.page-about {
  --about-chunk-accent: var(--autumn);
  --about-stage: var(--muted);
  display: block;
}

.page-about .about-hero {
  padding: clamp(20px, 3.5vw, 40px) 0 clamp(36px, 5vw, 64px);
  background:
    radial-gradient(1100px 460px at 88% -14%, rgba(224, 168, 46, .18), transparent 62%),
    radial-gradient(760px 420px at 2% 104%, rgba(59, 130, 196, .14), transparent 60%);
}

.page-about .about-hero__frame {
  position: relative;
  border: 1px solid var(--line);
  border-radius: var(--r-xl);
  background: rgba(255, 255, 255, .55);
  padding: clamp(20px, 3.4vw, 44px);
  box-shadow: var(--shadow-island);
  overflow: hidden;
}

.page-about .about-hero__frame::before {
  content: "";
  position: absolute;
  top: 0;
  left: clamp(20px, 3.4vw, 44px);
  right: clamp(20px, 3.4vw, 44px);
  height: 5px;
  border-radius: 0 0 4px 4px;
  background: linear-gradient(90deg,
    var(--spring) 0 25%,
    var(--summer) 25% 50%,
    var(--autumn) 50% 75%,
    var(--winter) 75% 100%);
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(20px, 3vw, 42px);
  align-items: center;
  margin-top: clamp(16px, 2.4vw, 26px);
}

.page-about .about-hero h1 {
  font-size: clamp(1.9rem, 4.6vw, 3.4rem);
  line-height: 1.12;
  letter-spacing: -.02em;
  margin: .35em 0 .55em;
}

.page-about .about-hero__lead {
  margin: 0;
  max-width: 42ch;
  font-size: clamp(1rem, 1.4vw, 1.1rem);
  line-height: 1.85;
  color: var(--ink);
}

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

.page-about .about-facts {
  list-style: none;
  margin: clamp(24px, 3.4vw, 38px) 0 0;
  padding: clamp(18px, 2.6vw, 26px) 0 0;
  border-top: 1px solid var(--line);
  display: grid;
  gap: clamp(14px, 2.4vw, 24px);
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.page-about .about-facts__item {
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-width: 0;
}

.page-about .about-facts__num {
  font-family: var(--font-mono);
  font-size: clamp(1.55rem, 2.8vw, 2.15rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.03em;
  color: var(--ink);
}

.page-about .about-facts__label {
  font-size: .8rem;
  line-height: 1.55;
  color: var(--muted);
}

/* ---------- 主体：左窄右宽 ---------- */

.page-about .about-body {
  padding-bottom: clamp(48px, 7vw, 96px);
}

.page-about .about-body__grid {
  display: grid;
  gap: clamp(22px, 3.4vw, 48px);
}

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

.page-about .anchor-nav {
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  background: rgba(255, 255, 255, .58);
  padding: 16px 14px;
}

.page-about .about-side__label {
  margin: 0 0 10px 12px;
  font-size: .7rem;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .anchor-nav ol {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 2px;
}

.page-about .anchor-nav a {
  display: block;
  padding: 9px 12px;
  border-radius: var(--r-sm);
  border-left: 3px solid transparent;
  color: var(--ink);
  font-size: .9rem;
  line-height: 1.4;
  text-decoration: none;
  transition: background-color 180ms var(--ease), border-color 180ms var(--ease);
}

.page-about .anchor-nav a:hover {
  background: rgba(16, 24, 32, .06);
}

.page-about .anchor-nav .is-current a {
  background: rgba(242, 107, 56, .12);
  border-left-color: var(--summer);
  font-weight: 700;
}

/* ---------- 正文区块 ---------- */

.page-about .about-flow {
  min-width: 0;
  display: grid;
  gap: clamp(18px, 2.6vw, 30px);
}

.page-about .about-chunk {
  border-radius: var(--r-xl);
  padding: clamp(22px, 3.2vw, 44px);
  background: var(--paper);
  scroll-margin-top: 120px;
}

.page-about .about-chunk--spring { --about-chunk-accent: var(--spring); background: var(--paper); }
.page-about .about-chunk--summer { --about-chunk-accent: var(--summer); background: var(--paper-2); }
.page-about .about-chunk--autumn { --about-chunk-accent: var(--autumn); background: var(--paper); }
.page-about .about-chunk--winter { --about-chunk-accent: var(--winter); background: var(--paper-2); }
.page-about .about-chunk--ink { --about-chunk-accent: var(--winter-deep); background: var(--paper); }

.page-about .about-chunk__mark {
  display: block;
  width: 52px;
  height: 5px;
  border-radius: 3px;
  margin-bottom: 18px;
  background: var(--about-chunk-accent);
}

.page-about .about-chunk h2 {
  font-size: clamp(1.35rem, 2.6vw, 1.95rem);
  line-height: 1.28;
  letter-spacing: -.02em;
  margin: 0;
}

.page-about .about-chunk .prose {
  max-width: 660px;
}

.page-about .about-chunk .prose p {
  margin-top: 16px;
}

/* ---------- 赛段时间轴 ---------- */

.page-about .season-line {
  margin-top: clamp(24px, 3.6vw, 40px);
}

.page-about .season-line__svg {
  display: block;
  width: 100%;
  height: auto;
}

.page-about .season-line__stages {
  list-style: none;
  margin: clamp(22px, 3vw, 32px) 0 0;
  padding: 0;
  display: grid;
  gap: clamp(16px, 2.4vw, 22px);
}

.page-about .about-stage {
  border-left: 3px solid var(--about-stage);
  padding-left: 16px;
  min-width: 0;
}

.page-about .about-stage--spring { --about-stage: var(--spring); }
.page-about .about-stage--summer { --about-stage: var(--summer); }
.page-about .about-stage--autumn { --about-stage: var(--autumn); }
.page-about .about-stage--winter { --about-stage: var(--winter); }

.page-about .about-stage h3 {
  margin: 10px 0 8px;
  font-size: 1rem;
  line-height: 1.4;
  letter-spacing: -.01em;
}

.page-about .about-stage p {
  margin: 0;
  font-size: .875rem;
  line-height: 1.72;
  color: var(--muted);
}

.page-about .about-seasons-media {
  margin: clamp(24px, 3.4vw, 38px) 0 0;
}

/* ---------- 合作方 ---------- */

.page-about .about-partners {
  display: grid;
  gap: 16px;
  margin-top: clamp(22px, 3vw, 32px);
}

.page-about .about-partners__card {
  border: 1px solid var(--line);
  border-left: 5px solid var(--winter);
  border-radius: var(--r-lg);
  padding: clamp(20px, 2.6vw, 28px);
  background: rgba(255, 255, 255, .68);
  min-width: 0;
}

.page-about .about-partners__card--school {
  border-left-color: var(--summer);
}

.page-about .about-partners__num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(1.9rem, 3.6vw, 2.6rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.03em;
  color: var(--ink);
}

.page-about .about-partners__name {
  margin: 10px 0 8px;
  font-size: 1rem;
  line-height: 1.4;
}

.page-about .about-partners__desc {
  margin: 0;
  font-size: .875rem;
  line-height: 1.72;
  color: var(--muted);
}

/* ---------- 运营中心 ---------- */

.page-about .about-loc {
  display: grid;
  gap: clamp(20px, 3vw, 34px);
  margin-top: 8px;
}

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

/* ---------- 下一步 ---------- */

.page-about .about-next {
  padding: 0 0 clamp(48px, 7vw, 96px);
}

.page-about .about-next__panel {
  display: grid;
  gap: clamp(20px, 3vw, 36px);
  border-radius: var(--r-xl);
  padding: clamp(24px, 4vw, 52px);
  background: var(--ink);
  color: var(--paper);
}

.page-about .about-next__panel h2 {
  margin: 10px 0 12px;
  font-size: clamp(1.45rem, 3vw, 2.05rem);
  line-height: 1.25;
  letter-spacing: -.02em;
  color: var(--white);
}

.page-about .about-next__panel p {
  margin: 0;
  max-width: 46ch;
  line-height: 1.8;
  color: rgba(246, 241, 231, .78);
}

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

.page-about .about-next__actions .btn--ghost {
  color: var(--paper);
  border: 1px solid var(--line-invert);
  background: transparent;
}

/* ---------- 响应式 ---------- */

.page-about .media__img {
  max-width: 100%;
}

@media (min-width: 640px) {
  .page-about .about-facts {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 720px) {
  .page-about .season-line__stages {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

@media (min-width: 860px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, .85fr);
  }

  .page-about .about-loc {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr);
    align-items: start;
  }

  .page-about .about-next__panel {
    grid-template-columns: minmax(0, 1.25fr) minmax(0, .85fr);
    align-items: center;
  }
}

@media (min-width: 1024px) {
  .page-about .about-facts {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }

  .page-about .about-body__grid {
    grid-template-columns: 236px minmax(0, 1fr);
    align-items: start;
  }

  .page-about .about-side {
    position: sticky;
    top: 108px;
  }

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

@media (max-width: 1023px) {
  .page-about .anchor-nav ol {
    grid-auto-flow: column;
    grid-auto-columns: max-content;
    gap: 8px;
    overflow-x: auto;
    padding-bottom: 4px;
    -webkit-overflow-scrolling: touch;
  }

  .page-about .anchor-nav a {
    border-left: 0;
    border-bottom: 3px solid transparent;
    white-space: nowrap;
  }

  .page-about .anchor-nav .is-current a {
    border-left-color: transparent;
    border-bottom-color: var(--summer);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .anchor-nav a {
    transition: none;
  }
}