Sombra em texto

Opa..

Estou fazendo um site, e gostaria q o texto do menu tivesse sombra e não estou conseguindo o resultado.

Alguem pode me ajudar?

O Css é:

#menu {padding-top:30px}
#menu > li {width:100%;overflow:hidden;padding-bottom:4px}
#menu > li > a {display:inline-block;font-size:26px;line-height:54px;height:56px;color:#fff;background:none;text-decoration:none;position:relative;letter-spacing:0px;cursor:pointer}
#menu > li > a span {display:block;background:#fff;position:absolute;width:100%;height:100%;top:0;left:0}
#menu > li > a strong {position:relative;display:block;padding:0 95px 0 40px;height:56px}
#menu > li > a:hover, #menu > li > a.active {color:#000}
#menu > li > a:hover strong, #menu > li > a.active strong{}

E o Html:

<ul id="menu">
<li><a href="#!/page_Home"><span></span><strong>Principal</strong></a></li>
 <li><a href="#!/page_About"><span></span><strong>O Grupo</strong></a></li>
<li><a href="#!/page_Portfolio"><span></span><strong>Apresentações</strong></a></li>
<li><a href="#!/page_Services"><span></span><strong>Imprensa</strong></a></li>
<li><a href="#!/page_Contact"><span></span><strong>Fale Conosco</strong></a></li>
</ul>