iframe{
	border:0
}
* {
    box-sizing: border-box;
}
div.gallery iframe{
    width: 100%;
    height:300px;
}
.responsive {
    padding: 0 0 0 0;
    margin-bottom:10px;
    float: left;
    width: 50%;
}

@media only screen and (max-width: 800px) {
    .responsive {
        width: 100%;
        margin: 6px 0;
    }
    div.gallery iframe {
        max-height:300px;
    }
}