.content-wrap {
    display: flex;
    margin-top:30px;
    justify-content: space-between;
    flex-wrap: nowrap;
}

#cover {
    display: block;
    width: 20%;
    margin-right: 20px;
}

#content {

}

@media (max-width: 768px) {
    .content-wrap {
        flex-wrap: wrap;
    }

    #cover {
        display: block;
        width: 100%;
    }

    #content {
        display: block;
        width: 100%;
        margin-top: 20px;
    }

}