/**
 * CSS Variables - Design Tokens
 *
 * Defines all CSS custom properties (variables) for consistent theming.
 * Can be easily extended for dark mode by overriding in @media (prefers-color-scheme: dark).
 */

:root {
    /* Colors - Primary Palette */
    --color-primary: #3b82f6;
    --color-primary-dark: #2563eb;
    --color-primary-light: #60a5fa;
    --color-primary-lightest: #dbeafe;

    /* Colors - Secondary Palette */
    --color-secondary: #8b5cf6;
    --color-secondary-dark: #7c3aed;
    --color-secondary-light: #a78bfa;

    /* Colors - Neutrals */
    --color-gray-50: #f9fafb;
    --color-gray-100: #f3f4f6;
    --color-gray-200: #e5e7eb;
    --color-gray-300: #d1d5db;
    --color-gray-400: #9ca3af;
    --color-gray-500: #6b7280;
    --color-gray-600: #4b5563;
    --color-gray-700: #374151;
    --color-gray-800: #1f2937;
    --color-gray-900: #111827;

    /* Colors - Semantic */
    --color-success: #10b981;
    --color-success-light: #d1fae5;
    --color-warning: #f59e0b;
    --color-warning-light: #fef3c7;
    --color-error: #ef4444;
    --color-error-light: #fee2e2;
    --color-info: #3b82f6;
    --color-info-light: #dbeafe;

    /* Colors - Background */
    --color-bg: #ffffff;
    --color-bg-alt: var(--color-gray-50);
    --color-bg-overlay: rgba(0, 0, 0, 0.5);

    /* Colors - Text */
    --color-text: var(--color-gray-900);
    --color-text-muted: var(--color-gray-600);
    --color-text-light: var(--color-gray-500);

    /* Colors - Border */
    --color-border: var(--color-gray-200);
    --color-border-dark: var(--color-gray-300);

    /* Typography - Font Families */
    --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    --font-mono: "SF Mono", Monaco, "Cascadia Code", "Roboto Mono", Consolas, "Courier New", monospace;

    /* Typography - 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 */
    --font-size-5xl: 3rem;        /* 48px */

    /* Typography - Font Weights */
    --font-weight-normal: 400;
    --font-weight-medium: 500;
    --font-weight-semibold: 600;
    --font-weight-bold: 700;

    /* Typography - Line Heights */
    --line-height-tight: 1.25;
    --line-height-normal: 1.5;
    --line-height-relaxed: 1.75;

    /* Spacing Scale */
    --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 */

    /* Border Radius */
    --radius-sm: 0.25rem;    /* 4px */
    --radius-md: 0.375rem;   /* 6px */
    --radius-lg: 0.5rem;     /* 8px */
    --radius-xl: 0.75rem;    /* 12px */
    --radius-2xl: 1rem;      /* 16px */
    --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: 200ms ease-in-out;
    --transition-slow: 300ms 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;

    /* Layout */
    --container-max-width: 1200px;
    --header-height: 64px;
    --footer-height: 80px;

    /* Form Controls */
    --input-height: 2.5rem;      /* 40px */
    --input-height-sm: 2rem;     /* 32px */
    --input-height-lg: 3rem;     /* 48px */
}

/* Dark Mode Support (optional, can be extended later) */
@media (prefers-color-scheme: dark) {
    /*
    :root {
        --color-bg: var(--color-gray-900);
        --color-bg-alt: var(--color-gray-800);
        --color-text: var(--color-gray-100);
        --color-text-muted: var(--color-gray-400);
        --color-border: var(--color-gray-700);
    }
    */
}