body{
    width: 100%;
    height: 1800px;
    background-image: url('renovando.jpg');
    background-size: 100%;
    background-repeat: no-repeat;
}

@media screen and (max-width: 600px) {
    body{
    background-image: url('renovando2.jpg');
    background-size: 100%;
    background-repeat: no-repeat;
    }
    
}