img {
    display: block;
    margin-left: auto;
    margin-right: auto;
    padding-top: 2vh;
    padding-bottom: 2vh;
    width: 50%;
}

iframe {
    display: block;
    margin-left: auto;
    margin-right: auto;
    width: 50%;
    margin-top: 2vh;
    margin-bottom: 2vh;
}