/**
 * Navigation Theme CSS
 * Global styles for the new navigation system
 * Ensures consistency across homepage, lessons, and sidebar
 */

:root {
    /* Primary Brand Colors */
    --nav-primary: #9b51e0;
    --nav-primary-dark: #7a3fb8;
    --nav-primary-light: #b87ee6;
    --nav-secondary: #3498db;
    --nav-secondary-dark: #2980b9;

    /* Success & Status Colors */
    --nav-success: #27ae60;
    --nav-warning: #f39c12;
    --nav-error: #e74c3c;
    --nav-info: #3498db;

    /* Neutral Colors */
    --nav-white: #ffffff;
    --nav-black: #000000;
    --nav-gray-darkest: #2c3e50;
    --nav-gray-dark: #34495e;
    --nav-gray-medium: #7f8c8d;
    --nav-gray-light: #ecf0f1;
    --nav-gray-lightest: #f5f5f5;
    --nav-text: #333333;
    --nav-text-light: #666666;

    /* Spacing System */
    --nav-space-xs: 0.25rem;
    --nav-space-sm: 0.5rem;
    --nav-space-md: 1rem;
    --nav-space-lg: 1.5rem;
    --nav-space-xl: 2rem;
    --nav-space-xxl: 3rem;

    /* Typography */
    --nav-font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --nav-font-size-xs: 0.75rem;
    --nav-font-size-sm: 0.875rem;
    --nav-font-size-base: 1rem;
    --nav-font-size-lg: 1.125rem;
    --nav-font-size-xl: 1.25rem;
    --nav-font-size-xxl: 1.5rem;
    --nav-font-size-huge: 2rem;

    /* Border Radius */
    --nav-radius-sm: 4px;
    --nav-radius-md: 8px;
    --nav-radius-lg: 12px;
    --nav-radius-xl: 16px;
    --nav-radius-pill: 50px;

    /* Shadows */
    --nav-shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.1);
    --nav-shadow-md: 0 4px 8px rgba(0, 0, 0, 0.12);
    --nav-shadow-lg: 0 8px 16px rgba(0, 0, 0, 0.15);
    --nav-shadow-xl: 0 12px 24px rgba(0, 0, 0, 0.18);

    /* Transitions */
    --nav-transition-fast: 0.15s ease;
    --nav-transition-base: 0.3s ease;
    --nav-transition-slow: 0.5s ease;

    /* Z-index layers */
    --nav-z-base: 1;
    --nav-z-dropdown: 100;
    --nav-z-sticky: 200;
    --nav-z-overlay: 900;
    --nav-z-modal: 1000;
    --nav-z-notification: 1100;
}

/* ============================================================================
   Global Resets & Base Styles
   ============================================================================ */

* {
    box-sizing: border-box;
}

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    margin: 0;
    padding: 0;
    font-family: var(--nav-font-family);
    font-size: var(--nav-font-size-base);
    line-height: 1.6;
    color: var(--nav-text);
    background: var(--nav-white);
}

/* ============================================================================
   Typography Utilities
   ============================================================================ */

.nav-heading-1 {
    font-size: var(--nav-font-size-huge);
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: var(--nav-space-lg);
}

.nav-heading-2 {
    font-size: var(--nav-font-size-xxl);
    font-weight: 600;
    line-height: 1.3;
    margin-bottom: var(--nav-space-md);
}

.nav-heading-3 {
    font-size: var(--nav-font-size-xl);
    font-weight: 600;
    line-height: 1.4;
    margin-bottom: var(--nav-space-md);
}

.nav-text-small {
    font-size: var(--nav-font-size-sm);
}

.nav-text-large {
    font-size: var(--nav-font-size-lg);
}

/* ============================================================================
   Button Styles
   ============================================================================ */

.nav-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--nav-space-sm);
    padding: var(--nav-space-lg) var(--nav-space-xxl);
    font-size: var(--nav-font-size-lg);
    font-weight: 600;
    line-height: 1;
    text-decoration: none;
    border: none;
    border-radius: var(--nav-radius-md);
    cursor: pointer;
    transition: all var(--nav-transition-base);
    font-family: inherit;
    min-width: 180px;
}

.nav-button-primary {
    background: linear-gradient(135deg, var(--nav-primary) 0%, var(--nav-secondary) 100%);
    color: var(--nav-white);
    box-shadow: var(--nav-shadow-md);
}

.nav-button-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--nav-shadow-lg);
}

.nav-button-primary:active {
    transform: translateY(0);
    box-shadow: var(--nav-shadow-sm);
}

.nav-button-secondary {
    background: var(--nav-gray-light);
    color: var(--nav-text);
    box-shadow: var(--nav-shadow-sm);
}

.nav-button-secondary:hover {
    background: var(--nav-gray-medium);
    color: var(--nav-white);
}

/* ============================================================================
   Card Styles
   ============================================================================ */

.nav-card {
    background: var(--nav-white);
    border-radius: var(--nav-radius-lg);
    padding: var(--nav-space-xl);
    box-shadow: var(--nav-shadow-md);
    transition: box-shadow var(--nav-transition-base);
}

.nav-card:hover {
    box-shadow: var(--nav-shadow-lg);
}

.nav-card-body {
    padding: var(--nav-space-lg);
}

/* ============================================================================
   Badge & Tag Styles
   ============================================================================ */

.nav-badge {
    display: inline-flex;
    align-items: center;
    padding: var(--nav-space-xs) var(--nav-space-sm);
    font-size: var(--nav-font-size-xs);
    font-weight: 600;
    border-radius: var(--nav-radius-pill);
    background: var(--nav-gray-light);
    color: var(--nav-text);
}

.nav-badge-success {
    background: var(--nav-success);
    color: var(--nav-white);
}

.nav-badge-primary {
    background: var(--nav-primary);
    color: var(--nav-white);
}

/* ============================================================================
   Loading & Skeleton Styles
   ============================================================================ */

.nav-loading-spinner {
    display: inline-block;
    width: 40px;
    height: 40px;
    border: 4px solid var(--nav-gray-light);
    border-top-color: var(--nav-primary);
    border-radius: 50%;
    animation: nav-spin 0.8s linear infinite;
}

@keyframes nav-spin {
    to {
        transform: rotate(360deg);
    }
}

.nav-skeleton {
    background: linear-gradient(
        90deg,
        var(--nav-gray-lightest) 25%,
        var(--nav-gray-light) 50%,
        var(--nav-gray-lightest) 75%
    );
    background-size: 200% 100%;
    animation: nav-skeleton-loading 1.5s ease-in-out infinite;
    border-radius: var(--nav-radius-sm);
}

@keyframes nav-skeleton-loading {
    0% {
        background-position: 200% 0;
    }
    100% {
        background-position: -200% 0;
    }
}

/* ============================================================================
   Utility Classes
   ============================================================================ */

/* Spacing utilities */
.nav-mt-0 { margin-top: 0; }
.nav-mt-1 { margin-top: var(--nav-space-sm); }
.nav-mt-2 { margin-top: var(--nav-space-md); }
.nav-mt-3 { margin-top: var(--nav-space-lg); }
.nav-mt-4 { margin-top: var(--nav-space-xl); }

.nav-mb-0 { margin-bottom: 0; }
.nav-mb-1 { margin-bottom: var(--nav-space-sm); }
.nav-mb-2 { margin-bottom: var(--nav-space-md); }
.nav-mb-3 { margin-bottom: var(--nav-space-lg); }
.nav-mb-4 { margin-bottom: var(--nav-space-xl); }

/* Text alignment */
.nav-text-left { text-align: left; }
.nav-text-center { text-align: center; }
.nav-text-right { text-align: right; }

/* Display utilities */
.nav-hidden { display: none !important; }
.nav-visible { display: block !important; }

/* Flexbox utilities */
.nav-flex { display: flex; }
.nav-flex-column { flex-direction: column; }
.nav-flex-center { justify-content: center; align-items: center; }
.nav-flex-between { justify-content: space-between; }
.nav-flex-wrap { flex-wrap: wrap; }

/* ============================================================================
   Accessibility Improvements
   ============================================================================ */

/* Focus states */
*:focus-visible {
    outline: 3px solid var(--nav-primary);
    outline-offset: 2px;
}

/* Skip to content link */
.nav-skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--nav-primary);
    color: var(--nav-white);
    padding: var(--nav-space-sm) var(--nav-space-md);
    text-decoration: none;
    z-index: var(--nav-z-notification);
}

.nav-skip-link:focus {
    top: 0;
}

/* Screen reader only content */
.nav-sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}

/* ============================================================================
   Print Styles
   ============================================================================ */

@media print {
    .nav-button,
    .nav-skip-link,
    .nav-loading-spinner {
        display: none !important;
    }

    .nav-card {
        box-shadow: none;
        border: 1px solid var(--nav-gray-light);
    }

    body {
        font-size: 12pt;
        line-height: 1.5;
    }
}

/* ============================================================================
   Dark Mode Support (Optional)
   ============================================================================ */

@media (prefers-color-scheme: dark) {
    /* Only apply if user hasn't explicitly set light mode */
    body:not(.force-light-mode) {
        /* Dark mode would go here if needed */
        /* Currently not implemented per design requirements */
    }
}