/**
 * CSS Variables (Design Tokens) — MODULAR ARCHITECTURE (not active)
 *
 * NOTE: This file is part of the modular CSS architecture in /static/css/
 * which is NOT loaded by base.html. The active variable definitions live in:
 *   - app/static/styles.css (main stylesheet)
 *   - app/static/ui-system.css (design system tokens)
 *
 * This file is kept as reference for the planned modular migration.
 *
 * NAMING CONVENTION:
 * --{category}-{property}-{variant}
 * Examples: --color-primary-50, --space-4, --text-lg
 */

:root {
    /* =========================================================================
       COLOR PALETTE
       Semantic colors with full shade ranges
       ========================================================================= */

    /* Primary - Blue */
    --color-primary: #2563eb;
    --color-primary-50: #eff6ff;
    --color-primary-100: #dbeafe;
    --color-primary-200: #bfdbfe;
    --color-primary-300: #93c5fd;
    --color-primary-400: #60a5fa;
    --color-primary-500: #3b82f6;
    --color-primary-600: #2563eb;
    --color-primary-700: #1d4ed8;
    --color-primary-800: #1e40af;
    --color-primary-900: #1e3a8a;
    --color-primary-dark: #1d4ed8;
    --color-primary-light: #eff6ff;

    /* Success - Green */
    --color-success: #059669;
    --color-success-50: #ecfdf5;
    --color-success-100: #d1fae5;
    --color-success-200: #a7f3d0;
    --color-success-500: #10b981;
    --color-success-600: #059669;
    --color-success-700: #047857;
    --color-success-light: #d1fae5;

    /* Warning - Amber */
    --color-warning: #d97706;
    --color-warning-50: #fffbeb;
    --color-warning-100: #fef3c7;
    --color-warning-200: #fde68a;
    --color-warning-500: #f59e0b;
    --color-warning-600: #d97706;
    --color-warning-700: #b45309;
    --color-warning-900: #78350f;
    --color-warning-light: #fef3c7;

    /* Danger - Red */
    --color-danger: #dc2626;
    --color-danger-50: #fef2f2;
    --color-danger-100: #fee2e2;
    --color-danger-200: #fecaca;
    --color-danger-500: #ef4444;
    --color-danger-600: #dc2626;
    --color-danger-700: #b91c1c;
    --color-danger-light: #fee2e2;

    /* Info - Sky Blue */
    --color-info: #0284c7;
    --color-info-50: #f0f9ff;
    --color-info-100: #e0f2fe;
    --color-info-500: #0ea5e9;
    --color-info-600: #0284c7;
    --color-info-light: #e0f2fe;

    /* Neutral Grays */
    --color-gray-25: #fcfcfd;
    --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;
    --color-gray-950: #030712;

    /* =========================================================================
       SEMANTIC COLORS
       Use these for component styling
       ========================================================================= */
    --text-primary: var(--color-gray-900);
    --text-secondary: var(--color-gray-600);
    --text-tertiary: var(--color-gray-500);  /* Improved from gray-400 for WCAG AA compliance */
    --text-muted: var(--color-gray-500);
    --text-inverse: white;

    --surface-primary: white;
    --surface-secondary: var(--color-gray-50);
    --surface-tertiary: var(--color-gray-100);
    --surface-inverse: var(--color-gray-900);

    --border-color: var(--color-gray-200);
    --border-light: var(--color-gray-100);
    --border-strong: var(--color-gray-300);

    /* =========================================================================
       TYPOGRAPHY
       Font families and sizes using design system scale
       ========================================================================= */
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-mono: 'JetBrains Mono', 'SF Mono', 'Monaco', monospace;

    /* Font sizes - matches ui-system.css */
    --text-2xs: 0.6875rem;  /* 11px */
    --text-xs: 0.75rem;     /* 12px */
    --text-sm: 0.8125rem;   /* 13px */
    --text-base: 0.875rem;  /* 14px */
    --text-md: 0.9375rem;   /* 15px */
    --text-lg: 1rem;        /* 16px */
    --text-xl: 1.125rem;    /* 18px */
    --text-2xl: 1.25rem;    /* 20px */
    --text-3xl: 1.5rem;     /* 24px */
    --text-4xl: 1.875rem;   /* 30px */
    --text-5xl: 2.25rem;    /* 36px */

    /* Font weights */
    --font-normal: 400;
    --font-medium: 500;
    --font-semibold: 600;
    --font-bold: 700;

    /* Line heights */
    --leading-none: 1;
    --leading-tight: 1.2;
    --leading-snug: 1.35;
    --leading-normal: 1.5;
    --leading-relaxed: 1.625;
    --leading-loose: 2;

    /* Letter spacing */
    --tracking-tighter: -0.05em;
    --tracking-tight: -0.025em;
    --tracking-normal: 0;
    --tracking-wide: 0.025em;
    --tracking-wider: 0.05em;

    /* =========================================================================
       SPACING
       Based on 4px grid system
       ========================================================================= */
    --space-0: 0;
    --space-px: 1px;
    --space-0-5: 0.125rem;  /* 2px */
    --space-1: 0.25rem;     /* 4px */
    --space-1-5: 0.375rem;  /* 6px */
    --space-2: 0.5rem;      /* 8px */
    --space-2-5: 0.625rem;  /* 10px */
    --space-3: 0.75rem;     /* 12px */
    --space-3-5: 0.875rem;  /* 14px */
    --space-4: 1rem;        /* 16px */
    --space-5: 1.25rem;     /* 20px */
    --space-6: 1.5rem;      /* 24px */
    --space-7: 1.75rem;     /* 28px */
    --space-8: 2rem;        /* 32px */
    --space-9: 2.25rem;     /* 36px */
    --space-10: 2.5rem;     /* 40px */
    --space-12: 3rem;       /* 48px */
    --space-14: 3.5rem;     /* 56px */
    --space-16: 4rem;       /* 64px */
    --space-20: 5rem;       /* 80px */

    /* =========================================================================
       BORDER RADIUS
       ========================================================================= */
    --radius-none: 0;
    --radius-sm: 4px;
    --radius-md: 6px;
    --radius-lg: 8px;
    --radius-xl: 12px;
    --radius-2xl: 16px;
    --radius-3xl: 24px;
    --radius-full: 9999px;

    /* =========================================================================
       SHADOWS
       Softer shadows for calm UI
       ========================================================================= */
    --shadow-xs: 0 1px 2px rgba(0, 0, 0, 0.03);
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.04), 0 1px 2px rgba(0, 0, 0, 0.03);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.06), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.06), 0 4px 6px -2px rgba(0, 0, 0, 0.03);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.08), 0 10px 10px -5px rgba(0, 0, 0, 0.03);
    --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.15);

    /* Colored shadows */
    --shadow-primary: 0 4px 14px rgba(37, 99, 235, 0.25);
    --shadow-success: 0 4px 14px rgba(5, 150, 105, 0.25);
    --shadow-danger: 0 4px 14px rgba(220, 38, 38, 0.25);

    /* =========================================================================
       TRANSITIONS
       Natural-feeling ease-out timing
       ========================================================================= */
    --transition-fast: 0.1s ease-out;
    --transition-base: 0.15s ease-out;
    --transition-slow: 0.25s ease-out;
    --transition-slower: 0.35s ease-out;

    /* Composite transitions for performance (avoid 'all') */
    --transition-colors: background-color var(--transition-base), border-color var(--transition-base), color var(--transition-base);
    --transition-interactive: background-color var(--transition-base), border-color var(--transition-base), color var(--transition-base), box-shadow var(--transition-base);
    --transition-transform: transform var(--transition-base), opacity var(--transition-base);

    /* =========================================================================
       Z-INDEX SCALE
       Predictable layering system
       ========================================================================= */
    --z-below: -1;
    --z-base: 0;
    --z-raised: 10;
    --z-dropdown: 100;
    --z-sticky: 200;
    --z-fixed: 300;
    --z-overlay: 400;
    --z-modal: 500;
    --z-popover: 600;
    --z-toast: 700;
    --z-tooltip: 800;

    /* =========================================================================
       FOCUS STATES
       Accessible focus indicators
       ========================================================================= */
    --focus-ring: 0 0 0 3px rgba(37, 99, 235, 0.12);
    --focus-ring-offset: 0 0 0 2px white, 0 0 0 4px rgba(37, 99, 235, 0.4);

    /* =========================================================================
       BREAKPOINTS (for reference - can't use in media queries)
       Use these values in JS or as documentation
       ========================================================================= */
    /* --breakpoint-sm: 640px;   */
    /* --breakpoint-md: 768px;   */
    /* --breakpoint-lg: 1024px;  */
    /* --breakpoint-xl: 1280px;  */
    /* --breakpoint-2xl: 1536px; */
}