:root {
  --bt-bg-0: #0a0e1a;
  --bt-bg-1: #111827;
  --bt-card: #1a2235;
  --bt-border: #1e293b;

  --bt-text: #ffffff;
  --bt-text-muted: #94a3b8;
  --bt-text-muted-2: #64748b;

  --bt-accent-green: #00ff88;
  --bt-accent-cyan: #00d9ff;
  --bt-accent-yellow: #ffd600;

  --bt-radius: 14px;
}

html {
  color-scheme: dark;
}

body {
  margin: 0;
  background: linear-gradient(to bottom, var(--bt-bg-1), var(--bt-bg-0));
  color: var(--bt-text);
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, "Apple Color Emoji", "Segoe UI Emoji";
}

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

a:hover {
  color: var(--bt-text);
}

.bt-container {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 24px;
}

.bt-section {
  padding: 96px 0;
}

.bt-card {
  border: 1px solid var(--bt-border);
  border-radius: var(--bt-radius);
  background: color-mix(in srgb, var(--bt-card) 70%, transparent);
  backdrop-filter: blur(8px);
}

.bt-muted {
  color: var(--bt-text-muted);
}

.bt-h2 {
  font-size: clamp(28px, 3vw, 40px);
  font-weight: 600;
  line-height: 1.1;
  margin: 0 0 16px 0;
}

.bt-h3 {
  font-size: 18px;
  font-weight: 600;
  margin: 0 0 12px 0;
}

.bt-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  border-radius: 999px;
  border: 1px solid color-mix(in srgb, var(--bt-accent-cyan) 30%, transparent);
  background: color-mix(in srgb, var(--bt-accent-cyan) 10%, transparent);
  padding: 6px 14px;
  color: var(--bt-accent-cyan);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  font-size: 12px;
}

.bt-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 12px;
  padding: 12px 16px;
  font-weight: 600;
  border: 1px solid var(--bt-border);
  background: color-mix(in srgb, var(--bt-card) 70%, transparent);
  color: var(--bt-text);
}

.bt-btn:hover {
  border-color: color-mix(in srgb, var(--bt-accent-cyan) 40%, var(--bt-border));
  background: color-mix(in srgb, var(--bt-card) 85%, transparent);
}

.bt-btn-primary {
  border: 0;
  background: linear-gradient(90deg, var(--bt-accent-green), var(--bt-accent-cyan));
  color: #ffffff;
}

.bt-btn-primary:hover {
  filter: brightness(1.05);
}

.bt-nav {
  position: sticky;
  top: 0;
  z-index: 50;
  border-bottom: 1px solid var(--bt-border);
  background: color-mix(in srgb, var(--bt-bg-1) 85%, transparent);
  backdrop-filter: blur(10px);
}

.bt-nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 16px 0;
}

.bt-brand {
  font-weight: 700;
  letter-spacing: 0.02em;
}

.bt-menu {
  display: flex;
  align-items: center;
  gap: 18px;
  color: var(--bt-text-muted);
}

.bt-menu a:hover {
  color: var(--bt-text);
}

.bt-nav-right {
  display: flex;
  align-items: center;
  gap: 12px;
}

.bt-lang {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  border-radius: 12px;
  border: 1px solid var(--bt-border);
  background: color-mix(in srgb, var(--bt-card) 70%, transparent);
  padding: 8px 10px;
  color: var(--bt-text-muted);
}

.bt-lang a {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--bt-text-muted);
}

.bt-lang a:hover {
  color: var(--bt-text);
}

.bt-lang .is-active {
  color: var(--bt-accent-cyan);
}

.bt-footer {
  border-top: 1px solid var(--bt-border);
  background: color-mix(in srgb, var(--bt-bg-0) 70%, transparent);
  padding: 48px 0;
}

.bt-footer-grid {
  display: grid;
  grid-template-columns: repeat(1, minmax(0, 1fr));
  gap: 24px;
}

@media (min-width: 900px) {
  .bt-footer-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

.bt-footer h4 {
  margin: 0 0 10px 0;
  font-size: 14px;
  font-weight: 700;
  color: var(--bt-text);
}

.bt-footer a {
  color: var(--bt-text-muted);
}

.bt-footer a:hover {
  color: var(--bt-text);
}

.bt-hero {
  position: relative;
  overflow: hidden;
}

.bt-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 50% 40%, color-mix(in srgb, var(--bt-accent-green) 12%, transparent), transparent 55%);
  filter: blur(20px);
  opacity: 0.9;
  pointer-events: none;
}

.bt-hero-inner {
  position: relative;
  padding: 96px 0;
  text-align: center;
}

.bt-hero-title {
  font-size: clamp(34px, 5vw, 58px);
  font-weight: 700;
  line-height: 1.05;
  margin: 14px 0 14px 0;
}

.bt-gradient-text {
  background: linear-gradient(90deg, var(--bt-accent-green), var(--bt-accent-cyan), var(--bt-accent-yellow));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.bt-hero-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 12px;
  margin-top: 22px;
}