@media screen and (max-width: 500px) {
    button#play, button#pause {
        position: absolute;
        right: 10px;
        bottom: 10px;
        z-index: 9;
        text-align: center;
        padding: 0px 9px;
        width: 45px;
        height: 45px;
        display: block;
    }
    
}