Sebagai gambaranya bisa lihat demonya dibawah ini :
Untuk konsep dasarnya sebagai berikut :
CSS
@import url(http://netdna.bootstrapcdn.com/font-awesome/4.0.3/css/font-awesome.css);
#menu{
width: 100%;
padding:10px 0 0 0;
list-style: none;
background: #34495e;border-left:30px solid #34495e;border-radius:3px
}
#menu li{
float: left;
padding:0 0 10px 0;
position: relative;
}
#menu a{
float: left;
height: 25px;
padding:0 12px 0 12px;
color: #fff;
text-transform: uppercase;
font: bold 12px/25px Arial, Helvetica;
text-decoration: none;
}
#menu li:hover > a{background:#16a085;
color: #fff;
}
*html #menu li a:hover{ /* IE6 */
color: #fff;
}
#menu li:hover > ul{
display: block;
}
/* Sub-menu */
#menu ul{
list-style: none;
margin: 0;
padding: 0;
display: none;
position: absolute;
top: 35px;
left: 0;
z-index: 99999;
background: #2c3e50;
-moz-border-radius: 5px;
border-radius: 5px;
}
#menu ul li{
float: none;
margin:0;
padding: 0;
display: block;
}
#menu ul li:last-child{
}
#menu ul a{
padding: 10px;
height: auto;
line-height: 1;
display: block;
white-space: nowrap;
float: none;
text-transform: none;
}
*html #menu ul a{ /* IE6 */
height: 10px;
width: 150px;
}
*:first-child+html #menu ul a{ /* IE7 */
height: 10px;
width: 150px;
}
#menu ul a:hover{
background: #16a085;
}
#menu ul li:first-child a{
-moz-border-radius: 5px 5px 0 0;
-webkit-border-radius: 5px 5px 0 0;
border-radius: 5px 5px 0 0;
}
#menu ul li:first-child a:after{
content: '';
position: absolute;
left: 30px;
top: -8px;
width: 0;
height: 0;
border-left: 5px solid transparent;
border-right: 5px solid transparent;
border-bottom: 8px solid #2c3e50;
}
#menu ul li:first-child a:hover:after{
border-bottom-color: #2c3e50;
}
#menu ul li:last-child a{
-moz-border-radius: 0 0 5px 5px;
-webkit-border-radius: 0 0 5px 5px;
border-radius: 0 0 5px 5px;
}
/* Clear floated elements */
#menu:after{
visibility: hidden;
display: block;
font-size: 0;
content: " ";
clear: both;
height: 0;
}
#menu{
width: 100%;
padding:10px 0 0 0;
list-style: none;
background: #34495e;border-left:30px solid #34495e;border-radius:3px
}
#menu li{
float: left;
padding:0 0 10px 0;
position: relative;
}
#menu a{
float: left;
height: 25px;
padding:0 12px 0 12px;
color: #fff;
text-transform: uppercase;
font: bold 12px/25px Arial, Helvetica;
text-decoration: none;
}
#menu li:hover > a{background:#16a085;
color: #fff;
}
*html #menu li a:hover{ /* IE6 */
color: #fff;
}
#menu li:hover > ul{
display: block;
}
/* Sub-menu */
#menu ul{
list-style: none;
margin: 0;
padding: 0;
display: none;
position: absolute;
top: 35px;
left: 0;
z-index: 99999;
background: #2c3e50;
-moz-border-radius: 5px;
border-radius: 5px;
}
#menu ul li{
float: none;
margin:0;
padding: 0;
display: block;
}
#menu ul li:last-child{
}
#menu ul a{
padding: 10px;
height: auto;
line-height: 1;
display: block;
white-space: nowrap;
float: none;
text-transform: none;
}
*html #menu ul a{ /* IE6 */
height: 10px;
width: 150px;
}
*:first-child+html #menu ul a{ /* IE7 */
height: 10px;
width: 150px;
}
#menu ul a:hover{
background: #16a085;
}
#menu ul li:first-child a{
-moz-border-radius: 5px 5px 0 0;
-webkit-border-radius: 5px 5px 0 0;
border-radius: 5px 5px 0 0;
}
#menu ul li:first-child a:after{
content: '';
position: absolute;
left: 30px;
top: -8px;
width: 0;
height: 0;
border-left: 5px solid transparent;
border-right: 5px solid transparent;
border-bottom: 8px solid #2c3e50;
}
#menu ul li:first-child a:hover:after{
border-bottom-color: #2c3e50;
}
#menu ul li:last-child a{
-moz-border-radius: 0 0 5px 5px;
-webkit-border-radius: 0 0 5px 5px;
border-radius: 0 0 5px 5px;
}
/* Clear floated elements */
#menu:after{
visibility: hidden;
display: block;
font-size: 0;
content: " ";
clear: both;
height: 0;
}
HTML
<ul id="menu">
<li>
<a href="#"><i class="fa fa-cogs"></i> MENU 1</a>
<ul>
<li><a href='#'> <i class="fa fa-cogs"></i> Settings</a></li>
<li><a href='#'> <i class="fa fa-envelope-o"></i> Contact Me</a></li>
<li><a href='#'> <i class="fa fa-tag"></i> Tag</a></li>
<li><a href='#'> <i class="fa fa-user"></i> About Me</a></li>
</ul>
</li>
<li>
<ul>
menu seterusnya.....
</ul>
</li>
</ul>
<li>
<a href="#"><i class="fa fa-cogs"></i> MENU 1</a>
<ul>
<li><a href='#'> <i class="fa fa-cogs"></i> Settings</a></li>
<li><a href='#'> <i class="fa fa-envelope-o"></i> Contact Me</a></li>
<li><a href='#'> <i class="fa fa-tag"></i> Tag</a></li>
<li><a href='#'> <i class="fa fa-user"></i> About Me</a></li>
</ul>
</li>
<li>
<ul>
menu seterusnya.....
</ul>
</li>
</ul>
Anda cukup mengganti tanda # dengan url yang ingin anda masukkan, baca juga drop down menu metro ui awesome dan modern dropdown menu button css3