.page-about {
  --about-gap: clamp(40px, 6vw, 96px);
  --about-line: rgba(200, 212, 222, 0.18);
  --about-line-strong: rgba(200, 212, 222, 0.36);
  --about-dim: rgba(200, 212, 222, 0.82);
  background: var(--night-deep-blue);
  color: var(--chalk-white);
  font-family: var(--font-body);
  overflow-x: clip;
}

.page-about [id] {
  scroll-margin-top: 108px;
}

/* ---------- 面包屑 ---------- */
.page-about .crumbs {
  background: var(--stadium-navy);
  border-bottom: 1px solid var(--about-line);
}

.page-about .crumbs__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  margin: 0;
  padding: 12px 0;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
}

.page-about .crumbs__item + .crumbs__item::before {
  content: "/";
  margin-right: 8px;
  color: rgba(200, 212, 222, 0.42);
}

.page-about .crumbs__link {
  color: var(--about-dim);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 160ms var(--ease), border-color 160ms var(--ease);
}

.page-about .crumbs__link:hover {
  color: var(--neon-cyan);
  border-bottom-color: var(--neon-cyan);
}

.page-about .crumbs__current {
  color: var(--chalk-white);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(36px, 5vw, 76px) 0 0;
  background:
    linear-gradient(158deg, rgba(34, 224, 200, 0.09) 0%, rgba(11, 27, 43, 0) 52%),
    var(--night-deep-blue);
}

.page-about .about-hero__slice {
  position: absolute;
  top: -34%;
  right: -10%;
  width: 44%;
  height: 168%;
  background: rgba(34, 224, 200, 0.055);
  transform: rotate(13deg);
  pointer-events: none;
}

.page-about .about-hero__slice::after {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: 2px;
  background: linear-gradient(180deg, rgba(34, 224, 200, 0), rgba(34, 224, 200, 0.7), rgba(34, 224, 200, 0));
}

.page-about .about-hero__inner {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  gap: 18px;
  max-width: 900px;
  padding-bottom: clamp(28px, 4vw, 52px);
}

.page-about .about-hero__kicker {
  margin: 0;
  font-size: 12px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--neon-cyan);
}

.page-about .about-hero__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: var(--step-5);
  line-height: 1.02;
  letter-spacing: -0.015em;
  color: var(--chalk-white);
  text-wrap: balance;
}

.page-about .about-hero__lede {
  margin: 0;
  max-width: 60ch;
  font-size: var(--step-1);
  line-height: 1.78;
  color: var(--about-dim);
}

.page-about .about-hero__where {
  margin: 0;
  padding-top: 16px;
  border-top: 1px solid var(--about-line);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--cyan-tint);
}

.page-about .about-hero__figure {
  position: relative;
  z-index: 1;
  margin: 0;
  border-top: 4px solid var(--neon-cyan);
  overflow: hidden;
  background: var(--stadium-navy);
}

.page-about .about-hero__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 7 / 4;
  object-fit: cover;
}

.page-about .about-hero__caption {
  padding: 10px 0 0;
  font-size: 13px;
  line-height: 1.6;
  color: rgba(200, 212, 222, 0.66);
}

/* ---------- 主体框架：左索引 + 右长文 ---------- */
.page-about .about-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 36px;
  padding-top: clamp(44px, 6vw, 96px);
}

.page-about .about-index {
  align-self: start;
}

.page-about .about-index__label {
  margin: 0 0 14px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--neon-cyan);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--neon-cyan);
}

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

.page-about .about-index__link {
  display: grid;
  grid-template-columns: 28px minmax(0, 1fr);
  gap: 10px;
  align-items: baseline;
  padding: 10px 0;
  border-bottom: 1px solid var(--about-line);
  color: var(--about-dim);
  text-decoration: none;
  font-size: 14px;
  line-height: 1.4;
  transition: color 160ms var(--ease), border-color 160ms var(--ease), padding-left 160ms var(--ease);
}

.page-about .about-index__link:hover {
  color: var(--chalk-white);
  border-bottom-color: var(--neon-cyan);
  padding-left: 4px;
}

.page-about .about-index__num {
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--neon-cyan);
}

.page-about .about-scale {
  margin-top: 30px;
  padding-top: 16px;
  border-top: 1px solid var(--about-line);
}

.page-about .about-scale__label {
  margin: 0 0 12px;
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--track-orange);
}

.page-about .about-scale__list {
  display: grid;
  gap: 0;
  margin: 0;
  padding: 0;
  list-style: none;
  border-left: 2px solid var(--about-line);
}

.page-about .about-scale__item {
  position: relative;
  padding: 0 0 14px 18px;
  font-size: 13px;
  line-height: 1.45;
  color: rgba(200, 212, 222, 0.72);
}

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

.page-about .about-scale__dot {
  position: absolute;
  left: -5px;
  top: 5px;
  width: 8px;
  height: 8px;
  background: var(--night-deep-blue);
  border: 2px solid var(--neon-cyan);
}

/* ---------- 章节 ---------- */
.page-about .about-section {
  padding-top: clamp(44px, 6vw, 96px);
}

.page-about .about-section--first {
  padding-top: 0;
}

.page-about .about-section__head {
  max-width: 780px;
  margin-bottom: 26px;
  padding-top: 18px;
  border-top: 2px solid var(--neon-cyan);
}

.page-about .about-section__num {
  display: block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--neon-cyan);
}

.page-about .about-section__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: var(--step-3);
  line-height: 1.14;
  letter-spacing: -0.01em;
  color: var(--chalk-white);
  text-wrap: balance;
}

.page-about .about-subhead {
  margin: 36px 0 16px;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.14em;
  color: var(--scoreboard-yellow);
}

.page-about .about-prose {
  display: grid;
  gap: 18px;
  max-width: 68ch;
  font-size: var(--body-size);
  line-height: 1.78;
  color: var(--about-dim);
}

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

.page-about .about-note {
  max-width: 68ch;
  margin: 0 0 8px;
  font-size: var(--body-size);
  line-height: 1.78;
  color: var(--about-dim);
}

.page-about .about-inline-note {
  max-width: 66ch;
  margin: 24px 0 0;
  padding-left: 18px;
  border-left: 3px solid var(--track-orange);
  font-size: 15px;
  line-height: 1.74;
  color: rgba(200, 212, 222, 0.86);
}

.page-about .about-pull {
  max-width: 54ch;
  margin: 34px 0 0;
  padding: 6px 0 6px 22px;
  border-left: 4px solid var(--track-orange);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--step-2);
  line-height: 1.42;
  color: var(--chalk-white);
}

/* ---------- 数据小结块 ---------- */
.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin-bottom: 30px;
  border-top: 1px solid var(--about-line);
  border-left: 1px solid var(--about-line);
}

.page-about .about-stat {
  padding: 20px 16px;
  border-right: 1px solid var(--about-line);
  border-bottom: 1px solid var(--about-line);
  background: var(--stadium-navy);
}

.page-about .about-stat__value {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(26px, 3.4vw, 38px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0.02em;
  font-variant-numeric: tabular-nums;
  color: var(--scoreboard-yellow);
}

.page-about .about-stat__label {
  display: block;
  margin-top: 12px;
  font-size: 13px;
  line-height: 1.62;
  color: var(--about-dim);
}

/* ---------- 城市矩阵 ---------- */
.page-about .about-cities {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin: 0;
  padding: 1px;
  list-style: none;
  background: var(--about-line);
  border: 1px solid var(--about-line);
}

.page-about .about-city {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 18px 18px 20px;
  background: var(--night-deep-blue);
  transition: background 200ms var(--ease);
}

.page-about .about-city::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: var(--neon-cyan);
  transform: scaleY(0);
  transform-origin: top;
  transition: transform 220ms var(--ease);
}

.page-about .about-city:hover,
.page-about .about-city:focus-within {
  background: var(--stadium-navy);
}

.page-about .about-city:hover::before,
.page-about .about-city:focus-within::before {
  transform: scaleY(1);
}

.page-about .about-city__name {
  display: flex;
  align-items: baseline;
  gap: 10px;
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--step-2);
  line-height: 1.1;
  color: var(--chalk-white);
}

.page-about .about-city__index {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 400;
  letter-spacing: 0.08em;
  color: var(--neon-cyan);
}

.page-about .about-city__levels {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin: 0;
}

.page-about .about-city__tag {
  padding: 5px 9px;
  border: 1px solid var(--about-line-strong);
  font-size: 12px;
  line-height: 1.2;
  color: var(--about-dim);
  transition: color 200ms var(--ease), border-color 200ms var(--ease);
}

.page-about .about-city:hover .about-city__tag {
  border-color: rgba(34, 224, 200, 0.55);
  color: var(--chalk-white);
}

/* ---------- 赛事层级 ---------- */
.page-about .about-levels {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 24px;
}

.page-about .about-level {
  padding-top: 16px;
  border-top: 4px solid var(--neon-cyan);
}

.page-about .about-level--cyan { border-top-color: var(--neon-cyan); }
.page-about .about-level--orange { border-top-color: var(--track-orange); }
.page-about .about-level--yellow { border-top-color: var(--scoreboard-yellow); }
.page-about .about-level--mist { border-top-color: var(--line-mist); }

.page-about .about-level__name {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--step-1);
  line-height: 1.25;
  color: var(--chalk-white);
}

.page-about .about-level__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.72;
  color: var(--about-dim);
}

/* ---------- 时间线 ---------- */
.page-about .about-timeline {
  position: relative;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-timeline__item {
  position: relative;
  padding: 0 0 34px 30px;
}

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

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 7px;
  width: 9px;
  height: 9px;
  background: var(--neon-cyan);
  transform: rotate(45deg);
}

.page-about .about-timeline__item::after {
  content: "";
  position: absolute;
  left: 4px;
  top: 22px;
  bottom: 0;
  width: 2px;
  background: var(--about-line-strong);
}

.page-about .about-timeline__item:last-child::after {
  display: none;
}

.page-about .about-timeline__step {
  display: block;
  margin-bottom: 6px;
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--track-orange);
}

.page-about .about-timeline__title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--step-1);
  line-height: 1.3;
  color: var(--chalk-white);
}

.page-about .about-timeline__text {
  max-width: 62ch;
  margin: 0;
  font-size: 15px;
  line-height: 1.74;
  color: var(--about-dim);
}

/* ---------- 图文分栏 ---------- */
.page-about .about-split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 28px;
  margin-top: 26px;
}

.page-about .about-split__figure {
  margin: 0;
  border-top: 4px solid var(--track-orange);
  background: var(--stadium-navy);
  overflow: hidden;
}

.page-about .about-split__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
}

.page-about .about-split__caption {
  padding: 10px 14px 12px;
  font-size: 13px;
  line-height: 1.6;
  color: rgba(200, 212, 222, 0.66);
}

.page-about .about-roles {
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--about-line);
}

.page-about .about-role {
  display: grid;
  grid-template-columns: 84px minmax(0, 1fr);
  gap: 16px;
  padding: 16px 0;
  border-bottom: 1px solid var(--about-line);
}

.page-about .about-role__key {
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--neon-cyan);
}

.page-about .about-role__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.72;
  color: var(--about-dim);
}

/* ---------- 服务准则 ---------- */
.page-about .about-principles {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin: 0;
  padding: 1px;
  list-style: none;
  background: var(--about-line);
  border: 1px solid var(--about-line);
}

.page-about .about-principle {
  display: grid;
  grid-template-columns: 48px minmax(0, 1fr);
  gap: 14px;
  padding: 22px 18px;
  background: var(--stadium-navy);
}

.page-about .about-principle__index {
  font-size: 15px;
  line-height: 1.4;
  letter-spacing: 0.06em;
  color: var(--scoreboard-yellow);
}

.page-about .about-principle__title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--step-1);
  line-height: 1.3;
  color: var(--chalk-white);
}

.page-about .about-principle__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.74;
  color: var(--about-dim);
}

/* ---------- 结尾行动区 ---------- */
.page-about .about-cta {
  margin-top: clamp(52px, 7vw, 104px);
  padding: clamp(28px, 4vw, 52px) clamp(20px, 3vw, 48px);
  background:
    linear-gradient(120deg, rgba(34, 224, 200, 0.12) 0%, rgba(11, 27, 43, 0) 60%),
    var(--stadium-navy);
  border-top: 4px solid var(--neon-cyan);
}

.page-about .about-cta__title {
  max-width: 24ch;
  margin: 0 0 16px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: var(--step-3);
  line-height: 1.14;
  color: var(--chalk-white);
  text-wrap: balance;
}

.page-about .about-cta__text {
  max-width: 62ch;
  margin: 0 0 26px;
  font-size: var(--body-size);
  line-height: 1.78;
  color: var(--about-dim);
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.page-about .about-cta__links {
  margin: 20px 0 0;
}

.page-about .about-cta__link {
  color: var(--cyan-tint);
  text-decoration: none;
  font-size: 14px;
  border-bottom: 1px solid rgba(127, 243, 228, 0.4);
  transition: color 160ms var(--ease), border-color 160ms var(--ease);
}

.page-about .about-cta__link:hover {
  color: var(--neon-cyan);
  border-bottom-color: var(--neon-cyan);
}

.page-about .about-cta__contact {
  margin: 24px 0 0;
  padding-top: 16px;
  border-top: 1px solid var(--about-line);
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--cyan-tint);
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-role {
    grid-template-columns: 108px minmax(0, 1fr);
  }
}

@media (min-width: 760px) {
  .page-about .about-cities {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

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

  .page-about .about-timeline__item {
    display: grid;
    grid-template-columns: 110px minmax(0, 1fr);
    gap: 0 22px;
  }

  .page-about .about-timeline__step {
    margin-bottom: 0;
    padding-top: 8px;
  }
}

@media (min-width: 1000px) {
  .page-about .about-shell {
    grid-template-columns: 208px minmax(0, 1fr);
    gap: clamp(40px, 5vw, 80px);
  }

  .page-about .about-index {
    position: sticky;
    top: 92px;
  }

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

  .page-about .about-levels {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-split {
    grid-template-columns: 1.05fr 1fr;
    gap: 48px;
    align-items: start;
  }

  .page-about .about-split--reverse {
    grid-template-columns: 1fr 1.05fr;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-index__link,
  .page-about .about-city,
  .page-about .about-city::before,
  .page-about .about-city__tag,
  .page-about .about-cta__link,
  .page-about .crumbs__link {
    transition: none;
  }
}