/* =============================================================================
   CSS VARIABLES & DESIGN TOKENS
   ============================================================================= */

:root {
    /* Color Palette - Professional Psychology Practice */
    --color-primary: #2c3e50;        /* Deep blue-grey */
    --color-secondary: #3498db;      /* Light blue */
    --color-accent: #16a085;         /* Teal/green */
    --color-success: #27ae60;         /* Green */
    --color-warning: #f39c12;         /* Orange */
    --color-danger: #e74c3c;          /* Red */
    
    --color-bg-light: #f8f9fa;       /* Off-white background */
    --color-bg-dark: #ffffff;        /* White content background */
    --color-text-primary: #2c3e50;   /* Dark text */
    --color-text-secondary: #7f8c8d; /* Grey text */
    --color-border: #ecf0f1;         /* Light border */
    
    /* Typography */
    --font-family-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 
                        'Helvetica Neue', Arial, sans-serif;
    --font-family-serif: 'Georgia', 'Garamond', serif;
    
    --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: 1.5rem;      /* 24px */
    --font-size-2xl: 2rem;       /* 32px */
    --font-size-3xl: 2.5rem;     /* 40px */
    
    --font-weight-light: 300;
    --font-weight-normal: 400;
    --font-weight-semibold: 600;
    --font-weight-bold: 700;
    
    /* Line Heights */
    --line-height-tight: 1.2;
    --line-height-normal: 1.5;
    --line-height-relaxed: 1.75;
    
    /* Spacing Scale - 4px base unit */
    --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 */
    
    /* Border Radius */
    --radius-sm: 0.25rem;
    --radius-md: 0.5rem;
    --radius-lg: 1rem;
    --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);
    
    /* Transitions */
    --transition-fast: 150ms ease-in-out;
    --transition-base: 250ms ease-in-out;
    --transition-slow: 350ms ease-in-out;
    
    /* Breakpoints (Mobile-first approach) */
    /* Small (sm): 640px and up */
    /* Medium (md): 768px and up */
    /* Large (lg): 1024px and up */
    /* Extra Large (xl): 1280px and up */
    /* 2X Large (2xl): 1536px and up */
    
    /* Z-index scale */
    --z-dropdown: 100;
    --z-sticky: 200;
    --z-fixed: 300;
    --z-modal: 1000;
}

/* Dark mode support (future enhancement) */
@media (prefers-color-scheme: dark) {
    :root {
        --color-bg-light: #1a1a1a;
        --color-bg-dark: #242424;
        --color-text-primary: #f8f9fa;
        --color-text-secondary: #b0b0b0;
        --color-border: #404040;
    }
}

/* High contrast mode support */
@media (prefers-contrast: more) {
    :root {
        --color-primary: #000000;
        --color-secondary: #0066cc;
        --color-text-secondary: #555555;
    }
}

/* Reduced motion support */
@media (prefers-reduced-motion: reduce) {
    :root {
        --transition-fast: 0ms;
        --transition-base: 0ms;
        --transition-slow: 0ms;
    }
}