.iframe-piwik {
    width: 100%;
    height: 255px;
    margin-left: -8px;
    border: 0;
}

@media only screen and (min-width: 576px) {
    .iframe-piwik {
        height: 172px;
    }
}

@media only screen and (min-width: 768px) {
    .iframe-piwik {
        height: 150px;
    }
}

@media only screen and (min-width: 992px) {
    .iframe-piwik {
        height: 120px;
    }
}

@media only screen and (min-width: 1200px) {
    .iframe-piwik {
        height: 100px;
    }
}