.page-about {
  position: relative;
  isolation: isolate;
  color: var(--text);
  font-family: var(--font-sans);
  padding-bottom: clamp(56px, 8vw, 100px);
  background:
    radial-gradient(110% 60% at 88% -8%, rgba(64, 58, 143, 0.22), transparent 62%),
    radial-gradient(90% 55% at 0% 102%, rgba(124, 47, 75, 0.16), transparent 66%),
    var(--ink);
}

.page-about::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-image:
    linear-gradient(to right, rgba(30, 70, 87, 0.4) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(30, 70, 87, 0.4) 1px, transparent 1px);
  background-size: 88px 88px;
  -webkit-mask-image: linear-gradient(to bottom, #000 0, #000 52%, transparent 100%);
  mask-image: linear-gradient(to bottom, #000 0, #000 52%, transparent 100%);
}

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

.page-about p {
  margin: 0;
  color: var(--muted);
  font-size: clamp(14px, 1.5vw, 16px);
  line-height: 1.78;
}

.page-about h1,
.page-about h2,
.page-about h3 {
  margin: 0;
  color: var(--text);
  letter-spacing: 0.02em;
  line-height: 1.14;
}

.page-about h2 {
  font-size: clamp(23px, 3.2vw, 32px);
  font-weight: 800;
}

.page-about h3 {
  font-size: clamp(17px, 2vw, 20px);
  font-weight: 700;
}

.page-about .kicker {
  color: var(--mint-deep);
}

.page-about .breadcrumb {
  padding-top: clamp(14px, 2.4vw, 22px);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  display: grid;
  gap: 26px;
  padding-block: clamp(20px, 3.4vw, 34px) clamp(32px, 5vw, 56px);
}

.page-about .about-hero__lead {
  margin-top: 18px;
  max-width: 33em;
  color: var(--text);
  font-size: clamp(15px, 1.7vw, 17px);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 24px;
}

.page-about .about-hero__panel {
  border: 1px solid var(--line);
  border-left: 2px solid var(--mint);
  border-radius: var(--radius);
  background: var(--glass);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  padding: 16px;
}

.page-about .hstats {
  list-style: none;
  margin: 14px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  background: var(--line);
}

.page-about .hstats__item {
  display: flex;
  flex-direction: column;
  gap: 5px;
  padding: 12px 10px;
  background: rgba(14, 34, 51, 0.92);
}

.page-about .hstats__num {
  font-family: var(--font-mono);
  font-size: clamp(22px, 3vw, 27px);
  font-weight: 700;
  line-height: 1;
  color: var(--mint);
}

.page-about .hstats__label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--muted);
}

/* ---------- 通用分段 ---------- */
.page-about .about-origin,
.page-about .about-tl,
.page-about .about-flow,
.page-about .about-team,
.page-about .about-versions,
.page-about .about-partners,
.page-about .about-rules {
  padding-block: clamp(36px, 5vw, 64px);
  border-top: 1px solid var(--line);
}

.page-about .about-head {
  display: grid;
  gap: 10px;
  max-width: 56ch;
  margin-bottom: clamp(22px, 3.2vw, 36px);
}

/* ---------- 起点 ---------- */
.page-about .about-origin__grid {
  display: grid;
  gap: 26px;
}

.page-about .about-origin__text {
  display: grid;
  gap: 14px;
  margin-top: 16px;
}

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

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  background: var(--panel-2);
  filter: saturate(0.85) contrast(1.06) brightness(0.92);
  clip-path: polygon(0 4%, 100% 0, 100% 96%, 0 100%);
}

.page-about .about-figure figcaption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--muted);
}

/* ---------- 时间轴 ---------- */
.page-about .tl {
  list-style: none;
  margin: 0;
  padding: 0;
  position: relative;
}

.page-about .tl::before {
  content: "";
  position: absolute;
  left: 9px;
  top: 10px;
  bottom: 10px;
  width: 1px;
  background: linear-gradient(to bottom, var(--line) 0%, var(--mint-deep) 46%, var(--line) 100%);
}

.page-about .tl__item {
  position: relative;
  display: grid;
  gap: 10px;
  padding-left: 34px;
  padding-bottom: 26px;
}

.page-about .tl__item:last-child {
  padding-bottom: 0;
}

.page-about .tl__item::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 9px;
  width: 11px;
  height: 11px;
  border: 1px solid var(--mint-deep);
  background: var(--ink);
  transform: rotate(45deg);
  transition: background 0.16s var(--ease), border-color 0.16s var(--ease);
}

.page-about .tl__item:hover::before,
.page-about .tl__item:focus-within::before {
  background: var(--mint);
  border-color: var(--mint);
}

.page-about .tl__year {
  display: flex;
  align-items: center;
  gap: 10px;
}

.page-about .tl__year .num {
  font-family: var(--font-mono);
  font-size: clamp(26px, 3.6vw, 34px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--text);
  transition: color 0.16s var(--ease);
}

.page-about .tl__item:hover .tl__year .num {
  color: var(--mint);
}

.page-about .tl__body {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 16px;
  transition: transform 0.16s var(--ease), border-color 0.16s var(--ease);
}

.page-about .tl__item:hover .tl__body {
  transform: translateY(-2px);
  border-color: var(--mint-deep);
}

.page-about .tl__body h3 {
  margin-bottom: 8px;
}

.page-about .tl__body p + p {
  margin-top: 8px;
}

.page-about .tl__kw {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--mint-deep);
}

/* ---------- 流程 ---------- */
.page-about .flow {
  display: grid;
  gap: 12px;
}

.page-about .flow__step {
  position: relative;
  padding: 18px 16px;
  border: 1px solid var(--line);
  border-top: 2px solid var(--mint-deep);
  border-radius: var(--radius);
  background: var(--panel);
}

.page-about .flow__idx {
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--mint);
}

.page-about .flow__step h3 {
  margin-bottom: 8px;
}

.page-about .flow__rhythm {
  display: grid;
  gap: 1px;
  margin-top: 16px;
  border: 1px solid var(--line);
  background: var(--line);
}

.page-about .flow__beat {
  padding: 16px;
  background: var(--panel-2);
}

.page-about .flow__beat b {
  display: block;
  margin-bottom: 6px;
  font-family: var(--font-mono);
  font-size: clamp(18px, 2.4vw, 22px);
  letter-spacing: 0.04em;
  color: var(--amber);
}

/* ---------- 团队 ---------- */
.page-about .about-team__wrap {
  display: grid;
  gap: 24px;
}

.page-about .team__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.page-about .team__card {
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--glass);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
  transition: transform 0.16s var(--ease), border-color 0.16s var(--ease), background 0.16s var(--ease);
}

.page-about .team__card:hover,
.page-about .team__card:focus {
  transform: translateY(-2px);
  border-color: var(--mint-deep);
  background: var(--glass-strong);
}

.page-about .team__card:focus-visible {
  outline: 2px solid var(--mint);
  outline-offset: 2px;
}

.page-about .team__num {
  font-family: var(--font-mono);
  font-size: clamp(24px, 3.4vw, 30px);
  font-weight: 700;
  line-height: 1;
  color: var(--mint);
}

.page-about .team__label {
  margin-top: 6px;
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--text);
}

.page-about .team__more {
  margin-top: 8px;
  font-size: 12px;
  line-height: 1.6;
  color: var(--muted);
  opacity: 0.55;
  transition: opacity 0.16s var(--ease);
}

.page-about .team__card:hover .team__more,
.page-about .team__card:focus .team__more {
  opacity: 1;
}

.page-about .about-figure--team img {
  aspect-ratio: 10 / 7;
}

/* ---------- 版本轨道 ---------- */
.page-about .about-figure--wide {
  margin-bottom: 20px;
}

.page-about .about-figure--wide img {
  aspect-ratio: 14 / 5;
  clip-path: polygon(0 0, 100% 8%, 100% 100%, 0 92%);
}

.page-about .vrail {
  display: flex;
  gap: 14px;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  padding: 4px 4px 16px;
  scrollbar-width: thin;
  scrollbar-color: var(--mint-deep) transparent;
}

.page-about .vrail::-webkit-scrollbar {
  height: 6px;
}

.page-about .vrail::-webkit-scrollbar-track {
  background: rgba(30, 70, 87, 0.4);
}

.page-about .vrail::-webkit-scrollbar-thumb {
  background: var(--mint-deep);
  border-radius: 99px;
}

.page-about .vrail:focus-visible {
  outline: 2px solid var(--mint);
  outline-offset: 4px;
}

.page-about .vrail__card {
  flex: 0 0 min(78%, 300px);
  scroll-snap-align: start;
  display: flex;
  flex-direction: column;
  gap: 8px;
  min-height: 176px;
  padding: 16px;
  border: 1px solid var(--line);
  border-top: 2px solid var(--indigo);
  border-radius: var(--radius);
  background: var(--panel);
  transition: transform 0.16s var(--ease), border-color 0.16s var(--ease);
}

.page-about .vrail__card:hover {
  transform: translateY(-2px);
  border-color: var(--mint-deep);
}

.page-about .vrail__card h3 {
  font-size: 17px;
}

.page-about .vrail__meta {
  margin-top: auto;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--muted);
}

/* ---------- 合作 ---------- */
.page-about .partners {
  display: grid;
  gap: 1px;
  border: 1px solid var(--line);
  background: var(--line);
}

.page-about .partners__cell {
  padding: 18px 16px;
  background: var(--panel-2);
}

.page-about .partners__num {
  font-family: var(--font-mono);
  font-size: clamp(26px, 3.6vw, 34px);
  font-weight: 700;
  line-height: 1;
  color: var(--mint);
}

.page-about .partners__title {
  margin-top: 8px;
  margin-bottom: 8px;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--text);
}

/* ---------- 准则 ---------- */
.page-about .rules {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.page-about .rules__item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 14px;
  padding: 16px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .rules__idx {
  padding-top: 3px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--mint);
}

.page-about .rules__item strong {
  color: var(--text);
  font-weight: 700;
}

/* ---------- 收尾 ---------- */
.page-about .about-cta {
  display: grid;
  gap: 18px;
  margin-top: clamp(36px, 5vw, 64px);
  padding: clamp(20px, 3.2vw, 34px);
  border: 1px solid var(--line);
  border-left: 3px solid var(--mint);
  border-radius: var(--radius);
  background: var(--panel);
}

.page-about .about-cta p {
  margin-top: 8px;
  max-width: 46ch;
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

/* ---------- 断点 ---------- */
@media (min-width: 640px) {
  .page-about .flow__rhythm {
    grid-template-columns: 1fr 1fr;
  }

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

@media (min-width: 760px) {
  .page-about .flow {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 14px;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero {
    grid-template-columns: minmax(0, 1.5fr) minmax(280px, 0.85fr);
    gap: clamp(40px, 5vw, 64px);
    align-items: end;
    padding-block: clamp(24px, 3vw, 40px) clamp(40px, 5vw, 64px);
  }

  .page-about .about-origin__grid {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    gap: clamp(28px, 4vw, 56px);
    align-items: center;
  }

  .page-about .tl::before {
    left: 116px;
  }

  .page-about .tl__item {
    grid-template-columns: 96px minmax(0, 1fr);
    gap: 40px;
    padding-left: 0;
    padding-bottom: 30px;
  }

  .page-about .tl__item::before {
    left: 110px;
    top: 14px;
  }

  .page-about .tl__year {
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
    padding-top: 4px;
  }

  .page-about .about-team__wrap {
    grid-template-columns: minmax(0, 1fr) minmax(0, 0.82fr);
    gap: clamp(28px, 4vw, 48px);
    align-items: center;
  }

  .page-about .team__grid {
    grid-template-columns: 1fr 1fr;
    gap: 14px;
  }

  .page-about .rules {
    display: grid;
    grid-template-columns: 1fr 1fr;
    column-gap: clamp(28px, 4vw, 56px);
  }

  .page-about .about-cta {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    gap: 28px;
  }
}

@media (min-width: 1100px) {
  .page-about .vrail__card {
    flex-basis: 320px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .tl__item::before,
  .page-about .tl__year .num,
  .page-about .tl__body,
  .page-about .team__card,
  .page-about .team__more,
  .page-about .vrail__card {
    transition: none;
  }

  .page-about .tl__item:hover .tl__body,
  .page-about .team__card:hover,
  .page-about .team__card:focus,
  .page-about .vrail__card:hover {
    transform: none;
  }
}