html, body {
    margin: 0;
    padding: 0;
}

.mframe_div {
    margin: 0 auto;
    padding: 0 12px;
    max-width: 1200px;
}

.mframe {
    display: block;
    width: 100%;
    height: 80vh;
    min-height: 520px;
    border: 0;
}