.topo {
    background: #ffff;
    position: fixed;
    bottom: 20px;
    right: -500px;
    height: 50px;
    width: 50px;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    transition: .4s all;
}

.show-button .topo {
    right: 20px;
    transition: .4s all;
}

#suave img {
    width: 40px;
    height: 40px;
}