.veranstltung {
    overflow-x:hidden;
    overflow-y: auto;
    position: absolute; 
    top: 0; 
    left: 0; 
    right: 0; 
    bottom: 50px;

}

.ifframe {
    -webkit-overflow-scrolling: touch;
    width:100vw;
    height: calc(100vh - 51px);
    border: none;
    overflow-x:hidden;
    overflow-y: auto;
}