:root {
  --bg-primary: #0a0a0f;
  --bg-secondary: #12121a;
  --bg-card: #1a1a2e;
  --bg-code: #16162a;
  --text-primary: #e8e8f0;
  --text-secondary: #9898b0;
  --text-muted: #606078;
  --accent-t: #4ade80;
  --accent-o: #94a3b8;
  --accent-a: #f87171;
  --accent-u: #6366f1;
  --accent-gold: #fbbf24;
  --accent-blue: #60a5fa;
  --border: #2a2a3e;
  --radius: 12px;
  --radius-sm: 6px;
  --font-mono: 'SF Mono', 'Fira Code', 'JetBrains Mono', monospace;
  --font-sans: -apple-system, 'Pretendard', 'Noto Sans KR', sans-serif;
  --max-width: 1200px;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--accent-blue); text-decoration: none; }
a:hover { text-decoration: underline; }

.container { max-width: var(--max-width); margin: 0 auto; padding: 0 24px; }

code, pre {
  font-family: var(--font-mono);
  font-size: 0.9rem;
}

pre {
  background: var(--bg-code);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  overflow-x: auto;
  line-height: 1.6;
}

.badge {
  display: inline-block;
  padding: 4px 12px;
  border-radius: 20px;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.05em;
}

.badge-t { background: rgba(74,222,128,0.15); color: var(--accent-t); }
.badge-o { background: rgba(148,163,184,0.15); color: var(--accent-o); }
.badge-a { background: rgba(248,113,113,0.15); color: var(--accent-a); }
.badge-u { background: rgba(99,102,241,0.15); color: var(--accent-u); }

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: var(--radius);
  font-size: 1rem;
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: all 0.2s;
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent-t), var(--accent-u));
  color: #fff;
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 8px 24px rgba(99,102,241,0.3); }

.btn-outline {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-primary);
}
.btn-outline:hover { border-color: var(--accent-u); color: var(--accent-u); }

.section { padding: 80px 0; }
.section-title {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 16px;
}
.section-subtitle {
  font-size: 1.1rem;
  color: var(--text-secondary);
  margin-bottom: 48px;
}

.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }

.trit {
  display: inline-flex; align-items: center; justify-content: center;
  width: 28px; height: 28px; border-radius: 4px; font-weight: 700;
  font-family: var(--font-mono); font-size: 0.8rem;
}
.trit-t { background: rgba(74,222,128,0.15); color: var(--accent-t); }
.trit-o { background: rgba(148,163,184,0.1); color: var(--accent-o); }
.trit-a { background: rgba(248,113,113,0.15); color: var(--accent-a); }
.trit-u { background: rgba(99,102,241,0.1); color: var(--accent-u); }

.mobile-toggle {
  display: none; background: none; border: none; color: var(--text-primary);
  font-size: 1.5rem; cursor: pointer; padding: 4px 8px;
}

@media (max-width: 768px) {
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .section { padding: 48px 0; }
  .section-title { font-size: 1.5rem; }
  .mobile-toggle { display: block; }
  .nav-links { display: none; position: absolute; top: 64px; left: 0; right: 0;
    flex-direction: column; background: var(--bg-secondary); border-bottom: 1px solid var(--border);
    padding: 16px 24px; gap: 12px; z-index: 99; }
  .nav-links.open { display: flex; }
  .nav-links a { font-size: 1rem; padding: 8px 0; }
  .lang-select { width: 100%; }
}