.boucing-ball {
    width: 100%;
    display: flex;   
    position: relative;
    animation: bounce 1.1s infinite;
    justify-content: center;
}

.boucing-ball img {
    width: 200px;
    height: 200px;
}

@keyframes bounce {
    0% {
        top: 350px;
    }

    50% {
        top: 200px;
        animation-timing-function: ease-in;
    }

    100% {
        top: 350px;
        animation-timing-function: ease-out;
    }
}