/* ============================================
   DESIGN TOKENS & RESET
   ============================================ */
:root {
  /* Spacing */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;
  --space-4xl: 6rem;
  --space-section: clamp(3.5rem, 8vh, 5rem);

  /* Colors (Dark - default) */
  --bg: #09090b;
  --bg-surface: #18181b;
  --bg-elevated: #27272a;
  --border: #27272a;
  --border-hover: #3f3f46;
  --text-primary: #fafafa;
  --text-secondary: #a1a1aa;
  --text-muted: #8b8b93;
  --accent: #d4d4d8;
  --accent-hover: #fafafa;
  --accent-dim: rgba(212, 212, 216, 0.08);

  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.25);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.3);

  /* Radius */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;

  /* Transitions */
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --ease-in-out: cubic-bezier(0.4, 0, 0.2, 1);
  --duration-fast: 150ms;
  --duration-normal: 300ms;
  --duration-slow: 500ms;

  /* Typography */
  --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

  /* Container */
  --container-max: 1100px;
  --container-padding: clamp(1.25rem, 4vw, 3rem);

  /* Marquee */
  --marquee-speed: 30s;
}

/* Light mode */
body.light {
  --bg: #fafafa;
  --bg-surface: #ffffff;
  --bg-elevated: #f4f4f5;
  --border: #e4e4e7;
  --border-hover: #d4d4d8;
  --text-primary: #09090b;
  --text-secondary: #52525b;
  --text-muted: #a1a1aa;
  --accent: #3f3f46;
  --accent-hover: #18181b;
  --accent-dim: rgba(63, 63, 70, 0.06);
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.08);
}

/* ============================================
   RESET
   ============================================ */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg);
  color: var(--text-secondary);
  line-height: 1.7;
  overflow-x: hidden;
  font-size: 1rem;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  transition: background-color 0.4s ease, color 0.3s ease;
}

/* ============================================
   TYPOGRAPHY
   ============================================ */
h1, h2, h3, h4, h5 {
  font-family: var(--font-sans);
  font-weight: 700;
  line-height: 1.2;
  color: var(--text-primary);
  letter-spacing: -0.02em;
}

a {
  text-decoration: none;
  color: inherit;
  transition: color var(--duration-normal) var(--ease-in-out);
}

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

ul { list-style: none; }

/* Scrollbar */
::-webkit-scrollbar { width: 5px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--text-muted); }