<a id="touch-menu" class="mobile-menu" href="#"><i class="icon-reorder"></i>Menu</a>
<nav>
<ul class="menu">
<li><a href="#"><i class="icon-home"></i>HOME</a>
<ul class="sub-menu">
<li><a href="#">Sub-Menu 1</a></li>
<li><a href="#">Sub-Menu 2</a></li>
<li><a href="#">Sub-Menu 3</a></li>
</ul>
</li>
<li><a href="#"><i class="icon-user"></i>ABOUT</a></li>
<li><a href="#"><i class="icon-camera"></i>PORTFOLIO</a>
<ul class="sub-menu">
<li><a href="#">Sub-Menu 1</a></li>
<li><a href="#">Level 3 Menu</a>
<ul>
<li><a href="#">Sub-Menu 4</a></li>
<li><a href="#">Sub-Menu 5</a></li>
<li><a href="#">Sub-Menu 6</a></li>
</ul>
</li>
</ul>
</li>
<li><a href="#"><i class="icon-bullhorn"></i>BLOG</a></li>
<li><a href="#"><i class="icon-envelope-alt"></i>CONTACT</a></li>
</ul>
</nav>

.menu{display:block;}
   
.menu li{display: inline-block;
position: relative;
z-index:100;}
   
.menu li a {font-weight:600;
text-decoration:none;
padding:11px;
display:block;
color:#ffffff;
   
-webkit-transition: all 0.2s ease-in-out 0s;
  -moz-transition: all 0.2s ease-in-out 0s;
  -o-transition: all 0.2s ease-in-out 0s;
  -ms-transition: all 0.2s ease-in-out 0s;
  transition: all 0.2s ease-in-out 0s;
}
   
.menu li a:hover, .menu li:hover > a{color:#ffffff;
background:#9CA3DA;}
/* hide the second level menu */
.menu ul {display: none;
margin: 0;
padding: 0;
width: 150px;
position: absolute;
top: 43px;
left: 0px;
background: #ffffff;
}
   
/* display second level menu on hover */
.menu li:hover > ul{ display: block;}
   
.menu ul li {display:block;
float: none;
background:none;
margin:0;
padding:0;
}
   
.menu ul li a {font-size:12px;
font-weight:normal;
display:block;
color:#797979;
border-left:3px solid #ffffff;
background:#ffffff;}
   
.menu ul li a:hover, .menu ul li:hover > a{
background:#f0f0f0;
border-left:3px solid #9CA3DA;
color:#797979;
}
/* change level 3 menu positions */
.menu ul ul {left: 149px;
  top: 0px;
}
.mobile-menu{display:none;
width:100%;
padding:11px;
background:#3E4156;
color:#ffffff;
text-transform:uppercase;
font-weight:600;
}
.mobile-menu:hover{background:#3E4156;
color:#ffffff;
text-decoration:none;
}

@media (max-width: 767px) {
   
.menu{display:none;}
   
.mobile-menu{display:block;
margin-top:100px;}
   
nav{margin:0;
background:none;}
   
.menu li{display:block;
margin:0;}
   
.menu li a {background:#ffffff;
color:#797979;
border-top:1px solid #e0e0e0;
border-left:3px solid #ffffff;}
   
.menu li a:hover, .menu li:hover > a{
background:#f0f0f0;
color:#797979;
border-left:3px solid #9CA3DA;}
   
/*level 2 and 3 - make same width as all items*/
.menu ul {display:block;
position:relative;
top:0;
left:0;
width:100%;}
   
.menu ul ul {left:0;}
   
}/*end media queries*/

<link href="http://netdna.bootstrapcdn.com/font-awesome/4.2.0/css/font-awesome.min.css" rel="stylesheet" type="text/css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js" type="text/javascript"></script>
<script type="text/javascript">
$(document).ready(function(){  
  var touch = $('#touch-menu');
  var menu = $('.menu');
   
  $(touch).on('click', function(e) {
  e.preventDefault();
  menu.slideToggle();
  });
   
  $(window).resize(function(){
  var w = $(window).width();
  if(w > 767 && menu.is(':hidden')) {
  menu.removeAttr('style');
  }
  });
   
});
</script>