:root {
  /* Brand */
  --color-brand-primary: #7771e1;
  --color-brand-primary-hover: #6560d0;
  --color-brand-primary-subtle: rgba(119, 113, 225, 0.15);
  --color-brand-alt: #55d6c2;

  /* Surfaces */
  --color-surface-bg: #ffffff;
  --color-surface-raised: #f7f7f8;
  --color-surface-sunken: #f0f0f2;
  --color-surface-overlay: #ffffff;

  /* Text */
  --color-text-primary: #1a1a2e;
  --color-text-secondary: #5a5a72;
  --color-text-tertiary: #8e8ea0;
  --color-text-on-brand: #0a2f2a;

  /* Borders */
  --color-border-default: #d9d9e0;
  --color-border-strong: #b0b0be;
  --color-border-focus: #55d6c2;

  /* Status */
  --color-error: #9e0031;
  --color-success: #48a71e;
  --color-warning: #c97f0a;

  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
  --font-mono: 'SF Mono', SFMono-Regular, 'Cascadia Code', Consolas, monospace;

  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 2rem;

  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;

  --line-height-tight: 1.25;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.75;

  /* Spacing (4px base) */
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 20px;
  --space-6: 24px;
  --space-8: 32px;
  --space-10: 40px;
  --space-12: 48px;

  /* Radii */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.12);

  /* Transitions */
  --transition-fast: 120ms ease;
  --transition-normal: 200ms ease;
}

[data-theme="dark"] {
  /* Brand */
  --color-brand-primary: #55d6c2;
  --color-brand-primary-hover: #44c4b0;
  --color-brand-primary-subtle: rgba(85, 214, 194, 0.15);

  /* Surfaces */
  --color-surface-bg: #12121e;
  --color-surface-raised: #1e1e30;
  --color-surface-sunken: #0c0c16;
  --color-surface-overlay: #24243a;

  /* Text */
  --color-text-primary: #e8e8f0;
  --color-text-secondary: #a0a0b8;
  --color-text-tertiary: #6e6e88;

  /* Borders */
  --color-border-default: #2e2e44;
  --color-border-strong: #44445e;

  /* Status */
  --color-error: #e05577;
  --color-success: #5cc73a;

  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.5);
}