:root {
  /* Brand */
  --color-brand: #6366f1;
  --color-brand-hover: #5558e8;
  --color-brand-subtle: rgba(99, 102, 241, 0.1);
  --color-brand-subtle-hover: rgba(99, 102, 241, 0.15);

  /* Semantic */
  --color-success: #10b981;
  --color-success-subtle: rgba(16, 185, 129, 0.12);
  --color-warning: #f59e0b;
  --color-warning-subtle: rgba(245, 158, 11, 0.12);
  --color-danger: #ef4444;
  --color-danger-subtle: rgba(239, 68, 68, 0.12);

  /* Surfaces */
  --color-bg: #fafafa;
  --color-surface: #ffffff;
  --color-surface-raised: #f4f4f5;
  --color-surface-hover: #ededed;
  --color-border: #e4e4e7;
  --color-border-strong: #d4d4d8;

  /* Text */
  --color-text: #18181b;
  --color-text-secondary: #52525b;
  --color-text-muted: #a1a1aa;
  --color-text-inverse: #ffffff;

  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  --text-xs: 11px;
  --text-sm: 13px;
  --text-base: 14px;
  --text-md: 15px;
  --text-lg: 18px;
  --text-xl: 24px;
  --text-2xl: 32px;

  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;

  --line-height-tight: 1.25;
  --line-height-normal: 1.5;

  /* Spacing (4px base) */
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 24px;
  --space-6: 32px;
  --space-7: 48px;
  --space-8: 64px;

  /* Radius */
  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 8px;
  --radius-xl: 12px;

  /* Elevation */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 2px 8px rgba(0, 0, 0, 0.06);

  /* Transitions */
  --transition-fast: 100ms ease;
  --transition-base: 150ms ease;

  /* Layout */
  --max-width: 1200px;
  --sidebar-width: 240px;
}

/* Dark mode */
[data-theme="dark"] {
  --color-bg: #09090b;
  --color-surface: #111113;
  --color-surface-raised: #1a1a1d;
  --color-surface-hover: #222226;
  --color-border: rgba(255, 255, 255, 0.08);
  --color-border-strong: rgba(255, 255, 255, 0.14);
  --color-text: #fafafa;
  --color-text-secondary: rgba(250, 250, 250, 0.7);
  --color-text-muted: rgba(250, 250, 250, 0.45);
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 2px 8px rgba(0, 0, 0, 0.4);
}