.book {
    position: absolute;
    width: 100px;
    height: 75px;
    background-image: url('./assets/bookBG.png');
    background-size: contain;
    background-repeat: no-repeat;
    z-index: 10;
    opacity: 0.8;
    pointer-events: none;
    animation-timing-function: linear;
    animation-iteration-count: infinite;
    will-change: transform;
}

.book1 {
    animation-name: fall1;
}

.book2 {
    animation-name: fall2;
}

.book3 {
    animation-name: fall3;
}

@keyframes fall1 {
    0% {
        transform: translateY(0) rotate(0deg) scale(var(--size));
    }
    100% {
        transform: translateY(calc(100vh + 200px)) rotate(360deg) scale(var(--size));
    }
}

@keyframes fall2 {
    0% {
        transform: translateY(0) rotate(45deg) scale(var(--size));
    }
    100% {
        transform: translateY(calc(100vh + 200px)) rotate(405deg) scale(var(--size));
    }
}

@keyframes fall3 {
    0% {
        transform: translateY(0) rotate(-30deg) scale(var(--size));
    }
    100% {
        transform: translateY(calc(100vh + 200px)) rotate(330deg) scale(var(--size));
    }
}