.gc-wrap {
    max-width: 800px;
    margin: 3% auto;
}
 
.g-calendar {
    position: relative;
    overflow: hidden;
    height: 0;
    padding-bottom: 70%;
}
 
.g-calendar iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}
 
@media screen and (max-width:767px) {
 
    .g-calendar {
        padding-bottom: 90%;
    }
 
}