/* BackGround Transparent*/
.backImage:before {
    content: ' ';
    display: block;
    position: absolute;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    opacity: 0.05;
    background-image: url('http://concursos.cm-gaia.pt/cmgconcursos/assets/img/cmgaia_noite.png');
    background-repeat: no-repeat;
    background-position: 50% 0;
    -ms-background-size: cover;
    -o-background-size: cover;
    -moz-background-size: cover;
    -webkit-background-size: cover;
    background-size: cover;
}