:root {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root #pcImg {
    width: 100%;
}

:root #pcImg img {
    width: 100%
}

:root #mobileImg {
    width: 100%;
    display: none;
}

:root #mobileImg img {
    width: 100%
}

@media screen and (max-width: 425px) {
    :root #pcImg {
        display: none;
    }

    :root #mobileImg {
        display: block;
    }
}