.portrait {
    float: left;
    padding: 10px;
    margin-right: 30px;
    border: solid #111 5px;
}

@media (max-width: 650px) {
    .portrait {
        float: none;
        min-width: 70%;
        padding: 10px;
        margin-left: auto;
        margin-right: auto;
    }
}