#principal{
    margin-top: 14%;
    background-image: url(imagenes/fondo%20nosotros.jpg);
    background-position: top;
background-repeat: repeat-y;
background-attachment: inherit;
background-size: cover;
background-color: #464646;
border-color: #ffffff;
        border: solid ;
    border-width:thick;
    width: 60%;
    margin-left: 15%;
    float: none;
        padding-top: 24%;
    padding-left: 5%;
    padding-right: 5%;
    color: #ffffff;
    padding-bottom: 4em;
}
#principal p {
    text-align: justify;
    padding: 0 2em 1em;
    font-size: 1.2em;
}
body{
    background-image: url(fondo/piso%20de%20madera.jpg);
}
@media (max-width: 900px){
    #principal  {
        width: 90%;
        margin: 14% 5% 10% 5%;
        padding: 29% 0 0 0;
        
}
}