/* CSS Custom Properties (Variables) */

:root {
  /* Colors */
  --color-white: #FFFFFF;
  --color-gray-50: #F8F9FA;
  --color-gray-100: #E9ECEF;
  --color-gray-200: #DEE2E6;
  --color-gray-300: #CED4DA;
  --color-gray-400: #ADB5BD;
  --color-gray-500: #6C757D;
  --color-gray-600: #495057;
  --color-gray-700: #343A40;
  --color-gray-800: #212529;
  --color-gray-900: #000000;

  --color-primary: #0066CC;
  --color-primary-light: #0052A3;
  --color-primary-dark: #004080;

  --color-secondary: #6C757D;
  --color-secondary-light: #868E96;
  --color-secondary-dark: #495057;

  --color-accent: #0066CC;
  --color-success: #28A745;
  --color-warning: #FFC107;
  --color-error: #DC3545;

  --color-text: #212529;
  --color-text-light: #6C757D;
  --color-text-lighter: #ADB5BD;
  --color-text-muted: #9CA3AF;
  --color-text-inverse: #FFFFFF;

  --color-border: #DEE2E6;
  --color-border-light: #E9ECEF;
  --color-border-dark: #CED4DA;

  --color-background: #FFFFFF;
  --color-background-light: #F8F9FA;
  --color-background-dark: #F1F3F5;

  --color-overlay: rgba(0, 0, 0, 0.5);
  --color-overlay-light: rgba(0, 0, 0, 0.1);
  --color-overlay-lighter: rgba(0, 0, 0, 0.05);

  /* Typography */
  --font-family-primary: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --font-family-secondary: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --font-family-mono: 'SF Mono', Monaco, Inconsolata, 'Roboto Mono', Consolas, 'Courier New', monospace;

  --font-size-xs: 0.75rem;    /* 12px */
  --font-size-sm: 0.875rem;   /* 14px */
  --font-size-base: 1rem;     /* 16px */
  --font-size-lg: 1.125rem;   /* 18px */
  --font-size-xl: 1.25rem;    /* 20px */
  --font-size-2xl: 1.5rem;    /* 24px */
  --font-size-3xl: 1.875rem;  /* 30px */
  --font-size-4xl: 2.25rem;   /* 36px */
  --font-size-5xl: 3rem;      /* 48px */
  --font-size-6xl: 3.75rem;   /* 60px */

  --font-weight-light: 300;
  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;
  --font-weight-extrabold: 800;

  --line-height-tight: 1.25;
  --line-height-snug: 1.375;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.625;
  --line-height-loose: 2;

  --letter-spacing-tight: -0.025em;
  --letter-spacing-normal: 0;
  --letter-spacing-wide: 0.025em;
  --letter-spacing-wider: 0.05em;
  --letter-spacing-widest: 0.1em;

  /* Spacing */
  --space-0: 0;
  --space-1: 0.25rem;   /* 4px */
  --space-2: 0.5rem;    /* 8px */
  --space-3: 0.75rem;   /* 12px */
  --space-4: 1rem;      /* 16px */
  --space-5: 1.25rem;   /* 20px */
  --space-6: 1.5rem;    /* 24px */
  --space-8: 2rem;      /* 32px */
  --space-10: 2.5rem;   /* 40px */
  --space-12: 3rem;     /* 48px */
  --space-16: 4rem;     /* 64px */
  --space-20: 5rem;     /* 80px */
  --space-24: 6rem;     /* 96px */
  --space-32: 8rem;     /* 128px */
  --space-40: 10rem;    /* 160px */
  --space-48: 12rem;    /* 192px */
  --space-56: 14rem;    /* 224px */
  --space-64: 16rem;    /* 256px */

  /* Border Radius */
  --radius-none: 0;
  --radius-sm: 0.125rem;    /* 2px */
  --radius-base: 0.25rem;   /* 4px */
  --radius-md: 0.375rem;    /* 6px */
  --radius-lg: 0.5rem;      /* 8px */
  --radius-xl: 0.75rem;     /* 12px */
  --radius-2xl: 1rem;       /* 16px */
  --radius-3xl: 1.5rem;     /* 24px */
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-base: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
  --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);
  --shadow-inner: inset 0 2px 4px 0 rgba(0, 0, 0, 0.06);

  /* Z-index */
  --z-dropdown: 1000;
  --z-sticky: 1020;
  --z-fixed: 1030;
  --z-modal-backdrop: 1040;
  --z-modal: 1050;
  --z-popover: 1060;
  --z-tooltip: 1070;
  --z-toast: 1080;

  /* Transitions */
  --transition-fast: 150ms ease-in-out;
  --transition-base: 250ms ease-in-out;
  --transition-slow: 350ms ease-in-out;

  --transition-colors: color var(--transition-base) ease-in-out,
                       background-color var(--transition-base) ease-in-out,
                       border-color var(--transition-base) ease-in-out;

  --transition-transform: transform var(--transition-base) ease-in-out;

  --transition-all: all var(--transition-base) ease-in-out;

  /* Breakpoints */
  --breakpoint-sm: 640px;
  --breakpoint-md: 768px;
  --breakpoint-lg: 1024px;
  --breakpoint-xl: 1280px;
  --breakpoint-2xl: 1536px;

  /* Container */
  --container-sm: 640px;
  --container-md: 768px;
  --container-lg: 1024px;
  --container-xl: 1280px;
  --container-2xl: 1400px;

  /* Focus */
  --focus-width: 2px;
  --focus-color: var(--color-primary);
  --focus-style: solid;
  --focus-offset: 2px;
}

/* Dark mode variables */
@media (prefers-color-scheme: dark) {
  :root {
    --color-text: #FFFFFF;
    --color-text-light: #ADB5BD;
    --color-text-lighter: #868E96;
    --color-text-inverse: #000000;

    --color-background: #121212;
    --color-background-light: #1E1E1E;
    --color-background-dark: #2D2D2D;

    --color-border: #2D2D2D;
    --color-border-light: #3D3D3D;
    --color-border-dark: #4D4D4D;

    --color-overlay: rgba(255, 255, 255, 0.1);
    --color-overlay-light: rgba(255, 255, 255, 0.05);
    --color-overlay-lighter: rgba(255, 255, 255, 0.025);
  }
}