/* ==========================================================================
   CSS Custom Properties (CSS Variables)
   ========================================================================== */

:root {
  /* Colors */
  --primary-color: #2c5aa0;
  --primary-light: #4a7bc8;
  --primary-dark: #1e3f73;
  --secondary-color: #f39c12;
  --secondary-light: #f5b041;
  --secondary-dark: #d68910;
  
  --accent-color: #e74c3c;
  --accent-light: #ec7063;
  --accent-dark: #c0392b;
  
  --success-color: #27ae60;
  --warning-color: #f39c12;
  --error-color: #e74c3c;
  --info-color: #3498db;
  
  /* Neutral Colors */
  --white: #ffffff;
  --gray-50: #f8f9fa;
  --gray-100: #f1f3f4;
  --gray-200: #e9ecef;
  --gray-300: #dee2e6;
  --gray-400: #ced4da;
  --gray-500: #adb5bd;
  --gray-600: #6c757d;
  --gray-700: #495057;
  --gray-800: #343a40;
  --gray-900: #212529;
  --black: #000000;
  
  /* Typography */
  --font-family-primary: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  --font-family-heading: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  --font-family-mono: 'Courier New', Courier, 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-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-normal: 1.5;
  --line-height-relaxed: 1.75;
  
  /* Spacing */
  --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: 3rem;     /* 48px */
  --spacing-3xl: 4rem;     /* 64px */
  --spacing-4xl: 6rem;     /* 96px */
  --spacing-5xl: 8rem;     /* 128px */
  
  /* 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);
  
  /* Glassmorphism */
  --glass-bg: rgba(255, 255, 255, 0.1);
  --glass-border: rgba(255, 255, 255, 0.2);
  --glass-backdrop: blur(10px);
  
  /* Transitions */
  --transition-fast: 150ms ease-in-out;
  --transition-base: 250ms ease-in-out;
  --transition-slow: 350ms ease-in-out;
  
  /* Z-Index Scale */
  --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;
  
  /* Breakpoints (for reference in media queries) */
  --breakpoint-sm: 576px;
  --breakpoint-md: 768px;
  --breakpoint-lg: 992px;
  --breakpoint-xl: 1200px;
  --breakpoint-2xl: 1400px;
  
  /* Container Widths */
  --container-sm: 540px;
  --container-md: 720px;
  --container-lg: 960px;
  --container-xl: 1140px;
  --container-2xl: 1320px;
  
  /* Animation Durations */
  --duration-75: 75ms;
  --duration-100: 100ms;
  --duration-150: 150ms;
  --duration-200: 200ms;
  --duration-300: 300ms;
  --duration-500: 500ms;
  --duration-700: 700ms;
  --duration-1000: 1000ms;
  
  /* Animation Timing Functions */
  --ease-linear: linear;
  --ease-in: cubic-bezier(0.4, 0, 1, 1);
  --ease-out: cubic-bezier(0, 0, 0.2, 1);
  --ease-in-out: cubic-bezier(0.4, 0, 0.2, 1);
  --ease-bounce: cubic-bezier(0.68, -0.55, 0.265, 1.55);
}

/* Dark mode variables */
@media (prefers-color-scheme: dark) {
  :root {
    --primary-color: #4a7bc8;
    --primary-light: #6b9bd8;
    --primary-dark: #2c5aa0;
    
    --gray-50: #212529;
    --gray-100: #343a40;
    --gray-200: #495057;
    --gray-300: #6c757d;
    --gray-400: #adb5bd;
    --gray-500: #ced4da;
    --gray-600: #dee2e6;
    --gray-700: #e9ecef;
    --gray-800: #f1f3f4;
    --gray-900: #f8f9fa;
    
    --glass-bg: rgba(0, 0, 0, 0.1);
    --glass-border: rgba(255, 255, 255, 0.1);
  }
}