#content {

    display: flex;
    justify-content: center;
    flex-direction: row;
    flex-wrap: wrap;
}

@media (min-width: 850px) {
    #content {
        width: 80%;
    }

    .scroll-up {
        opacity: 0;
        visibility: hidden;
        transform: translateY(50px);
        transition: all 1s;
    }

    .scroll-up.is-show {
        opacity: 1;
        visibility: visible;
        transform: translateY(0px);
    }
}

@media (max-width: 849px) {
    body {
        display: flex;
        flex-direction: column;
        justify-content: stretch;
        align-items: center;
        font-family: 'Noto Sans JP', sans-serif;
    }


    .scroll-up {
        opacity: 1;
        visibility: visible;

    }

    .scroll-up.is-show {
        opacity: 1;
        visibility: visible;

    }
}