html {
    scroll-behavior: smooth;
    scroll-padding-top: 80px;
}
.hero-gradient {
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 50%, #0f3460 100%);
}
.glass-effect {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
}
.video-card:hover .play-overlay {
    opacity: 1;
}
.locked-video {
    filter: grayscale(0.8);
    cursor: not-allowed;
}
.card-hover {
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}
.card-hover:hover {
    transform: translateY(-5px);
    box-shadow: 0 20px 25px -5px rgba(0,0,0,0.1);
}
.nivel-tab {
    transition: all 0.3s ease;
}
.nivel-tab.active {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    box-shadow: 0 10px 20px rgba(102, 126, 234, 0.3);
}
.loading-spinner {
    border: 3px solid #f3f3f3;
    border-top: 3px solid #667eea;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    animation: spin 1s linear infinite;
}
@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}
.line-clamp-1,
.line-clamp-2 {
    display: -webkit-box;
    -webkit-box-orient: vertical;
    overflow: hidden;
}
.line-clamp-1 { -webkit-line-clamp: 1; }
.line-clamp-2 { -webkit-line-clamp: 2; }

/* Estilos mejorados del explorador */
.rama-carpeta {
    margin-bottom: 0.5rem;
}
.contenido-rama {
    margin-top: 0.5rem;
    position: relative;
    border-left: 1px solid #e2e8f0;
}
.rama-carpeta .contenido-rama .rama-carpeta {
    margin-left: 0;
}