:root {
    --primary-color: #667eea;
    --secondary-color: #764ba2;
    --accent-color: #f093fb;
    --dark-color: #2c3e50;
    --light-color: #f8f9fa;
    --border-radius: 12px;
    --box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
}

body {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

/* Navigation */
.navbar {
    background: rgba(255, 255, 255, 0.1) !important;
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    padding: 1rem 0;
}

.navbar-brand {
    background: linear-gradient(45deg, #fff, #f093fb);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.nav-link {
    color: rgba(255, 255, 255, 0.9) !important;
    font-weight: 500;
    transition: var(--transition);
}

.nav-link:hover {
    color: var(--accent-color) !important;
    transform: translateY(-1px);
}

/* Main Content */
.main-content {
    padding-top: 2rem;
    padding-bottom: 2rem;
}

/* Hero Section */
.hero-section {
    color: white;
    padding: 4rem 0;
}

.hero-section h1 {
    background: linear-gradient(45deg, #fff, #f093fb);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
    font-size: 4rem;
    margin-bottom: 1.5rem;
}

.hero-section .lead {
    font-size: 1.3rem;
    opacity: 0.95;
    line-height: 1.6;
}

/* Feature Cards */
.features-grid {
    margin: 3rem 0;
}

.feature-card {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: var(--border-radius);
    padding: 2rem 1.5rem;
    text-align: center;
    color: white;
    transition: var(--transition);
    height: 100%;
}

.feature-card:hover {
    transform: translateY(-5px);
    background: rgba(255, 255, 255, 0.15);
}

.feature-icon {
    width: 48px;
    height: 48px;
    margin-bottom: 1rem;
    color: var(--accent-color);
}

.feature-card h5 {
    margin-bottom: 1rem;
    font-weight: 600;
}

.feature-card p {
    opacity: 0.9;
    margin-bottom: 0;
}

/* Buttons */
.btn-primary {
    background: linear-gradient(45deg, var(--primary-color), var(--secondary-color));
    border: none;
    border-radius: var(--border-radius);
    padding: 0.75rem 2rem;
    font-weight: 600;
    transition: var(--transition);
    box-shadow: var(--box-shadow);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.2);
    background: linear-gradient(45deg, var(--secondary-color), var(--primary-color));
}

.btn-lg {
    padding: 1rem 2.5rem;
    font-size: 1.1rem;
}

/* Dashboard */
.dashboard-header h2 {
    color: white;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.dashboard-header p {
    color: rgba(255, 255, 255, 0.8);
    font-size: 1.1rem;
}

/* Cards */
.card {
    border: none;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    transition: var(--transition);
}

.card:hover {
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.15);
}

.card-title {
    color: var(--dark-color);
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

/* Form Elements */
.form-select {
    border-radius: var(--border-radius);
    border: 2px solid #e9ecef;
    transition: var(--transition);
    font-size: 1rem;
}

.form-select:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 0.2rem rgba(102, 126, 234, 0.25);
}

/* Video Cards */
.video-card {
    background: white;
    border-radius: var(--border-radius);
    overflow: hidden;
    transition: var(--transition);
    border: 2px solid transparent;
    height: 100%;
}

.video-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--box-shadow);
    border-color: var(--primary-color);
}

.video-thumbnail {
    position: relative;
    overflow: hidden;
    border-radius: var(--border-radius) var(--border-radius) 0 0;
    aspect-ratio: 16/9;
}

.video-thumbnail img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition);
}

.video-overlay {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: rgba(0, 0, 0, 0.7);
    border-radius: 50%;
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: var(--transition);
}

.video-card:hover .video-overlay {
    opacity: 1;
}

.play-icon {
    color: white;
    width: 20px;
    height: 20px;
}

.video-info {
    padding: 1rem;
}

.video-title {
    font-size: 0.9rem;
    font-weight: 600;
    line-height: 1.3;
    margin-bottom: 0.5rem;
    color: var(--dark-color);
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

/* Checkboxes */
.form-check-input {
    width: 1.2rem;
    height: 1.2rem;
    border-radius: 4px;
    border: 2px solid #dee2e6;
    transition: var(--transition);
}

.form-check-input:checked {
    background-color: var(--primary-color);
    border-color: var(--primary-color);
}

.form-check-input:focus {
    box-shadow: 0 0 0 0.2rem rgba(102, 126, 234, 0.25);
}

.form-check-label {
    cursor: pointer;
    transition: var(--transition);
}

/* Alerts */
.alert {
    border: none;
    border-radius: var(--border-radius);
    font-weight: 500;
    box-shadow: var(--box-shadow);
}

.alert-success {
    background: linear-gradient(45deg, #28a745, #20c997);
    color: white;
}

.alert-danger {
    background: linear-gradient(45deg, #dc3545, #e83e8c);
    color: white;
}

.alert-info {
    background: linear-gradient(45deg, #17a2b8, #6f42c1);
    color: white;
}

/* Loading States */
.spinner-border {
    width: 3rem;
    height: 3rem;
}

/* Modal */
.modal-content {
    border: none;
    border-radius: var(--border-radius);
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
}

/* Responsive Design */
@media (max-width: 768px) {
    .hero-section h1 {
        font-size: 2.5rem;
    }
    
    .hero-section .lead {
        font-size: 1.1rem;
    }
    
    .feature-card {
        margin-bottom: 1rem;
    }
    
    .btn-lg {
        padding: 0.875rem 2rem;
        font-size: 1rem;
    }
    
    .video-card {
        margin-bottom: 1rem;
    }
}

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

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

.slide-up {
    animation: slideUp 0.3s ease-out;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Utility Classes */
.text-gradient {
    background: linear-gradient(45deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.glass-effect {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
}