.back-to-top {
    width: 56px;
    padding: 1rem;
    position: fixed;
    bottom: 1rem;
    right: 1rem;
    border-radius: 1rem;
    border: 0;
    background-color: rgba(0, 0, 0, .8);
    box-shadow: 0 0 10px 2px rgba(0,0,0,.1);
}

.back-to-top svg {
    width: 1.2rem;
    height: 1.2rem;
}