html, body {
    margin: 0;
    padding: 0;
    height: 100%;
}

div, iframe {
    margin: 0;
    padding: 0;
    border: 0;
}

.five9_adapter_wrapper {
    position: absolute;
    top: 0;
    bottom: 0;
    width: 100%;
}

.five9_adapter_wrapper iframe {
    position: absolute;
    width: 100%;
    height: 100%;
}