.responsive-virtual-preschool-iframe-container {

    position: relative;
    width: 100%;
    padding-bottom: 56.25%; /* 16:9 aspect ratio */
    height: 0;
    overflow: hidden;
}

.responsive-virtual-preschool-iframe-container iframe {

    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border: 0;
}