.up {
    width: 3rem;
    height: 3rem;
    background-color: #E21617;
    border-radius: 50%;
    padding: 2rem;
    position: fixed;
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    bottom: 2rem;
    right: 2rem;
    z-index: 99;
    transition: .3s ease-in-out;
}

.up.invisible {
    transform: scale(0);
}

.up__image {
    width: 2rem;
    transform: rotate(-90deg);
}

@media (min-width: 480px) {
    .up {
        width: 5rem;
        height: 5rem;
        bottom: 4rem;
        right: 4rem;
    }

    .up__image {
        width: 3rem;
    }
}

@media (min-width: 1025px) {
    .up {
        bottom: 6rem;
        right: 6rem;
    }

    .up:hover {
        background-color: #B81111;
        transform: scale(.95);
    }
}