@media only screen and (max-width: 600px) {
#fotocapa{
    content: url(../images/capa.png);
    width: 100%;
    height: 100%;
}
body{
    border: 0;
    padding: 0;
    margin: 0;
}
}
@media only screen and (min-width: 601px) {
    #fotocapa{
        
        content: url(../images/pagina.png);
        width: 46%;
    }
    body{
        background-image: url(../images/bg.png);
        background-size: 100%;
        background-repeat: no-repeat;
        text-align: center;
        border: 0;
        padding: 0;
        margin: 0;
    }
}