.glass {
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
}

.spa-view {
    transition: opacity 0.25s ease-in-out;
}

/* Efeito de perspectiva para capas 3D dos e-books */
.book-container {
    perspective: 1000px;
}

.book-cover-3d {
    transform: rotateY(-15deg) rotateX(5deg);
    box-shadow: 10px 10px 20px rgba(0,0,0,0.2), -2px 0 5px rgba(255,255,255,0.4) inset;
    transition: transform 0.5s ease;
}

.book-container:hover .book-cover-3d {
    transform: rotateY(-5deg) rotateX(2deg);
}

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

.animate-fadeIn {
    animation: fadeIn 0.3s ease-out;
}