:root {
  --bg: #0d1014;
  --bg-alt: #11151a;
  --bg-card: #161b22;
  --bg-card-hover: #1c232c;
  --bg-nav: rgba(13, 16, 20, 0.85);

  --fg: #f0f3f6;
  --fg-sub: #c9d1d9;
  --fg-dim: #8b949e;
  --fg-mute: #6e7681;

  --border: #21262d;
  --border-hover: #30363d;

  --accent: #0078d4;
  --accent-hover: #1a8cff;
  --accent-soft: rgba(0, 120, 212, 0.15);

  --radius: 6px;
  --radius-lg: 10px;

  --max-w: 1180px;

  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html {
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
}

section[id] {
  scroll-margin-top: 80px;
}

body {
  position: relative;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

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

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

.bg-binary {
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  overflow: hidden;
  mask-image: linear-gradient(
    to bottom,
    rgba(0, 0, 0, 1) 0%,
    rgba(0, 0, 0, 0.85) 25%,
    rgba(0, 0, 0, 0.4) 55%,
    rgba(0, 0, 0, 0) 90%
  );
  -webkit-mask-image: linear-gradient(
    to bottom,
    rgba(0, 0, 0, 1) 0%,
    rgba(0, 0, 0, 0.85) 25%,
    rgba(0, 0, 0, 0.4) 55%,
    rgba(0, 0, 0, 0) 90%
  );
}

#binaryCanvas {
  display: block;
  width: 100%;
  height: 100%;
  opacity: 0.55;
}

.bg-binary::after {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(
    ellipse 70% 55% at 50% 40%,
    transparent 0%,
    rgba(13, 16, 20, 0.35) 55%,
    rgba(13, 16, 20, 0.85) 100%
  );
  pointer-events: none;
}

::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb {
  background: #30363d;
  border-radius: 5px;
  border: 2px solid var(--bg);
}
::-webkit-scrollbar-thumb:hover { background: #4a525c; }

* {
  scrollbar-width: thin;
  scrollbar-color: #30363d var(--bg);
}

.container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 32px;
  position: relative;
  z-index: 1;
}

.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--bg-nav);
  backdrop-filter: saturate(180%) blur(16px);
  -webkit-backdrop-filter: saturate(180%) blur(16px);
  border-bottom: 1px solid var(--border);
}

.nav-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 12px 32px;
  display: flex;
  align-items: center;
  gap: 32px;
}

.logo {
  font-size: 17px;
  font-weight: 700;
  letter-spacing: -0.2px;
  color: var(--fg);
  flex-shrink: 0;
}

.nav-links {
  display: flex;
  gap: 28px;
  flex: 1;
}

.nav-links a {
  color: var(--fg-sub);
  font-size: 14px;
  transition: color .15s;
}

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

.nav-right {
  display: flex;
  align-items: center;
  gap: 14px;
  flex-shrink: 0;
}

.lang-switch {
  display: flex;
  gap: 2px;
  padding: 2px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

.lang-switch button {
  background: transparent;
  border: none;
  color: var(--fg-dim);
  padding: 4px 10px;
  font-size: 12px;
  border-radius: 4px;
  cursor: pointer;
  font-family: inherit;
  font-weight: 500;
  transition: all .15s;
}

.lang-switch button:hover { color: var(--fg); }

.lang-switch button.active {
  color: #fff;
  background: var(--accent);
}

.btn {
  display: inline-block;
  padding: 12px 24px;
  border-radius: var(--radius);
  font-size: 15px;
  font-weight: 500;
  border: 1px solid transparent;
  cursor: pointer;
  transition: all .15s;
  font-family: inherit;
  text-align: center;
  line-height: 1.2;
  position: relative;
  z-index: 1;
}

.btn-primary {
  background: var(--accent);
  color: #fff;
}

.btn-primary:hover {
  background: var(--accent-hover);
}

.btn-secondary {
  background: rgba(13, 16, 20, 0.6);
  color: var(--fg);
  border-color: var(--border-hover);
  backdrop-filter: blur(8px);
}

.btn-secondary:hover {
  background: var(--bg-card);
  border-color: var(--fg-mute);
}

.hero {
  padding: 96px 0 80px;
  text-align: center;
  position: relative;
  z-index: 1;
}

.hero h1 {
  font-size: 56px;
  font-weight: 700;
  letter-spacing: -1.5px;
  line-height: 1.1;
  margin-bottom: 24px;
  color: var(--fg);
  max-width: 820px;
  margin-left: auto;
  margin-right: auto;
  text-shadow: 0 2px 24px rgba(13, 16, 20, 0.9);
}

.hero-sub {
  font-size: 18px;
  color: var(--fg-sub);
  max-width: 680px;
  margin: 0 auto 40px;
  line-height: 1.6;
  text-shadow: 0 1px 12px rgba(13, 16, 20, 0.9);
}

.hero-actions {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 64px;
}

.hero-image {
  max-width: 1000px;
  margin: 0 auto;
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--border);
  background: var(--bg-card);
  box-shadow: 0 24px 64px rgba(0, 0, 0, 0.6);
}

.hero-image img {
  width: 100%;
  height: auto;
}

.section {
  padding: 96px 0;
  border-top: 1px solid var(--border);
  position: relative;
  z-index: 1;
  background: var(--bg);
}

.section-alt {
  background: var(--bg-alt);
}

.section-title {
  font-size: 40px;
  font-weight: 700;
  letter-spacing: -0.8px;
  line-height: 1.2;
  margin-bottom: 16px;
  color: var(--fg);
  text-align: center;
}

.section-sub {
  font-size: 17px;
  color: var(--fg-sub);
  max-width: 640px;
  margin: 0 auto 56px;
  text-align: center;
  line-height: 1.6;
}

.features {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.feature {
  padding: 28px 24px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  transition: border-color .15s, background .15s;
}

.feature:hover {
  border-color: var(--border-hover);
  background: var(--bg-card-hover);
}

.feature h3 {
  font-size: 16px;
  font-weight: 600;
  color: var(--fg);
  margin-bottom: 10px;
}

.feature p {
  font-size: 14px;
  color: var(--fg-dim);
  line-height: 1.55;
}

.download-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-bottom: 40px;
}

.download-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 36px 24px 28px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  text-align: center;
  transition: all .2s;
}

.download-card:hover {
  border-color: var(--accent);
  background: var(--bg-card-hover);
  transform: translateY(-2px);
}

.os-name {
  font-size: 22px;
  font-weight: 600;
  color: var(--fg);
  margin-bottom: 6px;
  letter-spacing: -0.2px;
}

.os-note {
  font-size: 13px;
  color: var(--fg-dim);
}

.os-desc {
  font-size: 12px;
  color: var(--fg-mute);
  margin-top: 20px;
  padding-top: 16px;
  border-top: 1px solid var(--border);
  width: 100%;
  margin-bottom: 20px;
}

.download-btn {
  width: 100%;
  margin-top: auto;
  font-size: 14px;
  padding: 10px 20px;
}

.download-foot {
  font-size: 14px;
  color: var(--fg-dim);
  max-width: 720px;
  margin: 0 auto 32px;
  text-align: center;
  line-height: 1.65;
}

.download-help {
  max-width: 720px;
  margin: 0 auto;
  padding: 20px 24px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  text-align: center;
}

.download-help p {
  font-size: 14px;
  color: var(--fg-sub);
  line-height: 1.6;
  margin-bottom: 12px;
}

.download-help-link {
  display: inline-block;
  font-size: 14px;
  font-weight: 500;
  color: var(--accent-hover);
  transition: color .15s;
  border-bottom: 1px solid transparent;
  padding-bottom: 1px;
}

.download-help-link:hover {
  color: #6fb8ff;
  border-bottom-color: #6fb8ff;
}

.download-help-link::after {
  content: " \2192";
  font-size: 13px;
}

.footer {
  padding: 56px 0 32px;
  border-top: 1px solid var(--border);
  background: var(--bg-alt);
  position: relative;
  z-index: 1;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 24px;
  margin-bottom: 32px;
}

.footer-logo {
  font-size: 16px;
  font-weight: 700;
  color: var(--fg);
}

.footer-tag {
  font-size: 13px;
  color: var(--fg-dim);
  margin-top: 4px;
}

.social-links {
  display: flex;
  gap: 12px;
  align-items: center;
}

.social-links a {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius);
  background: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--fg-sub);
  transition: all .2s;
}

.social-links a:hover {
  color: var(--fg);
  background: var(--bg-card-hover);
  border-color: var(--accent);
  transform: translateY(-2px);
}

.social-links a svg {
  display: block;
}

.footer-copy {
  font-size: 12px;
  color: var(--fg-mute);
  text-align: center;
  padding-top: 24px;
  border-top: 1px solid var(--border);
}

@media (max-width: 900px) {
  .features,
  .download-grid {
    grid-template-columns: 1fr;
  }

  .hero h1 { font-size: 40px; }
  .section-title { font-size: 30px; }
  .section { padding: 64px 0; }
  .hero { padding: 64px 0 56px; }
}

@media (max-width: 720px) {
  html { scroll-padding-top: 130px; }
  section[id] { scroll-margin-top: 130px; }

  .container { padding: 0 20px; }

  .nav-inner {
    padding: 10px 20px;
    gap: 16px;
    flex-wrap: wrap;
  }

  .nav-links {
    order: 3;
    width: 100%;
    justify-content: flex-start;
    gap: 20px;
  }

  .hero h1 { font-size: 34px; letter-spacing: -1px; }
  .hero-sub { font-size: 16px; }
  .section-title { font-size: 26px; }
  .section-sub { font-size: 15px; }

  .hero-actions { flex-direction: column; }
  .hero-actions .btn { width: 100%; }

  .footer-inner { flex-direction: column; text-align: center; }
  .social-links { justify-content: center; }
}

@media (prefers-reduced-motion: reduce) {
  #binaryCanvas { opacity: 0.3; }
  .download-card,
  .social-links a { transition: none; }
}

.nav-links a.active { color: var(--fg); }