.mvt-dfp-center {
    width:300px;
    height:250px;
    float:none;
    margin:0 auto;
}
.mvt-dfp-left {
    width:300px;
    height:250px;
    float:left;
    margin:0.4em 1em 0.2em 0;
}
.mvt-dfp-right {
    width:300px;
    height:250px;
    float:right;
    margin:0.4em 0 0.2em 1em;
}
.mvt-brick {
    width:300px;
    height:100px;
    float:left;
    margin:0 1.3em 1.5em;
}

@media screen and (max-width: 767px) {
    [id^=div-gpt-ad] {
        float:none;
        margin:0 auto;
    }
}

@media screen and (max-width: 414px) {
    .mvt-dfp-left, .mvt-dfp-right {
        float:none;
        margin:1em auto;
    }
    .mvt-brick {
        float:none;
        margin:1em auto;
    }
}