:nth-child(4) {
  stroke: var(--lava);
  fill: var(--lava);
}

/* ---------- 延伸阅读 ---------- */
.page-about .ab-next {
  margin-top: clamp(38px, 5vw, 66px);
  padding-top: clamp(28px, 3.6vw, 44px);
  border-top: 1px solid var(--line);
}
.page-about .ab-next__title {
  margin: 0 0 clamp(16px, 2.2vw, 24px);
  font-family: var(--font-display);
  font-size: clamp(20px, 2.6vw, 28px);
  font-weight: 300;
  letter-spacing: 0.02em;
  color: var(--snow);
}
.page-about .ab-next__list {
  list-style: none;
  margin: 0;
  padding: 0;
}
.page-about .ab-next__item a {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: baseline;
  gap: 14px;
  padding: 15px 0;
  border-bottom: 1px solid var(--line-soft);
  text-decoration: none;
  transition: background 0.22s var(--ease), padding-left 0.26s var(--ease);
}
.page-about .ab-next__item a:hover {
  padding-left: 8px;
  background: rgba(59, 158, 219, 0.06);
}
.page-about .ab-next__n {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--lava);
}
.page-about .ab-next__t {
  font-size: clamp(14.5px, 1.6vw, 16.5px);
  line-height: 1.6;
  color: var(--snow);
}
.page-about .ab-next__k {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--steel);
  white-space: nowrap;
}

/* ---------- 桌面 ---------- */
@media (min-width: 820px) {
  .page-about .ab-board__inner {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
  }
  .page-about .ab-toc__list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    column-gap: clamp(18px, 2.4vw, 36px);
  }
  .page-about .ab-split--media-first {
    grid-template-columns: minmax(0, 0.92fr) minmax(0, 1.08fr);
  }
  .page-about .ab-split--media-after {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
  }
  .page-about .ab-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    column-gap: clamp(14px, 1.8vw, 28px);
  }
  .page-about .ab-stat {
    border-bottom: 0;
    padding: 18px 0 6px;
  }
}

@media (min-width: 960px) {
  .page-about .ab-hero__grid {
    grid-template-columns: minmax(0, 1.4fr) minmax(280px, 0.8fr);
  }
  .page-about .ab-tl__item {
    grid-template-columns: var(--ab-track) minmax(0, 1fr);
    gap: var(--ab-track-gap);
  }
  .page-about .ab-tl__item::before {
    content: "";
    position: absolute;
    top: 0;
    bottom: 0;
    left: var(--ab-rail-line);
    width: 1px;
    background: var(--line-soft);
  }
  .page-about .ab-tl__item::after {
    content: "";
    position: absolute;
    top: calc(clamp(24px, 3.4vw, 34px) + 14px);
    left: calc(var(--ab-rail-line) - 4.5px);
    width: 9px;
    height: 9px;
    border-radius: 50%;
    background: var(--bg);
    border: 1px solid var(--steel);
  }
  .page-about .ab-tl__rail {
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
    padding-top: clamp(24px, 3.4vw, 34px);
  }
  .page-about .ab-tl__code {
    font-size: clamp(48px, 5.2vw, 74px);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-toc__item a,
  .page-about .ab-next__item a,
  .page-about .ab-filter > label,
  .page-about .ab-inline-link {
    transition: none;
  }
}
</｜｜DSML｜｜ parameter>
</result>