.leaf {
    position: fixed;
    top: -50px;
    z-index: 9999;
    pointer-events: none;
    animation: fall linear forwards;
}

@keyframes fall {
    0% {
        transform: translateX(0) rotate(0deg);
        opacity: 1;
    }
    100% {
        transform: translateX(var(--x-move, 100px)) translateY(100vh) rotate(360deg);
        opacity: 0;
    }
}