@media only screen and (max-width: 768px) {
  .video-modal-close {
    position: fixed;
    top: 16px;
    right: 16px;
    z-index: 99999;
    font-size: 28px;
    background: rgba(0,0,0,0.5);
    color: white;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    text-align: center;
    line-height: 40px;
    font-weight: bold;
    cursor: pointer;
  }
}