Menù a tendina in primo piano.

[Edo1993]

Ciao a tutti,
Sto cercando di mettere in primo piano il menù a tendina. Se cliccate su "Distribuzione", la sezione sottostante viene coperta dalla slide.
Come posso fare?

LINK: http://www.christinaaguileraitalia.it/design/

Codice HTML:

<nav id="cbp-hrmenu" class="cbp-hrmenu">
                    <ul>
                        <li>
                            <a href="#">Prima Pagina</a>
                        </li>
                        <li>
                            <a href="#">Distribuzione</a>
                            <div class="cbp-hrsub">
                                <div class="cbp-hrsub-inner">
                                    <div>
                                        <ul> <h4>Servizi</h4>
                                            <li><a href="#">Volantinaggi / Consegne</a></li>
                                            <li><a href="#">Affissione Locandine</a></li>
                                            <li><a href="#">Camion Itineranti</a></li>
                                        </ul>
                                    </div>
                                    <div>
                                        <ul> <h4>Normative</h4>
                                            <li><a href="#">Normativa in materia di affissione</a></li>
                                            <li><a href="#">Normativa in materia di pubblicità</a></li>
                                        </ul>
                                    </div>                                </div><!-- /cbp-hrsub-inner -->
                            </div><!-- /cbp-hrsub -->
                        </li>
                        <li>
                            <a href="#">Grafica</a>
                        </li>
                                                <li>
                            <a href="#">Stampa</a>
                        </li>
                        <li>
                            <a href="#">Vieni A Teatro!</a>
                           
                        </li>
                        <li>
                            <a href="#">Organizzazione Eventi</a>
                        </li>
                    </ul>
                </nav>

Codice del CSS:

.cbp-hrmenu {
    width: 100%;
    margin-top: 2em;
    background-color: #005b9a;
    z-index:1;
}

/* general ul style */
.cbp-hrmenu ul {
    margin: 0;
    padding: 0;
    list-style-type: none;
}

/* first level ul style */
.cbp-hrmenu > ul,
.cbp-hrmenu .cbp-hrsub-inner {
    width: 90%;
    max-width: 70em;
    margin: 0 auto;
    padding: 0 1.875em;
        z-index:1;
}

.cbp-hrmenu > ul > li {
    display: inline-block;
}

.cbp-hrmenu > ul > li > a {
    font-weight: 500;
    padding: 1em 2em;
    color: #fff;
    text-transform:uppercase;
    display: inline-block;
}

.cbp-hrmenu > ul > li > a:hover {
    color: #ffdf01;
}

.cbp-hrmenu > ul > li.cbp-hropen a,
.cbp-hrmenu > ul > li.cbp-hropen > a:hover {
    color: #fff;
    background: #005490;
}

/* sub-menu */
.cbp-hrmenu .cbp-hrsub {
    display: none;
    position: absolute;
    background: #005490;
    width: 100%;
        z-index:1;
    left: 0;
}

.cbp-hropen .cbp-hrsub {
    display: block;
    padding-bottom: 3em;
}

.cbp-hrmenu .cbp-hrsub-inner > div {
    width: 33%;
    float: left;
    padding: 0 2em 0;
}

.cbp-hrmenu .cbp-hrsub-inner:before,
.cbp-hrmenu .cbp-hrsub-inner:after {
    content: " ";
    display: table;
}

.cbp-hrmenu .cbp-hrsub-inner:after {
    clear: both;
}

.cbp-hrmenu .cbp-hrsub-inner > div a {
    line-height: 2em;
}

.cbp-hrsub h4 {
    color: #ffdf01;
    padding: 2em 0 0.6em;
    margin: 0;
    font-size: 160%;
    font-weight: 500;
}

/* Examples for media queries */

@media screen and (max-width: 52.75em) { 

    .cbp-hrmenu {
        font-size: 80%;
    }

}

@media screen and (max-width: 43em) { 

    .cbp-hrmenu {
        font-size: 120%;
        border: none;
    }

    .cbp-hrmenu > ul,
    .cbp-hrmenu .cbp-hrsub-inner {
        width: 100%;
        padding: 0;
    }

    .cbp-hrmenu .cbp-hrsub-inner {
        padding: 0 2em;
        font-size: 75%;
    }

    .cbp-hrmenu > ul > li {
        display: block;
        border-bottom: 4px solid #005b9a;
    }

    .cbp-hrmenu > ul > li > a { 
        display: block;
        padding: 1em 3em;
    }

    .cbp-hrmenu .cbp-hrsub { 
        position: relative;
    }

    .cbp-hrsub h4 {
        padding-top: 0.6em;
    }

}

@media screen and (max-width: 36em) { 
    .cbp-hrmenu .cbp-hrsub-inner > div {
        width: 100%;
        float: none;
        padding: 0 2em;
    }
}

Grazie mille a chiunque risponderà : )