.cf-video-container {
    position: relative;
    width: 100%;
    padding-top: 56.25%; /* 16:9 */
    background: #fff;
    overflow: hidden;
    border-radius: 50px;
}

.cf-video-container iframe {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    border: 0;
    border-radius: 50px;
}