:root {
  /* Layout */
  --max-width: none;
  --content-padding: 16px;
  --radius-sm: 6px;
  --radius: 12px;
  --radius-lg: 16px;

  /* Typography */
  --font-sans: 'Segoe UI', system-ui, -apple-system, sans-serif;
  --font-mono: 'Cascadia Code', 'Fira Code', 'JetBrains Mono', monospace;
  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.5rem;
  --text-2xl: 2rem;
  --text-3xl: 2.5rem;

  /* Spacing */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 40px;
  --space-2xl: 64px;

  /* Animation */
  --duration-fast: 150ms;
  --duration-normal: 250ms;
  --duration-slow: 400ms;
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);

  /* Surface colors (light mode — default) */
  --color-bg: #ffffff;
  --color-surface: #f8f9fa;
  --color-surface2: #e9ecef;
  --color-border: #dee2e6;
  --color-text: #212529;
  --color-text2: #6c757d;
  --color-text3: #adb5bd;

  /* Tool-specific (overridden per tool) */
  --tool-primary: #6c5ce7;
  --tool-accent: #00b894;

  /* Status colors */
  --color-success: #00b894;
  --color-warning: #fdcb6e;
  --color-error: #e17055;
  --color-info: #74b9ff;

  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
  --shadow: 0 4px 16px rgba(0,0,0,0.1);
  --shadow-lg: 0 8px 32px rgba(0,0,0,0.12);
}

:root.dark {
  --color-bg: #0f0f1a;
  --color-surface: #1a1a2e;
  --color-surface2: #222240;
  --color-border: #2d2d50;
  --color-text: #e8e8f0;
  --color-text2: #a0a0b8;
  --color-text3: #6c6c88;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.3);
  --shadow: 0 4px 16px rgba(0,0,0,0.4);
  --shadow-lg: 0 8px 32px rgba(0,0,0,0.5);
}