:root {
    /* ============================================
       COLOR PALETTE - Semantic Colors
       ============================================ */

    /* Primary - Navy Blue (Main brand color) - ADA Compliant */
    --color-primary: #25476a;
    --color-primary-hover: #1d3856;
    --color-primary-light: #e9edf2;
    --color-primary-dark: #162b42;

    /* Secondary - Blue (5.49:1 on white, 4.82:1 on light) */
    --color-secondary: #1a6fa0;
    --color-secondary-hover: #14608a;
    --color-secondary-light: #e6f2f9;

    /* Status Colors - ADA Compliant, derived from primary navy (#25476a) */
    --color-success: #357a5e;        /* 5.13:1 on white, 4.53:1 on light */
    --color-success-light: #eaf3ef;
    --color-warning: #866a22;        /* 5.12:1 on white, 4.63:1 on light */
    --color-warning-light: #faf3e3;
    --color-danger: #b5433f;         /* 5.47:1 on white, 4.67:1 on light */
    --color-danger-light: #f8eaea;
    --color-info: #337296;           /* 5.27:1 on white, 4.61:1 on light */
    --color-info-light: #e9f1f7;

    /* Neutral Colors */
    --color-dark: #313a46;
    --color-gray-900: #343a40;
    --color-gray-800: #495057;
    --color-gray-700: #6c757d;
    --color-gray-600: #868e96;
    --color-gray-500: #adb5bd;
    --color-gray-400: #ced4da;
    --color-gray-300: #dee2e6;
    --color-gray-200: #e9ecef;
    --color-gray-100: #f8f9fa;
    --color-light: #eef2f7;
    --color-white: #ffffff;

    /* Background Colors */
    --bg-primary: var(--color-primary-light);
    --bg-secondary: var(--color-secondary-light);
    --bg-success: var(--color-success-light);
    --bg-warning: var(--color-warning-light);
    --bg-danger: var(--color-danger-light);
    --bg-info: var(--color-info-light);
    --bg-light: var(--color-gray-100);
    --bg-dark: var(--color-dark);

    /* Opacity Variants */
    --opacity-10: 0.1;
    --opacity-15: 0.15;
    --opacity-25: 0.25;
    --opacity-50: 0.5;
    --opacity-75: 0.75;


    /* ============================================
       TYPOGRAPHY
       ============================================ */

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

    /* 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 */

    /* Font Weights */
    --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 Heights */
    --line-height-tight: 1.25;
    --line-height-snug: 1.375;
    --line-height-base: 1.5;
    --line-height-relaxed: 1.75;
    --line-height-loose: 2;

    /* Letter Spacing */
    --letter-spacing-tight: -0.025em;
    --letter-spacing-normal: 0;
    --letter-spacing-wide: 0.025em;
    --letter-spacing-wider: 0.05em;
    --letter-spacing-widest: 0.1em;


    /* ============================================
       SPACING SYSTEM (8px base unit)
       ============================================ */

    --space-0: 0;
    --space-1: 0.25rem; /* 4px */
    --space-2: 0.5rem; /* 8px */
    --space-3: 0.75rem; /* 12px */
    --space-4: 1rem; /* 16px */
    --space-5: 1.5rem; /* 24px */
    --space-6: 2rem; /* 32px */
    --space-7: 2.5rem; /* 40px */
    --space-8: 3rem; /* 48px */
    --space-9: 3.5rem; /* 56px */
    --space-10: 4rem; /* 64px */
    --space-12: 6rem; /* 96px */
    --space-16: 8rem; /* 128px */


    /* ============================================
       BORDER RADIUS
       ============================================ */

    --radius-none: 0;
    --radius-sm: 0.25rem; /* 4px */
    --radius-base: 0.375rem; /* 6px */
    --radius-md: 0.3rem; /* 8px */
    --radius-lg: 0.5rem; /* 12px */
    --radius-xl: 1rem; /* 16px */
    --radius-2xl: 1.5rem; /* 24px */
    --radius-full: 9999px;


    /* ============================================
       SHADOWS
       ============================================ */

    --shadow-xs: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --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);
    --shadow-none: none;

    /* Colored Shadows */
    --shadow-primary: 0 4px 6px -1px rgba(37, 71, 106, 0.2), 0 2px 4px -1px rgba(37, 71, 106, 0.1);
    --shadow-danger: 0 4px 6px -1px rgba(181, 67, 63, 0.2), 0 2px 4px -1px rgba(181, 67, 63, 0.1);
    --shadow-warning: 0 4px 6px -1px rgba(134, 106, 34, 0.2), 0 2px 4px -1px rgba(134, 106, 34, 0.1);


    /* ============================================
       TRANSITIONS & ANIMATIONS
       ============================================ */

    --transition-fast: 150ms ease-in-out;
    --transition-base: 250ms ease-in-out;
    --transition-slow: 350ms ease-in-out;
    --transition-slower: 500ms ease-in-out;

    /* Easing Functions */
    --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);


    /* ============================================
       Z-INDEX SCALE
       ============================================ */

    --z-base: 0;
    --z-dropdown: 1000;
    --z-sticky: 1020;
    --z-fixed: 1030;
    --z-offcanvas: 1040;
    --z-modal-backdrop: 1040;
    --z-modal: 1050;
    --z-popover: 1060;
    --z-tooltip: 1070;


    /* ============================================
       BREAKPOINTS (for reference in JS)
       ============================================ */

    --breakpoint-xs: 0;
    --breakpoint-sm: 576px;
    --breakpoint-md: 768px;
    --breakpoint-lg: 992px;
    --breakpoint-xl: 1200px;
    --breakpoint-xxl: 1400px;


    /* ============================================
       COMPONENT-SPECIFIC TOKENS
       ============================================ */

    /* Cards */
    --card-padding: var(--space-5);
    --card-border-radius: var(--radius-lg);
    --card-border-color: var(--color-gray-300);
    --card-shadow: var(--shadow-base);

    /* Buttons */
    --button-padding-y: var(--space-2);
    --button-padding-x: var(--space-4);
    --button-border-radius: var(--radius-base);
    --button-font-weight: var(--font-weight-semibold);
    --button-transition: all var(--transition-base);

    /* Forms */
    --input-padding-y: var(--space-2);
    --input-padding-x: var(--space-3);
    --input-border-radius: var(--radius-base);
    --input-border-color: var(--color-gray-300);
    --input-focus-border-color: var(--color-primary);
    --input-focus-shadow: 0 0 0 3px var(--color-primary-light);

    /* Tables */
    --table-cell-padding-y: var(--space-3);
    --table-cell-padding-x: var(--space-4);
    --table-border-color: var(--color-gray-300);
    --table-hover-bg: var(--color-primary-light);

    /* Navigation */
    --nav-link-padding-y: var(--space-3);
    --nav-link-padding-x: var(--space-4);
    --nav-link-color: var(--color-gray-700);
    --nav-link-hover-color: var(--color-primary);

    /* Avatar Sizes */
    --avatar-xs: 24px;
    --avatar-sm: 32px;
    --avatar-base: 40px;
    --avatar-md: 56px;
    --avatar-lg: 72px;
    --avatar-xl: 96px;
}

/* ============================================
   DARK MODE SUPPORT (Future Enhancement)
   ============================================ */

@media (prefers-color-scheme: dark) {
    /* Uncomment when implementing dark mode
    :root {
      --color-dark: #ffffff;
      --color-white: #1a1a1a;
      --color-gray-900: #f8f9fa;
      --color-gray-100: #343a40;
      ... etc
    }
    */
}

/* ============================================
   UTILITY HELPER CLASSES
   ============================================ */

/* Subtle background variants */
.bg-primary-subtle {
    background-color: var(--color-primary-light) !important;
}

.bg-secondary-subtle {
    background-color: var(--color-secondary-light) !important;
}

.bg-success-subtle {
    background-color: var(--color-success-light) !important;
}

.bg-warning-subtle {
    background-color: var(--color-warning-light) !important;
}

.bg-danger-subtle {
    background-color: var(--color-danger-light) !important;
}

.bg-info-subtle {
    background-color: var(--color-info-light) !important;
}

/* Text color variants */
.text-primary {
    color: var(--color-primary) !important;
}

.text-secondary {
    color: var(--color-secondary) !important;
}

.text-success {
    color: var(--color-success) !important;
}

.text-warning {
    color: var(--color-warning) !important;
}

.text-danger {
    color: var(--color-danger) !important;
}

.text-info {
    color: var(--color-info) !important;
}

.text-muted {
    color: var(--color-gray-700) !important;
}

/* Border color variants */
.border-primary {
    border-color: var(--color-primary) !important;
}

.border-secondary {
    border-color: var(--color-secondary) !important;
}

.border-success {
    border-color: var(--color-success) !important;
}

.border-warning {
    border-color: var(--color-warning) !important;
}

.border-danger {
    border-color: var(--color-danger) !important;
}

.border-info {
    border-color: var(--color-info) !important;
}