:root {
  /* Colors — Light Mode (default) */
  --color-bg: #FAFAF7;
  --color-surface: #FFFFFF;
  --color-text-primary: #1A1A1A;
  --color-text-secondary: #5A5A5A;
  --color-accent: #6B6B2E;
  --color-accent-hover: #7D7D3A;
  --color-border: #E5E5E0;
  --shadow-card: 0 1px 3px rgba(0, 0, 0, 0.08), 0 1px 2px rgba(0, 0, 0, 0.06);
  --shadow-card-hover: 0 4px 12px rgba(0, 0, 0, 0.1);

  /* Spacing */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;

  /* Typography */
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-size-base: 1rem;
  --font-size-sm: 0.875rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 2rem;
  --line-height-base: 1.6;
  --line-height-tight: 1.3;
  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-bold: 700;
  --letter-spacing-base: 0;

  /* Layout */
  --container-max-width: 960px;
  --container-padding: 1rem;
  --navbar-height: 56px;
  --border-radius: 12px;
  --border-radius-sm: 8px;

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
}

/* Dark Mode */
[data-theme="dark"] {
  --color-bg: #131313;
  --color-surface: #1E1E1E;
  --color-text-primary: #E8E8E3;
  --color-text-secondary: #9A9A95;
  --color-accent: #A3A352;
  --color-accent-hover: #B5B564;
  --color-border: #2A2A2A;
  --shadow-card: 0 1px 3px rgba(0, 0, 0, 0.3), 0 1px 2px rgba(0, 0, 0, 0.2);
  --shadow-card-hover: 0 4px 12px rgba(0, 0, 0, 0.4);
}

/* Large Text Mode */
[data-text-size="large"] {
  --font-size-base: 1.375rem;
  --font-size-sm: 1.125rem;
  --font-size-lg: 1.5rem;
  --font-size-xl: 1.75rem;
  --font-size-2xl: 2rem;
  --font-size-3xl: 2.5rem;
  --line-height-base: 1.8;
  --font-weight-normal: 450;
  --letter-spacing-base: 0.01em;
}