Trying to make this fit the entiref width

 <div class="nav_container"> 

<nav>
<ul class="fancyNav">

 <li id="home"><a href="http://www.worldclassads.com/index.php" class="homeIcon">Home</a></li>
 <li id="about"><a href="http://www.worldclassads.com/index.php?page=index/about">About us</a></li> 
 <li id="contact"><a href="http://www.worldclassads.com/index.php?page=user/support">Contact us</a></li>
 <li id="faqs"><a href="http://www.worldclassads.com/index.php?page=index/faqs">FAQ's</a>
 <li id="linktous"><a href="http://www.worldclassads.com/index.php?page=index/linktous">Link To Us</a></li>
 <li id="advertise"><a href="http://www.worldclassads.com/index.php?page=index/advertise">Advertise With Us</a>
 <li id="test"><a href="http://www.worldclassads.com/index.php?page=index/postad">Post an Ad</a>
 </li>
 
                
 </ul>
 </nav>
 </div>

/*----------------------------
    CSS3 Animated Navigation
-----------------------------*/


.fancyNav{
    /* Affects the UL element */
    overflow: hidden;
    display: inline-block;
}

.fancyNav li{
    /* Specifying a fallback color and we define CSS3 gradients for the major browsers: */
    
    background-color: #f0f0f0;
    background-image: -webkit-gradient(linear,left top, left bottom,from(#fefefe), color-stop(0.5,#f0f0f0), color-stop(0.51, #e6e6e6));
    background-image: -moz-linear-gradient(#fefefe 0%, #f0f0f0 50%, #e6e6e6 51%);
    background-image: -o-linear-gradient(#fefefe 0%, #f0f0f0 50%, #e6e6e6 51%);
    background-image: -ms-linear-gradient(#fefefe 0%, #f0f0f0 50%, #e6e6e6 51%);
    background-image: linear-gradient(#fefefe 0%, #f0f0f0 50%, #e6e6e6 51%);
    
    border-right: 1px solid rgba(9, 9, 9, 0.125);
    
    /* Adding a 1px inset highlight for a more polished efect: */
    
    box-shadow: 1px -1px 0 rgba(255, 255, 255, 0.6) inset;
    -moz-box-shadow: 1px -1px 0 rgba(255, 255, 255, 0.6) inset;
    -webkit-box-shadow: 1px -1px 0 rgba(255, 255, 255, 0.6) inset;
    
    position:relative;
    
    float: left;
    list-style: none;
}

.fancyNav li:after{

    /* This creates a pseudo element inslide each LI */    
    
    content:'.';
    text-indent:-9999px;
    overflow:hidden;
    position:absolute;
    width:100%;
    height:100%;
    top:0;
    left:0;
    z-index:1;
    opacity:0;
    
    /* Gradients! */
    
    background-image:-webkit-gradient(linear, left top, right top, from(rgba(168,168,168,0.5)),color-stop(0.5,rgba(168,168,168,0)), to(rgba(168,168,168,0.5)));
    background-image:-moz-linear-gradient(left, rgba(168,168,168,0.5), rgba(168,168,168,0) 50%, rgba(168,168,168,0.5));
    background-image:-o-linear-gradient(left, rgba(168,168,168,0.5), rgba(168,168,168,0) 50%, rgba(168,168,168,0.5));
    background-image:-ms-linear-gradient(left, rgba(168,168,168,0.5), rgba(168,168,168,0) 50%, rgba(168,168,168,0.5));
    background-image:linear-gradient(left, rgba(168,168,168,0.5), rgba(168,168,168,0) 50%, rgba(168,168,168,0.5));
    
    /* Creating borders with box-shadow. Useful, as they don't affect the size of the element. */
    
    box-shadow:-1px 0 0 #a3a3a3,-2px 0 0 #fff,1px 0 0 #a3a3a3,2px 0 0 #fff;
    -moz-box-shadow:-1px 0 0 #a3a3a3,-2px 0 0 #fff,1px 0 0 #a3a3a3,2px 0 0 #fff;
    -webkit-box-shadow:-1px 0 0 #a3a3a3,-2px 0 0 #fff,1px 0 0 #a3a3a3,2px 0 0 #fff;
    
    /* This will create a smooth transition for the opacity property */
    
    -moz-transition:0.25s all;
    -webkit-transition:0.25s all;
    -o-transition:0.25s all;
    transition:0.25s all;
}

/* Treating the first LI and li:after elements separately */

.fancyNav li:first-child{
    border-radius: 4px 0 0 4px;
}

.fancyNav li:first-child:after,
.fancyNav li.selected:first-child:after{
    box-shadow:1px 0 0 #a3a3a3,2px 0 0 #fff;
    -moz-box-shadow:1px 0 0 #a3a3a3,2px 0 0 #fff;
    -webkit-box-shadow:1px 0 0 #a3a3a3,2px 0 0 #fff;
    
    border-radius:4px 0 0 4px;
}

.fancyNav li:last-child{
    border-radius: 0 4px 4px 0;
}

/* Treating the last LI and li:after elements separately */

.fancyNav li:last-child:after,
.fancyNav li.selected:last-child:after{
    box-shadow:-1px 0 0 #a3a3a3,-2px 0 0 #fff;
    -moz-box-shadow:-1px 0 0 #a3a3a3,-2px 0 0 #fff;
    -webkit-box-shadow:-1px 0 0 #a3a3a3,-2px 0 0 #fff;
    
    border-radius:0 4px 4px 0;
}

.fancyNav li:hover:after,
.fancyNav li.selected:after,
.fancyNav li:target:after{
    /* This property triggers the CSS3 transition */
    opacity:1;
}

.fancyNav:hover li.selected:after,
.fancyNav:hover li:target:after{
    /* Hides the targeted li when we are hovering on the UL */
    opacity:0;
}

.fancyNav li.selected:hover:after,
.fancyNav li:target:hover:after{
    opacity:1 !important;
}

/* Styling the anchor elements */

.fancyNav li a{
    color: #5d5d5d;
    display: inline-block;
    font: 20px/1 Lobster,Arial,sans-serif;
    padding: 12px 35px 14px;
    position: relative;
    text-shadow: 1px 1px 0 rgba(255, 255, 255, 0.6);
    z-index:2;
    text-decoration:none !important;
    white-space:nowrap;
}

.fancyNav a.homeIcon{
    background:url('../navbar/img/home.png') no-repeat center center;
    display: block;
    overflow: hidden;
    padding-left: 12px;
    padding-right: 12px;
    text-indent: -9999px;
    width: 16px;
}


/*-------------------------
    Demo Page Styles
--------------------------*/


h1,h2{
    color: #fff;
    line-height: 1;
    background-color: #222;
    font-family: 'Segoe UI Light','Segoe UI',Arial,sans-serif;
    font-weight: normal;
    margin: 0 auto;
    position: absolute;
    left: 50%;
    margin-left: -446px;
}

h1{
    font-size: 36px;
    padding: 5px 15px 10px;
    top: 0;
}

h2{
    font-size: 14px;
    padding: 4px 13px 9px 11px;
    top: 51px;
}

header{
    display:block;
    margin-top:50px;
    position:relative;
}

.nav_container {background-color:#f5f5f5; background-image: url('../../images/textures/brushed-alum-dark.png'); border-bottom: 2px solid #000; float: left; width: 100%;}

nav{
    display: block;
    float: left;
    margin: 0 auto 0;
    text-align: center;
    width:     auto;
}

footer{
    color: #BBBBBB;
    font-size: 15px;
    line-height: 1.6;
    padding: 60px 20px 0;
    text-align: center;
    display:block;
}

footer b{
    color: #888888;
    display: block;
    font-size: 10px;
    font-weight: normal;
}

a, a:visited {
    text-decoration:none;
    outline:none;
    color:#54a6de;
}

a:hover{
    text-decoration:underline;
}