.myDlgShadow{
  position: fixed; left:0; top:0; right:0; bottom:0;
  background: rgba(0,0,0,.55);
  z-index: 9998;
}

.myDlg{
  position: absolute; /* важно: центрирование через scrollTop */
  z-index: 9999;
  background:#fff;
  box-shadow: 0 10px 40px rgba(0,0,0,.35);
}

.myDlg__head{
  position: relative;
  padding: 18px 52px 18px 52px;
  text-align:center;
  font-weight:600;
}

.myDlg__close{
  position:absolute;
  right:14px; top:10px;
  font-size:28px;
  line-height:28px;
  cursor:pointer;
  user-select:none;
}

.myDlg__body{
  padding: 0 24px 24px 24px;
}

.myDlg__media{
  width:100%;
  height:100%;
}
.myDlg__media video{
  width:100%;
  height:100%;
  display:block;
  object-fit: contain;
}