.containerPrincipal {
    background-color: #f7f7f7;
    border: 1px solid lightgray;
    box-shadow: 3px 3px 5px #888888;
    left: 155px;
    position: absolute; 
    width: 300px; 
    padding: 15px; 
    display: none; 
    z-index: 1;
}

@media only screen and (max-width: 959px) {
}

/*Tablet (Portrait)*/
@media only screen and (min-width: 768px) and (max-width: 959px) {
}

/*Tablet (landscape)*/
@media only screen and (max-width: 767px) {
}

/*Mobile (Landscape)*/
@media only screen and (min-width: 480px) and (max-width: 767px) {
    .containerPrincipal {
        position: relative;
        left: 0;
        width: 93%;
        float: left;
    }
}
            
/*Mobile (Portrait)*/
@media only screen and (max-width: 479px) {
    .containerPrincipal {
        position: relative;
        left: 0;
        width: 93%;
        float: left;
    }
}