:root {
    /* Colors */
    --color-primary: #007bff;
    --color-secondary: #6c757d;
    --color-success: #28a745;
    --color-error: #dc3545;
    --color-warning: #ffc107;
    --color-info: #17a2b8;
    
    --color-background-light: #ffffff;
    --color-background-dark: #343a40;
    
    --color-text-primary: #212529;
    --color-text-secondary: #6c757d;
    --color-text-light: #f8f9fa;
    --color-text-dark: #343a40;
    
    --border-color: #dee2e6;
    
    /* Spacing */
    --spacing-xs: 0.25rem;  /* 4px */
    --spacing-sm: 0.5rem;   /* 8px */
    --spacing-md: 1rem;     /* 16px */
    --spacing-lg: 1.5rem;   /* 24px */
    --spacing-xl: 2rem;     /* 32px */
    
    /* Border radius */
    --border-radius-sm: 0.25rem;
    --border-radius-md: 0.375rem;
    --border-radius-lg: 0.5rem;
    
    /* 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);
    
    /* Font sizes */
    --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 */
    
    /* Line heights */
    --line-height-tight: 1.25;
    --line-height-snug: 1.375;
    --line-height-normal: 1.5;
    --line-height-relaxed: 1.625;
    --line-height-loose: 2;
    
    /* Font weights */
    --font-weight-light: 300;
    --font-weight-normal: 400;
    --font-weight-medium: 500;
    --font-weight-semibold: 600;
    --font-weight-bold: 700;
    
    /* Z-index */
    --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;
    
    /* Transitions */
    --transition-base: all 0.2s ease-in-out;
    --transition-fast: all 0.15s ease-in-out;
    --transition-slow: all 0.3s ease-in-out;
}