:root {
  --bg: #000;
  --fg: #f3f3f3;
  --muted: rgba(243, 243, 243, 0.62);
  --dim: rgba(243, 243, 243, 0.38);
  --line: rgba(255, 255, 255, 0.14);
  --line-strong: rgba(255, 255, 255, 0.28);
  --font: "Inter Tight", "Helvetica Neue", Helvetica, Arial, sans-serif;
  --nav-h: 72px;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  background: var(--bg);
}

html[lang="zh-Hans"] body {
  font-feature-settings: "kern" 1;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--font);
  font-weight: 400;
  font-size: 17px;
  line-height: 1.55;
  letter-spacing: -0.01em;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img,
svg {
  display: block;
  max-width: 100%;
}

a {
  color: inherit;
  text-decoration: none;
}

button {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
  padding: 0;
  cursor: pointer;
}

.progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 1px;
  width: 0;
  background: #fff;
  z-index: 80;
  pointer-events: none;
}

.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 60;
  height: var(--nav-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 36px;
  background: linear-gradient(to bottom, rgba(0, 0, 0, 0.86), rgba(0, 0, 0, 0));
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  letter-spacing: 0.22em;
  font-size: 13px;
  font-weight: 500;
  text-transform: uppercase;
}

.brand svg {
  width: 28px;
  height: 28px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
}

.nav-links a,
.lang button,
.badge {
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--muted);
  transition: color 0.2s ease;
}

.nav-links a:hover,
.lang button:hover,
.lang button.is-active {
  color: var(--fg);
}

.lang {
  display: flex;
  align-items: center;
  gap: 8px;
}

.lang span {
  color: var(--line-strong);
}

.badge {
  border: 1px solid var(--line-strong);
  padding: 6px 10px;
  color: var(--fg);
}

.hero,
.panel {
  position: relative;
  min-height: 100svh;
  padding: calc(var(--nav-h) + 48px) 36px 72px;
  overflow: hidden;
}

.hero {
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
}

.hero-art {
  position: absolute;
  inset: 0;
  pointer-events: none;
}

.grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.04) 1px, transparent 1px);
  background-size: 80px 80px;
  mask-image: radial-gradient(ellipse at 70% 40%, #000 20%, transparent 70%);
}

.glow {
  position: absolute;
  width: 80vw;
  height: 50vh;
  right: -10%;
  top: 10%;
  background: radial-gradient(ellipse, rgba(180, 200, 220, 0.12), transparent 65%);
  filter: blur(8px);
}

.schematic {
  position: absolute;
  right: 4%;
  top: 18%;
  width: min(52vw, 720px);
  opacity: 0.72;
}

.schematic path,
.schematic circle,
.schematic line,
.schematic rect,
.schematic ellipse {
  stroke-dasharray: 1;
  stroke-dashoffset: 1;
  animation: draw 2.8s ease forwards;
}

.schematic .d2 { animation-delay: 0.25s; }
.schematic .d3 { animation-delay: 0.5s; }
.schematic .d4 { animation-delay: 0.75s; }
.schematic .d5 { animation-delay: 1s; }

@keyframes draw {
  to { stroke-dashoffset: 0; }
}

.kicker {
  font-size: 12px;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  color: var(--muted);
  margin: 0 0 22px;
}

.hero h1,
.panel h2 {
  margin: 0;
  font-weight: 500;
  letter-spacing: -0.045em;
  line-height: 0.9;
}

.hero h1 {
  font-size: clamp(3.2rem, 11vw, 8.4rem);
  max-width: 16ch;
}

.lede {
  max-width: 36rem;
  margin: 28px 0 0;
  font-size: clamp(1.05rem, 1.6vw, 1.25rem);
  font-weight: 300;
  color: var(--muted);
  line-height: 1.5;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 40px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 22px;
  border: 1px solid #fff;
  font-size: 11px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  transition: background 0.2s ease, color 0.2s ease;
}

.btn:hover {
  background: #fff;
  color: #000;
}

.btn.ghost {
  border-color: var(--line-strong);
  color: var(--muted);
}

.btn.ghost:hover {
  border-color: #fff;
  color: #000;
  background: #fff;
}

.scroll-cue {
  position: absolute;
  right: 36px;
  bottom: 32px;
  font-size: 10px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--dim);
}

.panel {
  display: flex;
  flex-direction: column;
  justify-content: center;
  border-top: 1px solid var(--line);
}

.panel h2 {
  font-size: clamp(2.4rem, 6.4vw, 5.2rem);
  max-width: 16ch;
}

.panel .copy {
  max-width: 40rem;
  margin-top: 28px;
  color: var(--muted);
  font-weight: 300;
  font-size: 1.15rem;
}

.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: end;
}

.systems {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0;
  margin-top: 64px;
  border-top: 1px solid var(--line);
}

.system {
  padding: 36px 32px 8px 0;
  border-right: 1px solid var(--line);
}

.system:last-child {
  border-right: 0;
  padding-right: 0;
}

.system .idx {
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--dim);
  margin-bottom: 18px;
}

.system h3 {
  margin: 0 0 14px;
  font-size: clamp(1.4rem, 2.4vw, 2rem);
  font-weight: 500;
  letter-spacing: -0.03em;
}

.system p {
  margin: 0;
  color: var(--muted);
  font-weight: 300;
  max-width: 32ch;
}

.specs {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0;
  margin-top: 56px;
  border-top: 1px solid var(--line);
}

.spec {
  padding: 24px 28px 0 0;
  border-right: 1px solid var(--line);
}

.spec:last-child {
  border-right: 0;
  padding-right: 0;
}

.spec dt {
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--dim);
}

.spec dd {
  margin: 10px 0 0;
  font-size: 1.15rem;
  font-weight: 500;
  letter-spacing: -0.02em;
}

.note {
  margin-top: 36px;
  max-width: 44rem;
  color: var(--dim);
  font-size: 0.95rem;
  font-weight: 300;
}

.footer {
  border-top: 1px solid var(--line);
  padding: 48px 36px 36px;
}

.footer-top {
  display: flex;
  justify-content: space-between;
  gap: 40px;
  align-items: flex-start;
}

.footer .brand {
  margin-bottom: 20px;
}

.footer p,
.footer small {
  display: block;
  max-width: 40rem;
  color: var(--dim);
  font-size: 13px;
  font-weight: 300;
  line-height: 1.6;
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: 10px;
  text-align: right;
  font-size: 13px;
  letter-spacing: 0.08em;
}

.footer-links a:hover {
  color: var(--fg);
}

.footer-bottom {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  margin-top: 48px;
  padding-top: 20px;
  border-top: 1px solid var(--line);
  color: var(--dim);
  font-size: 12px;
  letter-spacing: 0.08em;
}

.not-found {
  min-height: 100svh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 120px 36px;
}

.not-found h1 {
  font-size: clamp(3rem, 8vw, 6rem);
  margin: 0 0 16px;
  letter-spacing: -0.04em;
  font-weight: 500;
}

body[data-site="cart"] .hero-default { display: none; }
body[data-site="vision"] .hero-cart { display: none; }
body[data-site="cart"] .hero-cart { display: block; }
body[data-site="vision"] .hero-default { display: block; }

@media (max-width: 900px) {
  .nav { padding: 0 20px; }
  .nav-links a.desktop { display: none; }
  .hero,
  .panel,
  .footer { padding-left: 20px; padding-right: 20px; }
  .schematic {
    width: 90vw;
    right: -18%;
    top: 12%;
    opacity: 0.35;
  }
  .split,
  .systems,
  .specs {
    grid-template-columns: 1fr;
  }
  .system,
  .spec {
    border-right: 0;
    border-bottom: 1px solid var(--line);
    padding: 28px 0;
  }
  .scroll-cue { display: none; }
  .footer-top,
  .footer-bottom {
    flex-direction: column;
  }
  .footer-links { text-align: left; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .schematic path,
  .schematic circle,
  .schematic line,
  .schematic rect,
  .schematic ellipse {
    animation: none;
    stroke-dashoffset: 0;
  }
}