aqui les dejo el css
Código:
  
y este es el menunav {
	width: auto;
	z-index: 9999;
	text-align: center;
	background: -moz-linear-gradient(#fc6b6b , #ed0606);
	background: -webkit-linear-gradient(#fc6b6b , #ed0606);
}
nav ul {
	list-style: none;
	padding: 0;
	margin: 0;
}
nav ul ul {
	display:none;
	position: absolute;
	padding: 0;
}
nav ul ul ul {
	margin-left: 194px;
	margin-top: -30px;
}
nav li:hover > ul {
	display:block;
}
nav li{
 	display:inline-block;
	list-style-type:none;
	padding:10px 0px;
	margin:0;
	z-index:9999;
	position:relative;
}
nav li.submenu{
 	display:inline-block;
	list-style-type:none;
	padding:0;
	margin:0;
	z-index:9999;
}
nav li.subsubmenu{
 	display:inline-block;
	list-style-type:none;
	width: 100px;
	padding:0;
	margin:0;
	z-index:9999;
}
nav li.nav{
	margin-left: -5px;
	background: -moz-linear-gradient(#fc6b6b , #ed0606);
	background: -webkit-linear-gradient(#fc6b6b , #ed0606);
	z-index:9999;
}
nav li a {
	color:#FFFFFF;
	text-decoration:none;
	display:block;
	width: 95px;
	padding-top:5px;
	padding-bottom: 5px;
	text-align:center;
	z-index:9999;
}
nav ul.submenu {
	background: #ed0606;
	width: 194px;
	height: 150px;
	z-index:9990;
	margin-top: 10px;
	background-color: rgba(0, 0, 0, 0.7);
	display: none;
}
nav ul.subsubmenu {
	width: 100px;
	z-index:9999;
	background-color: rgba(0, 0, 0, 0.7);
	display: none;
}
nav li.nav a:hover{
	z-index: 9999;
	background: -moz-linear-gradient(#fd8d8d , #ea3333);
	background: -webkit-linear-gradient(#fd8d8d , #ea3333);
}
nav li.submenu a:hover{
	background: -moz-radial-gradient(50% , #ee0909 , transparent);
	background: -webkit-radial-gradient(50% , #ee0909 , transparent);
	z-index:9990;
}
nav li li a{
   width:194px;
   display:block;
   z-index:9999;
}
nav li li.subsubmenu a{
   width:100px;
   display:block;
   z-index:9999;
}
nav li ul {
   width: 100px;	
   height: auto;
   border-bottom-left-radius: 10px;   
   border-bottom-right-radius: 10px;
   z-index:9999;
   position: absolute;
}
Código HTML:
 <nav> <ul class="nav"> <li class="nav"><a href="#">menu 1</a></li> <li class="nav"><a href="#">menu 2</a></li> <li class="nav"><a href="#">menu 3</a> <ul class="submenu"> <li class="submenu"><a href="#">menu 3.1</a> <ul class="subsubmenu"> <li class="subsubmenu"><a href="#">menu 3.1.1</a></li> <li class="subsubmenu"><a href="#">menu 3.1.2</a></li> <li class="subsubmenu"><a href="#">menu 3.1.3</a></li> <li class="subsubmenu"><a href="#">menu 3.1.4</a></li> </ul> </li> <li class="submenu"><a href="#">menu 3.2</a></li> <li class="submenu"><a href="#">menu 3.3</a></li> <li class="submenu"><a href="#">3.4</a></li> <li class="submenu"><a href="#">3.5</a></li> </ul> </li> <li class="nav"><a href="#">menu 4</a></li> <li class="nav"><a href="#">menu 5</a></li> <li class="nav"><a href="#">menu 6</a></li> <li class="nav"><a href="#">menu 7</a></li> </ul> </nav>
 


