.page-about {
  background:
    radial-gradient(120% 62% at 88% -12%, rgba(75, 227, 200, .10), transparent 58%),
    var(--ink-900);
  color: var(--paper);
  overflow-x: hidden;
}

.page-about h1,
.page-about h2,
.page-about h3 {
  font-family: var(--font-display);
  letter-spacing: -0.02em;
}

.page-about h2 {
  font-size: clamp(26px, 4.4vw, 44px);
  line-height: 1.06;
  font-weight: 800;
  margin: 10px 0 0;
}

.page-about h3 {
  font-size: 18px;
  line-height: 1.3;
  font-weight: 700;
  margin: 0;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding: clamp(22px, 4vw, 40px) 0 clamp(40px, 7vw, 78px);
}

.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 5vw, 44px);
  align-items: start;
  margin-top: clamp(18px, 3vw, 32px);
}

.page-about .about-hero__lead h1 {
  font-size: clamp(32px, 6.6vw, 64px);
  line-height: 1.02;
  font-weight: 800;
  margin: 16px 0 0;
  max-width: 17em;
}

.page-about .about-hero__sub {
  margin: 22px 0 0;
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.85;
  color: var(--paper-2);
  max-width: 50ch;
}

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

.page-about .about-board {
  border: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(28, 48, 38, .92), rgba(6, 11, 9, .55));
  padding: 20px 18px 16px;
}

.page-about .about-board__title {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--cyan);
}

.page-about .about-board__list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-board__row {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 16px;
  align-items: baseline;
  padding: 15px 0;
  border-top: 1px solid var(--line-soft);
}

.page-about .about-board__row:first-child {
  border-top: 0;
}

.page-about .about-board__num {
  font-family: var(--font-mono);
  font-size: clamp(22px, 3vw, 28px);
  line-height: 1;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}

.page-about .about-board__label {
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--muted);
}

/* ---------- 区块骨架 ---------- */
.page-about .about-band {
  padding: clamp(46px, 7vw, 88px) 0;
  border-top: 1px solid var(--line-soft);
}

.page-about .about-band--ink {
  background: linear-gradient(180deg, rgba(6, 11, 9, .62), rgba(6, 11, 9, 0));
}

.page-about .about-band--cta {
  padding-bottom: clamp(56px, 8vw, 104px);
}

.page-about .split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(18px, 3vw, 30px);
  margin-bottom: clamp(26px, 4vw, 46px);
}

.page-about .split__rail {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.page-about .margin-note {
  margin: 0;
  padding-left: 14px;
  border-left: 1px solid var(--line);
  font-size: 13.5px;
  line-height: 1.7;
  letter-spacing: .04em;
  color: var(--muted);
}

.page-about .lede {
  margin: 16px 0 0;
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.8;
  color: var(--paper-2);
  max-width: 52ch;
}

.page-about .body-copy {
  margin-top: 20px;
  max-width: 64ch;
}

.page-about .body-copy p {
  margin: 0 0 1.05em;
  font-size: 16px;
  line-height: 1.85;
  color: var(--paper-2);
}

/* ---------- 四步链路 ---------- */
.page-about .flow {
  list-style: none;
  margin: 0 0 clamp(30px, 5vw, 54px);
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
}

.page-about .flow__step {
  position: relative;
  padding: 18px 18px 22px;
  background: rgba(28, 48, 38, .74);
  border-top: 2px solid var(--cyan);
}

.page-about .flow__step::after {
  content: "";
  position: absolute;
  inset: 0;
  border: 1px solid var(--line-soft);
  border-top: 0;
  pointer-events: none;
}

.page-about .flow__idx {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--cyan);
}

.page-about .flow__step h3 {
  margin: 10px 0 8px;
  font-size: 19px;
}

.page-about .flow__step p {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--paper-2);
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: clamp(24px, 4vw, 44px) 0 0;
}

.page-about .about-figure--flush {
  margin-bottom: clamp(22px, 3.5vw, 36px);
}

.page-about .img-frame {
  position: relative;
  overflow: hidden;
  background: var(--ink-800);
  border: 1px solid var(--line-soft);
}

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

.page-about .figure__cap {
  margin: 12px 0 0;
  font-size: 13px;
  line-height: 1.7;
  letter-spacing: .04em;
  color: var(--muted);
}

/* ---------- 赛区 ---------- */
.page-about .zones {
  list-style: none;
  margin: clamp(24px, 4vw, 40px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
}

.page-about .zone {
  padding: 18px 16px 20px;
  background: rgba(28, 48, 38, .5);
  border-left: 2px solid var(--cyan-deep);
  transition: background .22s var(--ease), border-color .22s var(--ease), transform .22s var(--ease);
}

.page-about .zone:hover {
  background: rgba(28, 48, 38, .95);
  border-left-color: var(--cyan);
  transform: translateX(4px);
}

.page-about .zone__head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
}

.page-about .zone__idx {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .12em;
  color: var(--cyan);
}

.page-about .zone h3 {
  font-size: 16px;
  text-align: right;
}

.page-about .zone p {
  margin: 12px 0 0;
  font-size: 13.5px;
  line-height: 1.75;
  color: var(--muted);
}

/* ---------- 版本时间线 ---------- */
.page-about .timeline {
  position: relative;
  margin-top: clamp(24px, 4vw, 40px);
  padding-left: 22px;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 12px;
  bottom: 12px;
  width: 1px;
  background: linear-gradient(180deg, var(--cyan), rgba(23, 160, 140, .5) 68%, transparent);
}

.page-about .tl-item {
  position: relative;
}

.page-about .tl-item::before {
  content: "";
  position: absolute;
  left: -22px;
  top: 22px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 0 3px rgba(75, 227, 200, .14);
}

.page-about .tl-item:last-child::before {
  animation: about-pulse 2.4s var(--ease) infinite;
}

.page-about .tl-btn {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: 14px;
  width: 100%;
  text-align: left;
  padding: 15px 16px;
  background: rgba(6, 11, 9, .38);
  border: 1px solid var(--line-soft);
  color: var(--paper);
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: border-color .2s var(--ease), background .2s var(--ease);
}

.page-about .tl-btn:hover,
.page-about .tl-btn:focus-visible {
  border-color: var(--cyan);
  background: rgba(6, 11, 9, .62);
}

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

.page-about .tl-title {
  letter-spacing: -0.01em;
}

.page-about .tl-panel .disclosure__inner {
  padding: 14px 16px 18px;
}

.page-about .tl-inner p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.82;
  color: var(--paper-2);
  max-width: 62ch;
}

/* ---------- 合作 ---------- */
.page-about .partners {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin-top: clamp(24px, 4vw, 40px);
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
}

.page-about .partner {
  padding: clamp(20px, 3vw, 32px);
  background: var(--ink-900);
}

.page-about .partner__num {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: clamp(24px, 3.2vw, 32px);
  line-height: 1;
  color: var(--lime);
  font-variant-numeric: tabular-nums;
}

.page-about .partner h3 {
  font-size: 18px;
  margin-bottom: 10px;
}

.page-about .partner p {
  margin: 0;
  font-size: 14px;
  line-height: 1.82;
  color: var(--paper-2);
}

/* ---------- 收尾 ---------- */
.page-about .cta-panel {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 3vw, 34px);
  padding: clamp(24px, 4vw, 46px);
  border: 1px solid var(--line);
  background: linear-gradient(118deg, rgba(28, 48, 38, .95), rgba(6, 11, 9, .86));
}

.page-about .cta-panel__text p {
  margin: 16px 0 0;
  font-size: 15px;
  line-height: 1.82;
  color: var(--paper-2);
  max-width: 46ch;
}

.page-about .cta-panel__links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-content: start;
}

@keyframes about-pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: .42; }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .tl-item:last-child::before {
    animation: none;
  }
  .page-about .zone {
    transition: none;
  }
}

@media (min-width: 640px) {
  .page-about .zones {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .partners {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: clamp(36px, 6vw, 90px);
  }
  .page-about .split {
    grid-template-columns: minmax(0, 3fr) minmax(0, 8fr);
    gap: clamp(32px, 5vw, 74px);
  }
  .page-about .flow {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 0;
  }
  .page-about .flow__step:nth-child(2) {
    margin-top: 26px;
  }
  .page-about .flow__step:nth-child(3) {
    margin-top: 52px;
  }
  .page-about .flow__step:nth-child(4) {
    margin-top: 78px;
  }
  .page-about .cta-panel {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: center;
  }
}

@media (min-width: 1000px) {
  .page-about .zones {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .page-about .partners {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}