.page-about {
  --about-line: #1E3145;
  --about-rule: rgba(255, 182, 39, 0.6);
  --about-paper-ink: #0D1A2B;
  --about-paper-sub: rgba(13, 26, 43, 0.72);
  display: block;
  padding-bottom: 5rem;
  background-image:
    radial-gradient(110% 55% at 88% -4%, rgba(34, 240, 220, 0.08), transparent 62%),
    radial-gradient(80% 45% at -6% 52%, rgba(255, 182, 39, 0.055), transparent 66%);
  background-repeat: no-repeat;
}

.page-about .crumbs {
  padding-top: 1.25rem;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  display: grid;
  gap: 2rem;
  padding: 1.75rem 0 3rem;
}

.page-about .about-hero__eyebrow {
  display: inline-block;
  margin: 0 0 1rem;
}

.page-about .about-hero h1 {
  margin: 0 0 1.25rem;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(2.1rem, 8vw, 3.9rem);
  line-height: 1.08;
  letter-spacing: -0.022em;
  max-width: 18ch;
}

.page-about .about-hero__lede {
  margin: 0;
  max-width: 38rem;
  font-size: 1.0625rem;
  line-height: 1.85;
  color: rgba(244, 234, 218, 0.78);
}

.page-about .about-hero__stats {
  display: flex;
  flex-wrap: wrap;
  gap: 1.25rem 2.5rem;
  margin-top: 2rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--about-line);
}

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

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

/* ---------- 章节骨架 ---------- */
.page-about .about-chapter {
  position: relative;
  padding: 0 0 2.75rem 1.25rem;
  margin: 0 0 2.75rem;
  border-left: 2px solid var(--about-line);
}

.page-about .about-chapter::after {
  content: "";
  position: absolute;
  left: 1.25rem;
  bottom: 1.25rem;
  width: 64px;
  height: 2px;
  background: var(--about-rule);
}

.page-about .about-chapter--last {
  margin-bottom: 0;
}

.page-about .about-chapter__head {
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
  margin-bottom: 1.25rem;
}

.page-about .about-chapter__num {
  flex: none;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(1.75rem, 5.5vw, 2.6rem);
  line-height: 1;
  letter-spacing: 0.02em;
  color: rgba(126, 147, 168, 0.5);
}

.page-about .about-chapter__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(1.35rem, 4.6vw, 2rem);
  line-height: 1.28;
  letter-spacing: -0.012em;
}

.page-about .about-chapter__lede {
  margin: 0 0 1.5rem;
  max-width: 40rem;
  font-size: 1rem;
  line-height: 1.8;
  color: rgba(244, 234, 218, 0.76);
}

.page-about .about-chapter__body p {
  color: rgba(244, 234, 218, 0.8);
}

.page-about .about-chapter__body p + p {
  margin-top: 1rem;
}

/* ---------- 阶段跳转 ---------- */
.page-about .about-jump {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 0.65rem;
  margin: 0 0 1.75rem;
}

.page-about .about-jump a {
  display: inline-block;
  padding: 0.4rem 0.95rem;
  border: 1px solid var(--about-line);
  border-radius: 999px;
  font-size: 0.875rem;
  line-height: 1.5;
  color: rgba(244, 234, 218, 0.86);
  text-decoration: none;
  transition: color 0.2s var(--ease-out), border-color 0.2s var(--ease-out), background-color 0.2s var(--ease-out);
}

.page-about .about-jump a:hover,
.page-about .about-jump a:focus-visible {
  color: var(--cyan);
  border-color: var(--cyan);
  background: rgba(34, 240, 220, 0.08);
}

/* ---------- 赛季四阶段 ---------- */
.page-about .about-stages {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1.75rem;
}

.page-about .about-stages__item {
  position: relative;
  padding-left: 1.4rem;
  scroll-margin-top: calc(var(--shell-top) + 1.5rem);
}

.page-about .about-stages__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.55rem;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 0 4px rgba(34, 240, 220, 0.14);
}

.page-about .about-stages__item h3 {
  margin: 0.65rem 0 0.5rem;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.1rem;
  line-height: 1.42;
}

.page-about .about-stages__item p {
  margin: 0;
  max-width: 40rem;
  font-size: 0.9688rem;
  line-height: 1.8;
  color: rgba(244, 234, 218, 0.75);
}

/* ---------- 团队与环形图 ---------- */
.page-about .about-team {
  display: grid;
  gap: 2rem;
  margin: 1.75rem 0 0;
}

.page-about .about-team__chart {
  margin: 0;
  text-align: center;
}

.page-about .about-ring {
  display: block;
  width: min(220px, 68vw);
  height: auto;
  margin: 0 auto;
}

.page-about .about-ring path {
  fill: none;
  stroke-width: 16;
  stroke-linecap: butt;
  transition: stroke-width 0.2s var(--ease-out), opacity 0.2s var(--ease-out);
}

.page-about .about-ring__seg:nth-of-type(1) path { stroke: var(--cyan); }
.page-about .about-ring__seg:nth-of-type(2) path { stroke: var(--amber); }
.page-about .about-ring__seg:nth-of-type(3) path { stroke: var(--haze); }
.page-about .about-ring__seg:nth-of-type(4) path { stroke: var(--cyan); opacity: 0.62; }
.page-about .about-ring__seg:nth-of-type(5) path { stroke: var(--amber); opacity: 0.62; }
.page-about .about-ring__seg:nth-of-type(6) path { stroke: var(--haze); opacity: 0.62; }

.page-about .about-ring__seg:hover path {
  stroke-width: 22;
  opacity: 1;
}

.page-about .about-ring__num {
  font-family: var(--font-mono);
  font-size: 30px;
  font-weight: 700;
  fill: var(--paper);
}

.page-about .about-ring__cap {
  font-family: var(--font-body);
  font-size: 12px;
  fill: var(--haze);
}

.page-about .about-team__chart figcaption {
  margin-top: 0.85rem;
  font-size: 0.8125rem;
  letter-spacing: 0.04em;
  color: var(--haze);
}

.page-about .about-groups {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.75rem;
  align-content: start;
}

.page-about .about-groups li {
  display: grid;
  grid-template-columns: 2.5rem 1fr;
  gap: 0.5rem;
  padding-bottom: 0.7rem;
  border-bottom: 1px solid var(--about-line);
  font-size: 0.9375rem;
  line-height: 1.65;
  color: rgba(244, 234, 218, 0.82);
}

.page-about .about-groups span {
  font-family: var(--font-mono);
  font-weight: 600;
  color: rgba(126, 147, 168, 0.9);
}

.page-about .about-team__figure {
  margin: 2rem 0 0;
  border-radius: var(--radius-md);
  overflow: hidden;
}

.page-about .about-team__figure img,
.page-about .about-sources__figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}

/* ---------- 协作生态配图 ---------- */
.page-about .about-sources__figure {
  margin: 2rem 0 0;
  border-radius: var(--radius-md);
  overflow: hidden;
}

/* ---------- 服务规模 ---------- */
.page-about .about-scale {
  margin-top: 0.5rem;
  padding: 2rem 1.5rem;
  border-radius: var(--radius-lg);
}

.page-about .about-scale__figures {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem 3.5rem;
}

.page-about .about-scale__num {
  display: block;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(2.25rem, 8vw, 3.25rem);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--about-paper-ink);
}

.page-about .about-scale__num em {
  font-style: normal;
  font-size: 0.44em;
  margin-left: 0.12em;
}

.page-about .about-scale__label {
  display: block;
  margin-top: 0.55rem;
  font-size: 0.875rem;
  letter-spacing: 0.03em;
  color: var(--about-paper-sub);
}

.page-about .about-scale__text {
  margin: 1.75rem 0 0;
  max-width: 38rem;
  font-size: 1rem;
  line-height: 1.85;
  color: var(--about-paper-sub);
}

/* ---------- 版本演进 ---------- */
.page-about .about-track {
  list-style: none;
  margin: 1.5rem 0 0;
  padding: 0;
  display: grid;
  gap: 1rem;
}

.page-about .about-track li {
  padding: 1.1rem 1.25rem;
  border: 1px solid var(--about-line);
  border-radius: var(--radius-md);
  background: var(--board);
  transition: border-color 0.2s var(--ease-out), transform 0.2s var(--ease-out);
}

.page-about .about-track li:hover {
  border-color: rgba(34, 240, 220, 0.55);
  transform: translateY(-2px);
}

.page-about .about-track p {
  margin: 0.7rem 0 0;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: rgba(244, 234, 218, 0.78);
}

/* ---------- 下一步 ---------- */
.page-about .about-next {
  display: grid;
  gap: 1rem;
  margin-top: 1.5rem;
}

.page-about .about-next__link {
  display: block;
  padding: 1.25rem;
  border-radius: var(--radius-md);
  text-decoration: none;
  color: inherit;
}

.page-about .about-next__name {
  display: block;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.0625rem;
  letter-spacing: -0.01em;
}

.page-about .about-next__desc {
  display: block;
  margin-top: 0.6rem;
  font-size: 0.9375rem;
  line-height: 1.7;
  color: rgba(244, 234, 218, 0.72);
}

.page-about .about-next__link:hover .about-next__name,
.page-about .about-next__link:focus-visible .about-next__name {
  color: var(--cyan);
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .about-chapter {
    padding-left: 2rem;
  }

  .page-about .about-chapter::after {
    left: 2rem;
  }

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

  .page-about .about-team__figure {
    margin-top: 2.5rem;
  }
}

@media (min-width: 960px) {
  .page-about {
    padding-bottom: 6.5rem;
  }

  .page-about .about-hero {
    grid-template-columns: minmax(0, 1.02fr) minmax(0, 0.98fr);
    align-items: center;
    gap: 3.5rem;
    padding: 2.25rem 0 4rem;
  }

  .page-about .about-chapter {
    padding-left: 3rem;
    margin-bottom: 3.5rem;
  }

  .page-about .about-chapter::after {
    left: 3rem;
  }

  .page-about .about-chapter__head {
    gap: 1.25rem;
  }

  .page-about .about-team {
    grid-template-columns: minmax(0, 260px) minmax(0, 1fr);
    align-items: center;
    gap: 3rem;
  }

  .page-about .about-groups {
    gap: 0.85rem;
  }

  .page-about .about-track {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 1.25rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-jump a,
  .page-about .about-track li,
  .page-about .about-ring path {
    transition: none;
  }

  .page-about .about-track li:hover {
    transform: none;
  }
}