body {
    margin: 0;
    padding: 20px;
}
.bille {
    width: 30px;
    height: 30px;
    position: absolute;
    top: 200px;
    left: 200px;
    background: radial-gradient(ellipse at center, rgba(181, 189, 200, 1) 0%, rgba(130, 140, 149, 1) 36%, rgba(40, 52, 59, 1) 100%);
    border-radius: 50%;
}