/* ========================================
   CASE Learning Platform - Main Styles
   ======================================== */

/* CSS Variables */
:root {
    /* Colors */
    --primary-color: #007bff;
    --primary-dark: #0056b3;
    --primary-light: #cce7ff;
    --secondary-color: #6c757d;
    --success-color: #28a745;
    --warning-color: #ffc107;
    --danger-color: #dc3545;
    --info-color: #17a2b8;
    --light-color: #f8f9fa;
    --dark-color: #343a40;
    --white: #ffffff;
    
    /* Typography */
    --font-family-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-family-secondary: 'Poppins', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 1.875rem;
    --font-size-4xl: 2.25rem;
    --font-size-5xl: 3rem;
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    --spacing-3xl: 4rem;
    
    /* Border Radius */
    --border-radius-sm: 0.25rem;
    --border-radius-md: 0.375rem;
    --border-radius-lg: 0.5rem;
    --border-radius-xl: 0.75rem;
    --border-radius-2xl: 1rem;
    
    /* 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: 0.15s ease-in-out;
    --transition-normal: 0.3s ease-in-out;
    --transition-slow: 0.5s ease-in-out;
}

/* Global Styles */
* {
    box-sizing: border-box;
}

body {
    font-family: var(--font-family-primary);
    font-size: var(--font-size-base);
    line-height: 1.6;
    color: var(--dark-color);
    background-color: var(--white);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-family-secondary);
    font-weight: 600;
    line-height: 1.2;
    margin-bottom: var(--spacing-md);
    color: var(--dark-color);
}

h1 { font-size: var(--font-size-4xl); }
h2 { font-size: var(--font-size-3xl); }
h3 { font-size: var(--font-size-2xl); }
h4 { font-size: var(--font-size-xl); }
h5 { font-size: var(--font-size-lg); }
h6 { font-size: var(--font-size-base); }

p {
    margin-bottom: var(--spacing-md);
    color: var(--secondary-color);
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--primary-dark);
    text-decoration: underline;
}

/* Buttons */
.btn {
    font-family: var(--font-family-primary);
    font-weight: 500;
    border-radius: var(--border-radius-md);
    transition: all var(--transition-fast);
    border: none;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    text-decoration: none;
}

.btn-primary {
    background: var(--primary-color);
    color: var(--white);
    border: 2px solid var(--primary-color);
}

.btn-primary:hover {
    background: var(--primary-dark);
    border-color: var(--primary-dark);
    color: var(--white);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn-outline-primary {
    background: transparent;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

.btn-outline-primary:hover {
    background: var(--primary-color);
    color: var(--white);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn-lg {
    padding: var(--spacing-md) var(--spacing-xl);
    font-size: var(--font-size-lg);
}

.btn-sm {
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: var(--font-size-sm);
}

/* Forms */
.form-control {
    font-family: var(--font-family-primary);
    border: 2px solid #e9ecef;
    border-radius: var(--border-radius-md);
    padding: var(--spacing-md);
    transition: all var(--transition-fast);
    background-color: var(--white);
}

.form-control:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 0.2rem rgba(0, 123, 255, 0.25);
}

.form-label {
    font-weight: 500;
    color: var(--dark-color);
    margin-bottom: var(--spacing-sm);
}

/* Cards */
.card {
    border: none;
    border-radius: var(--border-radius-xl);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-normal);
    background-color: var(--white);
}

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

/* Badges */
.badge {
    font-family: var(--font-family-primary);
    font-weight: 500;
    border-radius: var(--border-radius-sm);
    padding: var(--spacing-xs) var(--spacing-sm);
}

.badge.bg-primary {
    background-color: var(--primary-color) !important;
}

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

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

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

/* Progress Bars */
.progress {
    height: 8px;
    border-radius: var(--border-radius-sm);
    background-color: var(--light-color);
    overflow: hidden;
}

.progress-bar {
    background-color: var(--success-color);
    transition: width var(--transition-normal);
}

/* Loading Overlay */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(255, 255, 255, 0.9);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
}

.loading-spinner {
    text-align: center;
}

.loading-text {
    margin-top: var(--spacing-md);
    color: var(--secondary-color);
    font-weight: 500;
}

/* Skip to Content Link */
.skip-to-content {
    position: absolute;
    top: -40px;
    left: 6px;
    background: var(--primary-color);
    color: var(--white);
    padding: var(--spacing-sm) var(--spacing-md);
    text-decoration: none;
    border-radius: var(--border-radius-md);
    z-index: 10000;
    transition: top var(--transition-fast);
}

.skip-to-content:focus {
    top: 6px;
}

/* Accessibility */
.visually-hidden {
    position: absolute !important;
    width: 1px !important;
    height: 1px !important;
    padding: 0 !important;
    margin: -1px !important;
    overflow: hidden !important;
    clip: rect(0, 0, 0, 0) !important;
    white-space: nowrap !important;
    border: 0 !important;
}

.visually-hidden-focusable:focus {
    position: static !important;
    width: auto !important;
    height: auto !important;
    padding: inherit !important;
    margin: inherit !important;
    overflow: visible !important;
    clip: auto !important;
    white-space: inherit !important;
}

/* Focus Styles */
*:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* High Contrast Mode Support */
@media (prefers-contrast: high) {
    :root {
        --primary-color: #0000ff;
        --secondary-color: #000000;
        --dark-color: #000000;
    }
}

/* Reduced Motion Support */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Print Styles */
@media print {
    .no-print {
        display: none !important;
    }
    
    body {
        font-size: 12pt;
        line-height: 1.4;
    }
    
    h1, h2, h3, h4, h5, h6 {
        page-break-after: avoid;
    }
    
    .btn {
        border: 1px solid #000;
        background: transparent !important;
        color: #000 !important;
    }
}