.float-button {
    position: fixed;
    width: 64px;
    height: 64px;
    bottom: 20px;
    right: 20px;
    z-index: 100;
    transition: transform .2s;
    filter: brightness(90%);
}

.float-button:hover {
    transform: scale(1.1);
    filter: brightness(100%);
}