.back-to-top{
    position:fixed;
    right:24px;
    bottom:24px;
    width:56px;
    height:56px;
    border:none;
    border-radius:50%;
    display:flex;
    align-items:center;
    justify-content:center;
    cursor:pointer;

    color:#fff;
    background:#1765d8;

    box-shadow:0 12px 35px rgba(0,0,0,.18);

    opacity:0;
    visibility:hidden;
    transform:translateY(20px);

    transition:
        opacity .25s,
        transform .25s,
        visibility .25s;

    z-index:9999;
}

.back-to-top svg{
    width:24px;
    height:24px;
}

.back-to-top.is-visible{
    opacity:1;
    visibility:visible;
    transform:none;
}

.back-to-top:hover{
    transform:translateY(-3px);
    background:#0a4fc5;
}

.back-to-top:focus-visible{
    outline:3px solid #fff;
    outline-offset:3px;
}

@media(max-width:768px){

    .back-to-top{

        right:16px;
        bottom:16px;

        width:50px;
        height:50px;

    }

}