:root {
  /* Breakpoints */
  --breakpoint-mobile: 480px;
  --breakpoint-tablet: 768px;
  --breakpoint-desktop: 1200px;
  --breakpoint-wide: 1400px;

  /* Spacing Scale */
  --spacing-xs: 0.25rem; /* 4px */
  --spacing-sm: 0.5rem; /* 8px */
  --spacing-md: 1rem; /* 16px */
  --spacing-lg: 1.5rem; /* 24px */
  --spacing-xl: 2rem; /* 32px */
  --spacing-2xl: 2.5rem; /* 40px */
  --spacing-3xl: 3rem; /* 48px */

  /* Padding Scale */
  --padding-xs: 0.25rem; /* 4px */
  --padding-sm: 0.5rem; /* 8px */
  --padding-md: 1rem; /* 16px */
  --padding-lg: 1.5rem; /* 24px */
  --padding-xl: 2rem; /* 32px */
  --padding-2xl: 2.5rem; /* 40px */

  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.2s ease;
  --transition-slow: 0.3s ease;
  --transition-cubic: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-bounce: 0.3s cubic-bezier(0.68, -0.55, 0.265, 1.55);
  --transition-spring: 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);

  /* Shadows */
  --shadow-xs: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 6px 24px rgba(0, 0, 0, 0.12);
  --shadow-xl: 0 8px 32px rgba(0, 0, 0, 0.15);
  --shadow-2xl: 0 12px 48px rgba(0, 0, 0, 0.18);
  --shadow-inner: inset 0 2px 4px rgba(0, 0, 0, 0.06);

  /* Typography */
  --font-family: 'Segoe UI', system-ui, -apple-system, Arial, sans-serif;
  --font-family-mono:
    'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', Consolas, 'Courier New',
    monospace;
  --font-family-display:
    'Inter', 'Segoe UI', system-ui, -apple-system, Arial, sans-serif;

  /* Font Sizes */
  --font-size-xs: 0.75rem; /* 12px */
  --font-size-sm: 0.875rem; /* 14px */
  --font-size-base: 1rem; /* 16px */
  --font-size-md: 1.125rem; /* 18px */
  --font-size-lg: 1.25rem; /* 20px */
  --font-size-xl: 1.5rem; /* 24px */
  --font-size-2xl: 2rem; /* 32px */
  --font-size-3xl: 2.5rem; /* 40px */
  --font-size-4xl: 3rem; /* 48px */

  /* Font Weights */
  --font-weight-thin: 100;
  --font-weight-light: 300;
  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;
  --font-weight-extrabold: 800;
  --font-weight-black: 900;

  /* Line Heights */
  --line-height-tight: 1.25;
  --line-height-base: 1.5;
  --line-height-loose: 1.8;
  --line-height-relaxed: 2;

  /* Letter Spacing */
  --letter-spacing-tight: -0.025em;
  --letter-spacing-normal: 0;
  --letter-spacing-wide: 0.025em;
  --letter-spacing-wider: 0.05em;
  --letter-spacing-widest: 0.1em;

  /* Border Radius */
  --border-radius-none: 0;
  --border-radius-xs: 2px;
  --border-radius-sm: 4px;
  --border-radius-md: 8px;
  --border-radius-lg: 12px;
  --border-radius-xl: 16px;
  --border-radius-2xl: 24px;
  --border-radius-full: 9999px;

  /* Z-Index Scale */
  --z-index-hide: -1;
  --z-index-base: 0;
  --z-index-docked: 10;
  --z-index-dropdown: 1000;
  --z-index-sticky: 1020;
  --z-index-fixed: 1030;
  --z-index-modal-backdrop: 1040;
  --z-index-modal: 1050;
  --z-index-popover: 1060;
  --z-index-tooltip: 1070;
  --z-index-overlay: 9999;

  /* Opacity Scale */
  --opacity-0: 0;
  --opacity-25: 0.25;
  --opacity-50: 0.5;
  --opacity-75: 0.75;
  --opacity-100: 1;

  /* Border Widths */
  --border-width-0: 0;
  --border-width-1: 1px;
  --border-width-2: 2px;
  --border-width-4: 4px;
  --border-width-8: 8px;

  /* Aspect Ratios */
  --aspect-square: 1 / 1;
  --aspect-video: 16 / 9;
  --aspect-photo: 4 / 3;
  --aspect-golden: 1.618 / 1;

  /* Container Sizes */
  --container-xs: 20rem; /* 320px */
  --container-sm: 24rem; /* 384px */
  --container-md: 28rem; /* 448px */
  --container-lg: 32rem; /* 512px */
  --container-xl: 36rem; /* 576px */
  --container-2xl: 42rem; /* 672px */
  --container-3xl: 48rem; /* 768px */
  --container-4xl: 56rem; /* 896px */
  --container-5xl: 64rem; /* 1024px */
  --container-6xl: 72rem; /* 1152px */
  --container-7xl: 80rem; /* 1280px */
  --container-full: 100%;

  /* Animation */
  --duration-fast: 150ms;
  --duration-normal: 200ms;
  --duration-slow: 300ms;
}