.page-about {
  --about-lane-gap: clamp(12px, 1.6vw, 18px);
  --about-sticky: calc(var(--bar-h) + 22px);
  color: var(--c-mist);
}

/* ---------- 顶部上下文 ---------- */
.page-about .about-top {
  padding-top: clamp(72px, 8vw, 96px);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding-block: clamp(20px, 4vw, 48px) clamp(40px, 6vw, 84px);
  background:
    radial-gradient(120% 90% at 88% 8%, rgba(255, 90, 31, 0.14), transparent 58%),
    radial-gradient(90% 70% at 4% 96%, rgba(53, 240, 192, 0.08), transparent 60%);
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(24px, 4vw, 52px);
  align-items: center;
}

.page-about .about-hero h1 {
  margin: 12px 0 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(36px, 6.4vw, 74px);
  line-height: 0.98;
  letter-spacing: -0.02em;
  color: var(--c-mist);
  max-width: 14ch;
}

.page-about .about-hero__lede {
  margin: 18px 0 0;
  max-width: 54ch;
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.8;
  color: var(--c-steel);
}

.page-about .about-facts {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 30px;
  margin: 28px 0 0;
  padding: 0;
  list-style: none;
  font-size: 13px;
  letter-spacing: 0.02em;
  color: var(--c-steel);
}

.page-about .about-facts li {
  display: flex;
  align-items: baseline;
  gap: 7px;
}

.page-about .about-facts .num {
  font-size: 21px;
  font-weight: 700;
  color: var(--c-neon);
}

.page-about .about-hero__visual {
  width: 100%;
  max-width: 520px;
  justify-self: stretch;
}

.page-about .about-orbit {
  display: block;
  width: 100%;
  height: auto;
  overflow: visible;
}

.page-about .about-orbit__path {
  fill: none;
  stroke: url(#aboutArcGrad);
  stroke-width: 2;
  stroke-linecap: round;
}

.page-about .about-orbit__tick {
  stroke: var(--c-line);
  stroke-width: 1;
}

.page-about .about-orbit__dot {
  fill: var(--c-lava);
}

.page-about .about-orbit__dot--now {
  fill: var(--c-neon);
  filter: drop-shadow(0 0 9px rgba(53, 240, 192, 0.65));
}

/* ---------- 章节标题行 ---------- */
.page-about .section-head h2 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(26px, 3.8vw, 44px);
  line-height: 1.1;
  letter-spacing: -0.02em;
  color: var(--c-mist);
}

.page-about .section-head__lead {
  margin: 10px 0 0;
  max-width: 56ch;
  font-size: 15px;
  line-height: 1.75;
  color: var(--c-steel);
}

/* ---------- 时间轴 ---------- */
.page-about .about-timeline {
  position: relative;
  padding-block: clamp(40px, 6vw, 80px);
  border-top: 1px solid var(--c-line);
}

.page-about .about-timeline .section-head {
  margin-bottom: clamp(26px, 4vw, 48px);
}

.page-about .about-timeline__layout {
  display: grid;
  gap: 18px;
}

.page-about .about-rail__list {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 0 0 6px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: none;
  -webkit-overflow-scrolling: touch;
}

.page-about .about-rail__list::-webkit-scrollbar {
  display: none;
}

.page-about .about-rail__link {
  display: inline-block;
  white-space: nowrap;
  padding: 7px 13px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--c-steel);
  text-decoration: none;
  border: 1px solid var(--c-line);
  border-radius: 999px;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease), background-color 0.18s var(--ease);
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  color: var(--c-mist);
  border-color: var(--c-lava);
  background: rgba(255, 90, 31, 0.12);
  outline: none;
}

.page-about .about-stages {
  display: grid;
  gap: clamp(16px, 2.6vw, 32px);
  min-width: 0;
}

/* ---------- 阶段面板 ---------- */
.page-about .stage {
  position: relative;
  padding: clamp(20px, 3.2vw, 40px);
  background: linear-gradient(160deg, rgba(20, 49, 92, 0.92), rgba(6, 20, 40, 0.92));
  border: 1px solid var(--c-line);
  box-shadow: var(--shadow-soft);
  scroll-margin-top: var(--about-sticky);
  overflow: hidden;
}

.page-about .stage::after {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 84px;
  height: 84px;
  pointer-events: none;
  background: repeating-linear-gradient(115deg, rgba(255, 90, 31, 0.3) 0 1px, transparent 1px 13px);
  opacity: 0.75;
}

.page-about .stage__years {
  margin: 0;
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.09em;
  color: var(--c-neon);
}

.page-about .stage__years::before {
  content: "";
  width: 22px;
  height: 1px;
  background: var(--c-neon);
}

.page-about .stage__title {
  margin: 12px 0 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(23px, 3.1vw, 36px);
  line-height: 1.14;
  letter-spacing: -0.02em;
  color: var(--c-mist);
  max-width: 22ch;
}

.page-about .stage__body {
  margin: 14px 0 0;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--c-steel);
  max-width: 62ch;
}

.page-about .stage__body p + p {
  margin-top: 12px;
}

.page-about .stage__media {
  margin: 22px 0 0;
  border: 1px solid var(--c-line);
  overflow: hidden;
  background: var(--c-panel);
}

.page-about .stage__media img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  filter: saturate(0.82) contrast(1.06) brightness(0.92);
}

/* ---------- 团队泳道 ---------- */
.page-about .lane-grid {
  display: grid;
  gap: var(--about-lane-gap);
  margin-top: 22px;
}

.page-about .lane {
  padding: 15px 17px;
  background: rgba(10, 30, 60, 0.62);
  border: 1px solid var(--c-line);
  border-top: 2px solid var(--c-lava);
}

.page-about .lane > summary {
  display: flex;
  align-items: baseline;
  gap: 10px;
  cursor: pointer;
  list-style: none;
}

.page-about .lane > summary::-webkit-details-marker {
  display: none;
}

.page-about .lane > summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 15px;
  color: var(--c-steel);
  transition: color 0.18s var(--ease);
}

.page-about .lane[open] > summary::after {
  content: "\2212";
  color: var(--c-lava-soft);
}

.page-about .lane > summary:focus-visible {
  outline: 1px solid var(--c-neon);
  outline-offset: 3px;
}

.page-about .lane__index {
  font-size: 12px;
  color: var(--c-lava-soft);
}

.page-about .lane__name {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 19px;
  letter-spacing: -0.01em;
  color: var(--c-mist);
}

.page-about .lane__body {
  margin: 10px 0 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--c-steel);
}

/* ---------- 合作生态 ---------- */
.page-about .partner-grid {
  display: grid;
  gap: 14px;
  margin-top: 22px;
}

.page-about .partner-card {
  position: relative;
  padding: 22px 20px 20px;
  background: rgba(20, 49, 92, 0.55);
  border: 1px solid var(--c-line);
}

.page-about .partner-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 42px;
  height: 2px;
  background: var(--c-neon);
}

.page-about .partner-card__count {
  display: flex;
  align-items: baseline;
  gap: 6px;
  margin: 0;
}

.page-about .partner-card__count .num {
  font-size: clamp(34px, 5vw, 50px);
  font-weight: 700;
  line-height: 1;
  color: var(--c-mist);
}

.page-about .partner-card__unit {
  font-size: 14px;
  color: var(--c-steel);
}

.page-about .partner-card__title {
  margin: 12px 0 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 18px;
  letter-spacing: -0.01em;
  color: var(--c-lava-soft);
}

.page-about .partner-card__body {
  margin: 8px 0 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--c-steel);
}

/* ---------- 赛季节点 ---------- */
.page-about .about-seasons {
  position: relative;
  padding-block: clamp(40px, 6vw, 80px);
  border-top: 1px solid var(--c-line);
}

.page-about .about-seasons .section-head {
  margin-bottom: clamp(22px, 3.4vw, 40px);
}

.page-about .season-banner {
  margin: 0;
  border: 1px solid var(--c-line);
  overflow: hidden;
  background: var(--c-panel);
}

.page-about .season-banner img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  filter: saturate(0.78) brightness(0.82) contrast(1.08);
}

.page-about .season-metrics {
  display: grid;
  gap: 1px;
  margin: clamp(20px, 3vw, 32px) 0 0;
  padding: 0;
  list-style: none;
  background: var(--c-line);
  border: 1px solid var(--c-line);
}

.page-about .season-metric {
  display: grid;
  gap: 6px;
  padding: 18px 20px;
  background: var(--c-midnight);
}

.page-about .season-metric__value {
  font-size: 15px;
  font-weight: 700;
  color: var(--c-lava);
  letter-spacing: 0.02em;
}

.page-about .season-metric__text {
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--c-steel);
}

/* ---------- 内容标准 ---------- */
.page-about .about-standards {
  padding-block: clamp(40px, 6vw, 80px);
  background: linear-gradient(180deg, rgba(6, 20, 40, 0.96), rgba(10, 30, 60, 0.96));
  border-top: 1px solid var(--c-line);
}

.page-about .about-standards .section-head {
  margin-bottom: clamp(22px, 3.4vw, 40px);
}

.page-about .standard-grid {
  display: grid;
  gap: 14px;
}

.page-about .standard {
  position: relative;
  padding: 22px 20px;
  border: 1px solid var(--c-line);
  background: rgba(20, 49, 92, 0.35);
}

.page-about .standard__num {
  display: block;
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--c-neon);
}

.page-about .standard__title {
  margin: 10px 0 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 20px;
  line-height: 1.2;
  letter-spacing: -0.01em;
  color: var(--c-mist);
}

.page-about .standard__body {
  margin: 10px 0 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--c-steel);
}

.page-about .inline-link {
  color: var(--c-lava-soft);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

.page-about .inline-link:hover,
.page-about .inline-link:focus-visible {
  color: var(--c-neon);
}

/* ---------- 延伸阅读 ---------- */
.page-about .about-next {
  padding-block: clamp(40px, 6vw, 80px);
  border-top: 1px solid var(--c-line);
}

.page-about .about-next .section-head {
  margin-bottom: clamp(20px, 3vw, 34px);
}

.page-about .next-grid {
  display: grid;
  gap: 14px;
}

.page-about .next-card {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 22px 20px;
  text-decoration: none;
  border: 1px solid var(--c-line);
  background: rgba(10, 30, 60, 0.5);
  transition: border-color 0.2s var(--ease), transform 0.2s var(--ease), background-color 0.2s var(--ease);
}

.page-about .next-card:hover,
.page-about .next-card:focus-visible {
  border-color: var(--c-lava);
  background: rgba(255, 90, 31, 0.09);
  transform: translateY(-2px);
  outline: none;
}

.page-about .next-card__kicker {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--c-steel);
}

.page-about .next-card__title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 19px;
  line-height: 1.25;
  letter-spacing: -0.01em;
  color: var(--c-mist);
}

.page-about .next-card__go {
  margin-top: auto;
  font-size: 13px;
  color: var(--c-lava);
}

.page-about .next-card:hover .next-card__go,
.page-about .next-card:focus-visible .next-card__go {
  color: var(--c-neon);
}

/* ---------- 平板与桌面 ---------- */
@media (min-width: 700px) {
  .page-about .lane-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

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

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

  .page-about .season-metric {
    grid-template-columns: minmax(0, 150px) minmax(0, 1fr);
    align-items: baseline;
    gap: 18px;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: 7fr 5fr;
  }

  .page-about .about-hero__visual {
    justify-self: end;
  }

  .page-about .section-head {
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    gap: clamp(24px, 4vw, 56px);
    align-items: end;
  }

  .page-about .section-head__lead {
    margin: 0;
    justify-self: start;
  }
}

@media (min-width: 1000px) {
  .page-about .about-timeline__layout {
    grid-template-columns: 132px minmax(0, 1fr);
    gap: clamp(28px, 4vw, 56px);
  }

  .page-about .about-rail {
    position: sticky;
    top: var(--about-sticky);
    align-self: start;
  }

  .page-about .about-rail__list {
    flex-direction: column;
    gap: 0;
    padding: 0;
    overflow: visible;
    border-left: 1px solid var(--c-line);
  }

  .page-about .about-rail__link {
    display: block;
    padding: 13px 0 13px 20px;
    border: 0;
    border-radius: 0;
    background: none;
    position: relative;
    font-size: 12.5px;
  }

  .page-about .about-rail__link::before {
    content: "";
    position: absolute;
    left: -3px;
    top: 50%;
    width: 5px;
    height: 5px;
    margin-top: -2px;
    border-radius: 50%;
    background: var(--c-line);
    transition: background-color 0.18s var(--ease), transform 0.18s var(--ease);
  }

  .page-about .about-rail__link:hover,
  .page-about .about-rail__link:focus-visible {
    background: none;
    color: var(--c-lava-soft);
    border-color: transparent;
  }

  .page-about .about-rail__link:hover::before,
  .page-about .about-rail__link:focus-visible::before {
    background: var(--c-lava);
    transform: scale(1.5);
  }

  .page-about .stage--split .stage__inner {
    display: grid;
    grid-template-columns: minmax(0, 1.12fr) minmax(0, 0.88fr);
    gap: clamp(22px, 3.2vw, 44px);
    align-items: start;
  }

  .page-about .stage--split .stage__media {
    margin-top: 0;
  }

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

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

@media (min-width: 1240px) {
  .page-about .lane-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .stage {
    padding: clamp(28px, 3.6vw, 46px);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .next-card,
  .page-about .about-rail__link,
  .page-about .about-rail__link::before {
    transition: none;
  }

  .page-about .next-card:hover,
  .page-about .next-card:focus-visible {
    transform: none;
  }
}