* {
    padding: 0;
    margin: 0;
    box-sizing: border-box;
}
a {
    outline: none;
    color: inherit;
    text-decoration: none;
    transition: all .3s;
}

.content {
    width: 100%;
    height: 100vh;
}
.footer {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    line-height: 50px;
    display: flex;
    justify-content: center;
    font-size: 12px;
}

@media (max-width: 768px) {
    .image {
        width: 100%;
        height: 100%;
        background-image: url("../img/mobile.jpg");
        background-size: cover;
        background-position: center center;
        background-repeat: no-repeat;
        background-attachment: fixed;
        overflow: hidden;
    }
}

@media (min-width: 768px) {
    .image {
        width: 100%;
        height: 100%;
        background-image: url("../img/pc.jpg");
        background-size: cover;
        background-position: center center;
        background-repeat: no-repeat;
        background-attachment: fixed;
        overflow: hidden;
    }
}