:root {
  /* Primary Colors */
  --color-primary-50: #fff3e0;
  --color-primary-100: #ffe0b2;
  --color-primary-200: #ffcc80;
  --color-primary-300: #ffb74d;
  --color-primary-400: #ffa726;
  --color-primary-500: #ff6b35;
  --color-primary-600: #fb8c00;
  --color-primary-700: #e64a19;
  --color-primary-800: #ef6c00;
  --color-primary-900: #e65100;

  /* Secondary Colors */
  --color-secondary-500: #9c27b0;
  --color-secondary-600: #8e24aa;
  --color-secondary-700: #7b1fa2;
  --color-secondary-900: #4a148c;

  /* Neutral Colors */
  --color-neutral-0: #ffffff;
  --color-neutral-50: #fafafa;
  --color-neutral-100: #f5f5f5;
  --color-neutral-200: #eeeeee;
  --color-neutral-300: #e0e0e0;
  --color-neutral-400: #bdbdbd;
  --color-neutral-500: #9e9e9e;
  --color-neutral-600: #757575;
  --color-neutral-700: #424242;
  --color-neutral-800: #212121;
  --color-neutral-900: #121212;

  /* Semantic Colors */
  --color-success: #4caf50;
  --color-warning: #ffc107;
  --color-error: #ef5350;
  --color-info: #2196f3;

  /* Gradients */
  --gradient-primary: linear-gradient(
    135deg,
    var(--color-primary-500),
    var(--color-primary-700)
  );
  --gradient-secondary: linear-gradient(
    135deg,
    var(--color-secondary-500),
    var(--color-secondary-700)
  );
  --gradient-sunset: linear-gradient(
    135deg,
    var(--color-primary-500),
    #ff8e53,
    var(--color-warning)
  );
  --gradient-cool: linear-gradient(135deg, #667eea, #764ba2);
  --gradient-soft: linear-gradient(135deg, #f5f7fa, #c3cfe2);

  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  --spacing-3xl: 4rem;
  --spacing-4xl: 6rem;

  /* Typography */
  --font-family-base: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto',
    'Oxygen', 'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue',
    sans-serif;
  --font-family-heading: 'Noto Sans JP', -apple-system, BlinkMacSystemFont,
    'Segoe UI', sans-serif;

  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  --text-3xl: 1.875rem;
  --text-4xl: 2.25rem;
  --text-5xl: 3rem;
  --text-6xl: 3.75rem;

  --font-weight-light: 300;
  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;

  --line-height-tight: 1.2;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.75;

  /* Border Radius */
  --radius-sm: 0.25rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-2xl: 1.5rem;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1),
    0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1),
    0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1),
    0 10px 10px -5px rgba(0, 0, 0, 0.04);
  --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);

  /* Transitions */
  --transition-fast: 150ms ease-in-out;
  --transition-base: 200ms ease-in-out;
  --transition-slow: 300ms ease-in-out;

  /* Z-index */
  --z-dropdown: 1000;
  --z-sticky: 1020;
  --z-fixed: 1030;
  --z-modal-backdrop: 1040;
  --z-modal: 1050;
  --z-popover: 1060;
  --z-tooltip: 1070;

  /* Container */
  --container-max-width: 1200px;
  --container-padding: var(--spacing-lg);
}

/* Dark mode support */
@media (prefers-color-scheme: dark) {
  :root {
    --color-neutral-0: #121212;
    --color-neutral-50: #1e1e1e;
    --color-neutral-100: #2c2c2c;
    --color-neutral-200: #3a3a3a;
    --color-neutral-900: #ffffff;
  }
}