.page-about {
  --about-gap: clamp(30px, 6vw, 76px);
  background: var(--bg);
  color: var(--white);
  overflow-x: clip;
}

/* ---------- 首屏 ---------- */
.page-about .hero {
  position: relative;
  padding-bottom: var(--about-gap);
}

.page-about .hero::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 66%;
  background:
    linear-gradient(115deg, rgba(124, 255, 138, 0.055) 0 41%, transparent 41.2%),
    radial-gradient(95% 125% at 94% 0%, rgba(226, 60, 60, 0.17), transparent 62%);
  pointer-events: none;
  z-index: 0;
}

.page-about .hero > * {
  position: relative;
  z-index: 1;
}

.page-about .hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 5vw, 48px);
  align-items: center;
  padding-top: clamp(18px, 3vw, 34px);
}

.page-about .hero__note {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--green);
  border-left: 3px solid var(--green);
  padding-left: 10px;
  line-height: 1.2;
}

.page-about .hero__title {
  margin: 16px 0 0;
  font-size: clamp(30px, 6.2vw, 58px);
  font-weight: 900;
  line-height: 1.06;
  letter-spacing: -0.015em;
  font-stretch: 85%;
}

.page-about .hero__sub {
  margin: 18px 0 0;
  max-width: 46ch;
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.78;
  color: var(--muted);
}

.page-about .hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.page-about .hero__art {
  position: relative;
  padding: 20px 0 0 20px;
}

.page-about .hero__art::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 62%;
  height: 58%;
  background: linear-gradient(140deg, var(--red), #8e1f1f);
  z-index: 0;
}

.page-about .hero__art::after {
  content: "";
  position: absolute;
  right: 0;
  bottom: 0;
  width: 34%;
  height: 30%;
  border-top: 2px solid var(--gold);
  border-right: 2px solid var(--gold);
  z-index: 2;
}

.page-about .hero__art .frame {
  position: relative;
  z-index: 1;
  border: 1px solid var(--line);
}

/* ---------- 记分牌数据条 ---------- */
.page-about .board {
  list-style: none;
  margin: var(--about-gap) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .board > li {
  background: var(--surface);
  padding: 18px 16px 16px;
  display: grid;
  gap: 8px;
  min-width: 0;
}

.page-about .board .stat__n {
  font-family: var(--font-mono);
  font-size: clamp(26px, 5vw, 38px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--gold);
  font-variant-numeric: tabular-nums;
}

.page-about .board .stat__l {
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--muted);
  line-height: 1.5;
}

/* ---------- 章节头 ---------- */
.page-about .section__head {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 14px;
  padding-bottom: 14px;
  margin-bottom: clamp(20px, 3.4vw, 34px);
  border-bottom: 1px solid var(--line);
}

.page-about .section__num {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.18em;
  color: var(--green);
}

.page-about .section__title {
  margin: 0;
  font-size: clamp(21px, 3.4vw, 34px);
  font-weight: 900;
  line-height: 1.14;
  letter-spacing: -0.01em;
}

.page-about .section + .section {
  padding-top: clamp(24px, 4vw, 48px);
}

/* ---------- 01 起点 ---------- */
.page-about .story__grid {
  align-items: start;
}

.page-about .story__text p {
  margin: 0 0 16px;
}

.page-about .story__text a,
.page-about .partners__text a {
  color: var(--green);
  text-decoration: none;
  border-bottom: 1px solid rgba(124, 255, 138, 0.4);
}

.page-about .story__panel {
  border-left: 3px solid var(--green);
  margin-top: 6px;
}

.page-about .story__panel .panel__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  flex-wrap: wrap;
}

.page-about .story__panel .panel__head .mono {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--muted);
}

.page-about .story__panel .panel__body p {
  margin: 0 0 14px;
  color: var(--muted);
  line-height: 1.75;
  font-size: 15px;
}

.page-about .ticklist {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 9px;
}

.page-about .ticklist li {
  position: relative;
  padding-left: 20px;
  font-size: 14px;
  color: var(--white);
  line-height: 1.6;
}

.page-about .ticklist li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 8px;
  width: 10px;
  height: 2px;
  background: var(--gold);
}

/* ---------- 02 版本时间轴 ---------- */
.page-about .timeline {
  list-style: none;
  margin: 0;
  padding: 0;
  position: relative;
  display: grid;
  gap: 18px;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  top: 10px;
  bottom: 10px;
  left: 25px;
  width: 2px;
  background: linear-gradient(180deg, var(--green), var(--gold) 52%, var(--red));
  opacity: 0.6;
}

.page-about .tl {
  position: relative;
  padding-left: 66px;
}

.page-about .tl__ver {
  position: absolute;
  left: 0;
  top: 0;
  width: 52px;
  height: 52px;
  display: grid;
  place-items: center;
  background: var(--bg);
  border: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--gold);
  font-variant-numeric: tabular-nums;
  z-index: 1;
}

.page-about .tl__body {
  background: var(--surface);
  border: 1px solid var(--line);
  border-left: 3px solid var(--line);
  padding: clamp(16px, 2.8vw, 26px);
}

.page-about .tl:nth-child(1) .tl__body { border-left-color: var(--green); }
.page-about .tl:nth-child(2) .tl__body { border-left-color: var(--gold); }
.page-about .tl:nth-child(3) .tl__body { border-left-color: var(--red); }
.page-about .tl:nth-child(4) .tl__body { border-left-color: var(--paper); }

.page-about .tl__body h3 {
  margin: 12px 0 8px;
  font-size: clamp(16px, 2.2vw, 21px);
  font-weight: 800;
  line-height: 1.3;
}

.page-about .tl__body p {
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--muted);
  max-width: 60ch;
}

/* ---------- 03 团队 ---------- */
.page-about .team__grid {
  align-items: start;
}

.page-about .team__text p {
  margin: 0 0 16px;
}

.page-about .bars {
  display: grid;
  gap: 16px;
  margin-bottom: 22px;
}

.page-about .bar-row {
  display: grid;
  gap: 8px;
}

.page-about .bar-row__top {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 12px;
  font-size: 13px;
  letter-spacing: 0.05em;
  color: var(--muted);
}

.page-about .bar-row__top b {
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--white);
  font-variant-numeric: tabular-nums;
}

.page-about .bar {
  height: 16px;
  background: var(--surface-2);
  border: 1px solid var(--line);
  overflow: hidden;
}

.page-about .bar__fill {
  display: block;
  height: 100%;
  width: var(--fill, 0);
  transition: width 0.8s cubic-bezier(0.22, 0.7, 0.3, 1);
}

.page-about .bar__fill--green { background: linear-gradient(90deg, #3f8f6d, var(--green)); }
.page-about .bar__fill--gold { background: linear-gradient(90deg, #b98a1c, var(--gold)); }
.page-about .bar__fill--line { background: linear-gradient(90deg, #23483b, var(--line)); }

.page-about .team__frame {
  border: 1px solid var(--line);
}

/* ---------- 04 覆盖 ---------- */
.page-about .reach__text p {
  margin: 0 0 16px;
}

.page-about .cover {
  border: 1px solid var(--line);
  background: var(--surface);
  padding: clamp(16px, 3vw, 26px);
}

.page-about .cover__ticks {
  display: grid;
  grid-template-columns: repeat(31, minmax(0, 1fr));
  gap: 2px;
  height: 44px;
  margin-bottom: 16px;
}

.page-about .cover__ticks i {
  display: block;
  background: var(--surface-2);
  border-bottom: 2px solid var(--line);
}

.page-about .cover__ticks i.is-home {
  background: var(--gold);
  border-bottom-color: var(--white);
}

.page-about .cover__bar {
  display: flex;
  height: 32px;
  border: 1px solid var(--line);
}

.page-about .cover__seg {
  display: flex;
  align-items: center;
  padding: 0 10px;
  font-size: 12px;
  letter-spacing: 0.06em;
  white-space: nowrap;
  overflow: hidden;
}

.page-about .cover__seg--home {
  flex: 0 0 30%;
  background: var(--gold);
  color: var(--ink);
  font-weight: 700;
}

.page-about .cover__seg--rest {
  flex: 1 1 auto;
  background: var(--surface-2);
  color: var(--muted);
}

.page-about .cover__legend {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 18px;
  margin: 14px 0 0;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.page-about .cover__legend .mono {
  font-family: var(--font-mono);
  color: var(--gold);
}

.page-about .dot {
  display: inline-block;
  width: 10px;
  height: 10px;
  margin-right: 6px;
  vertical-align: -1px;
}

.page-about .dot--gold { background: var(--gold); }
.page-about .dot--line { background: var(--line); }

/* ---------- 05 合作 ---------- */
.page-about .partners__text p {
  margin: 0 0 16px;
}

.page-about .usecase {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .usecase li {
  display: flex;
  gap: 14px;
  align-items: flex-start;
  background: var(--surface);
  padding: 14px 16px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--muted);
}

.page-about .usecase b {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--green);
  flex: 0 0 auto;
  padding-top: 3px;
}

.page-about .partners__frame {
  border: 1px solid var(--line);
}

/* ---------- 06 三条标准 ---------- */
.page-about .rules__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .rule {
  background: var(--surface);
  padding: clamp(18px, 3vw, 30px);
  display: grid;
  gap: 10px;
  align-content: start;
}

.page-about .rule__no {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--green);
}

.page-about .rule h3 {
  margin: 0;
  font-size: clamp(17px, 2.2vw, 22px);
  font-weight: 800;
  line-height: 1.25;
}

.page-about .rule p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--muted);
}

/* ---------- 结尾 ---------- */
.page-about .cta-wrap {
  padding-bottom: clamp(40px, 7vw, 90px);
}

.page-about .cta {
  position: relative;
  display: grid;
  gap: 24px;
  padding: clamp(24px, 4vw, 48px);
  border: 1px solid var(--line);
  background:
    linear-gradient(122deg, rgba(226, 60, 60, 0.14) 0 30%, transparent 30.2%),
    linear-gradient(180deg, var(--surface-2), var(--surface));
  overflow: hidden;
}

.page-about .cta::after {
  content: "";
  position: absolute;
  right: -40px;
  bottom: -40px;
  width: 180px;
  height: 180px;
  border: 2px solid rgba(255, 201, 74, 0.25);
  border-radius: 50%;
  pointer-events: none;
}

.page-about .cta__text h2 {
  margin: 14px 0 10px;
  font-size: clamp(21px, 3.2vw, 32px);
  font-weight: 900;
  line-height: 1.15;
}

.page-about .cta__text p {
  margin: 0;
  max-width: 52ch;
  font-size: 15px;
  line-height: 1.78;
  color: var(--muted);
}

.page-about .cta__actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  position: relative;
  z-index: 1;
}

.page-about .cta__mail {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--green);
  text-decoration: none;
  border-bottom: 1px dashed rgba(124, 255, 138, 0.5);
  padding-bottom: 2px;
}

/* ---------- 断点 ---------- */
@media (min-width: 720px) {
  .page-about .board {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

  .page-about .cover__ticks {
    height: 56px;
  }
}

@media (min-width: 900px) {
  .page-about .hero__grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
  }

  .page-about .team__grid,
  .page-about .reach__grid,
  .page-about .partners__grid {
    align-items: start;
  }

  .page-about .cta {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: center;
  }

  .page-about .cta__actions {
    justify-content: flex-end;
  }

  .page-about .tl {
    padding-left: 84px;
  }

  .page-about .tl__ver {
    width: 64px;
    height: 64px;
    font-size: 18px;
  }

  .page-about .timeline::before {
    left: 31px;
  }
}

@media (min-width: 1100px) {
  .page-about .tl__body {
    display: grid;
    grid-template-columns: minmax(0, 1fr);
  }

  .page-about .cover__ticks {
    height: 64px;
  }
}

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

.page-about {
  --fill: currentColor;
}