#content_main{
    width: 440px;
}

#content_main.col-parent {
    width: 640px;
}

@media screen and (max-width: 1024px) {
    .content {
        max-width: 750px;
    }
}

@media screen and (max-width: 768px) {
    .content {
        max-width: 500px;
    }
}