@media screen and (min-width:320px) and (max-width: 991px) {
    [class*="col-xs"] {
        width: 100%;
        margin-bottom: 20px;
    }
    .header .logo {
        display:block;
        width: 100%;
        text-align: center;
    }

    .navigation {
        display:inline-block;
        position: relative;
        float:none;
        margin-top: 20px;
        margin-left: -185px;
        left:50%;
    }

    .caption {
        text-align: center;
    }
    
    /* author */

    .nav-previous {
        float:left;
    }
    
    #author-info h3 {
        margin-bottom: 20px;
        text-align: center;
    }
    
    .author-display {
        text-align: center;
        display: block;
    }

    .author-display img {
        float:none;
    }

    #author-description {
        text-align: center;
        clear:both;
        float:none;
        margin-top: 20px;
        margin-left: 0px;
    }

}