#scroll-up {
    transition: all 0.3s ease;
    cursor: pointer;
    display: none;
    height: 52px;
    position: fixed;
    left: 20px;
    top: 50px;
    width: 52px;
    z-index: 1035;
    border-radius: 50%;
    background-color: #c1c1c1;
}
#scroll-up:after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 20px;
    height: 20px;
    transform: translate(-50%, -50%) rotate(-90deg);
    background-image: url(/img/scroll.svg);
    background-position: center;
    background-repeat: no-repeat;
}
#scroll-up:hover {
    background-color: #878585;
}

@media screen and (max-width: 480px) {
    #scroll-up {
        background-size: cover;
        height: 40px;
        width: 40px;
        left: 10px;
    }
}

@media screen and (max-width: 639px) {
    #scroll-up {
        top: auto;
        right: 20px;
        bottom: 20px;
    }
}