/* ============================================
   Modern Educational Platform UX Redesign
   Clean, Intuitive, Student-Focused Design
   ============================================ */

:root {
    /* Modern Color Palette */
    --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --accent-gradient: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --success-gradient: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    --warning-gradient: linear-gradient(135deg, #fa709a 0%, #fee140 100%);
    
    /* Neutral Colors */
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --bg-dark: #0f172a;
    --bg-card: #ffffff;
    
    /* Text Colors */
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-muted: #94a3b8;
    --text-light: #cbd5e1;
    --text-white: #ffffff;
    
    /* Border & Shadows */
    --border-light: #e2e8f0;
    --border-medium: #cbd5e1;
    --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);
    
    /* Spacing */
    --space-xs: 0.5rem;
    --space-sm: 0.75rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    
    /* Border Radius */
    --radius-sm: 0.5rem;
    --radius-md: 0.75rem;
    --radius-lg: 1rem;
    --radius-xl: 1.5rem;
    --radius-full: 9999px;
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
    --transition-slow: 350ms ease;
}

/* Modern Container */
.modern-container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 var(--space-lg);
}

@media (max-width: 768px) {
    .modern-container {
        padding: 0 var(--space-md);
    }
}

/* Modern Card Design */
.modern-card {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-light);
    transition: all var(--transition-base);
}

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

.modern-card-compact {
    padding: var(--space-lg);
}

/* Modern Button Styles */
.modern-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
    padding: var(--space-sm) var(--space-lg);
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 0.95rem;
    transition: all var(--transition-base);
    cursor: pointer;
    border: none;
    text-decoration: none;
}

.modern-btn-primary {
    background: var(--primary-gradient);
    color: var(--text-white);
    box-shadow: var(--shadow-md);
}

.modern-btn-primary:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-1px);
}

.modern-btn-secondary {
    background: var(--bg-secondary);
    color: var(--text-primary);
    border: 1px solid var(--border-medium);
}

.modern-btn-secondary:hover {
    background: var(--bg-tertiary);
}

/* Modern Section Header */
.modern-section-header {
    margin-bottom: var(--space-2xl);
    text-align: center;
}

.modern-section-title {
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--text-primary);
    margin-bottom: var(--space-sm);
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.modern-section-subtitle {
    font-size: 1.125rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

@media (max-width: 768px) {
    .modern-section-title {
        font-size: 2rem;
    }
    .modern-section-subtitle {
        font-size: 1rem;
    }
}

/* Modern Grid Layouts */
.modern-grid {
    display: grid;
    gap: var(--space-lg);
}

.modern-grid-2 {
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

.modern-grid-3 {
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

.modern-grid-4 {
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
}

@media (max-width: 768px) {
    .modern-grid-2,
    .modern-grid-3,
    .modern-grid-4 {
        grid-template-columns: 1fr;
    }
}

/* Modern Progress Indicator */
.modern-progress-container {
    background: var(--bg-secondary);
    border-radius: var(--radius-xl);
    padding: var(--space-xl);
    margin-bottom: var(--space-xl);
}

.modern-progress-bar {
    width: 100%;
    height: 12px;
    background: var(--border-light);
    border-radius: var(--radius-full);
    overflow: hidden;
    margin-top: var(--space-md);
}

.modern-progress-fill {
    height: 100%;
    background: var(--primary-gradient);
    border-radius: var(--radius-full);
    transition: width 0.6s ease;
    position: relative;
}

.modern-progress-fill::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.3), transparent);
    animation: shimmer 2s infinite;
}

@keyframes shimmer {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(100%); }
}

/* Modern Stat Cards */
.modern-stat-card {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    text-align: center;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-light);
    transition: all var(--transition-base);
}

.modern-stat-card:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-4px);
}

.modern-stat-value {
    font-size: 2.5rem;
    font-weight: 800;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--space-xs);
}

.modern-stat-label {
    font-size: 0.95rem;
    color: var(--text-secondary);
    font-weight: 600;
}

/* Modern Badge */
.modern-badge {
    display: inline-flex;
    align-items: center;
    gap: var(--space-xs);
    padding: var(--space-xs) var(--space-md);
    border-radius: var(--radius-full);
    font-size: 0.875rem;
    font-weight: 600;
    background: var(--bg-secondary);
    color: var(--text-primary);
}

.modern-badge-primary {
    background: var(--primary-gradient);
    color: var(--text-white);
}

.modern-badge-success {
    background: var(--success-gradient);
    color: var(--text-white);
}

/* Modern Empty State */
.modern-empty-state {
    text-align: center;
    padding: var(--space-2xl);
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    border: 2px dashed var(--border-medium);
}

.modern-empty-state-icon {
    font-size: 4rem;
    color: var(--text-muted);
    margin-bottom: var(--space-lg);
}

.modern-empty-state-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--space-sm);
}

.modern-empty-state-text {
    color: var(--text-secondary);
    font-size: 1rem;
}

/* Modern Tab Navigation */
.modern-tabs {
    display: flex;
    gap: var(--space-sm);
    margin-bottom: var(--space-xl);
    flex-wrap: wrap;
}

.modern-tab {
    padding: var(--space-sm) var(--space-lg);
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 0.95rem;
    cursor: pointer;
    transition: all var(--transition-base);
    border: 2px solid transparent;
    background: var(--bg-secondary);
    color: var(--text-secondary);
}

.modern-tab:hover {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

.modern-tab-active {
    background: var(--primary-gradient);
    color: var(--text-white);
    box-shadow: var(--shadow-md);
    border-color: transparent;
}

/* Modern Content Card */
.modern-content-card {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-light);
    transition: all var(--transition-base);
    cursor: pointer;
}

.modern-content-card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-4px);
    border-color: var(--border-medium);
}

.modern-content-card-image {
    width: 100%;
    height: 200px;
    object-fit: cover;
    background: var(--primary-gradient);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-white);
    font-size: 3rem;
}

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

.modern-content-card-title {
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--space-sm);
}

.modern-content-card-meta {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-top: var(--space-md);
    padding-top: var(--space-md);
    border-top: 1px solid var(--border-light);
}

/* Modern Spacing Utilities */
.modern-mt-sm { margin-top: var(--space-sm); }
.modern-mt-md { margin-top: var(--space-md); }
.modern-mt-lg { margin-top: var(--space-lg); }
.modern-mt-xl { margin-top: var(--space-xl); }

.modern-mb-sm { margin-bottom: var(--space-sm); }
.modern-mb-md { margin-bottom: var(--space-md); }
.modern-mb-lg { margin-bottom: var(--space-lg); }
.modern-mb-xl { margin-bottom: var(--space-xl); }

.modern-p-sm { padding: var(--space-sm); }
.modern-p-md { padding: var(--space-md); }
.modern-p-lg { padding: var(--space-lg); }
.modern-p-xl { padding: var(--space-xl); }

/* Modern Glassmorphism Effect */
.modern-glass {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
}

/* Modern Loading State */
.modern-loading {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--space-2xl);
}

.modern-spinner {
    width: 40px;
    height: 40px;
    border: 4px solid var(--border-light);
    border-top-color: var(--primary-gradient);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

/* Modern Responsive Utilities */
@media (max-width: 768px) {
    .modern-hide-mobile {
        display: none !important;
    }
}

@media (min-width: 769px) {
    .modern-hide-desktop {
        display: none !important;
    }
}

/* Modern Focus States */
.modern-focus:focus {
    outline: 2px solid var(--primary-gradient);
    outline-offset: 2px;
}

/* Modern Animation Utilities */
.modern-fade-in {
    animation: fadeIn 0.5s ease-in;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.modern-slide-up {
    animation: slideUp 0.5s ease-out;
}

@keyframes slideUp {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}