#alerta-topo {
    position: fixed;
    top: 0px;
    left: 0px;
    width: 100%;
    height: 0px;
    overflow: visible;
    z-index: 99999;
}

#mensagem-alerta-topo {
    width: 90%;
    max-width: 500px;
    min-width: 250px;
    margin: 0 auto;
}

#alerta-topo .alert {
    -webkit-box-shadow: 0 6px 12px rgba(0,0,0,.175);
    -moz-box-shadow: 0 6px 12px rgba(0,0,0,.175);
    box-shadow: 0 6px 12px rgba(0,0,0,.175);
}

.alert.topo {
    border-top-left-radius: 0px;
    border-top-right-radius: 0px;
    font-size: 15px;
}