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<nav>
    <ul>
        <li><a href="#">Home</a></li>
        <li><a href="#">Tutoriais</a>
            <ul>
                <li><a href="#">CSS</a></li>
                <li><a href="#">HTML</a></li>
                <li><a href="#">JavaScript</a>
                    <ul>
                        <li><a href="#">jQuery</a></li>
                        <li><a href="#">Angular</a></li>
                    </ul>
                </li>
            </ul>
        </li>
        <li><a href="#">Artigos</a>
            <ul>
                <li><a href="#">Node.js</a></li>
                <li><a href="#">MongoDB</a></li>
            </ul>
        </li>
        <li><a href="#">Crie seu PrĂ³prio Menu</a></li>
    </ul>
</nav>
nav ul ul {
    display: none;
}
nav ul li:hover > ul {
    display: block;
}
nav {
    margin: 0 auto;
    text-align: center;
}
nav ul {
	background: #efefef; 
	background: linear-gradient(top, #efefef 0%, #bbbbbb 100%);  
	background: -moz-linear-gradient(top, #efefef 0%, #bbbbbb 100%); 
	background: -webkit-linear-gradient(top, #efefef 0%,#bbbbbb 100%); 
	box-shadow: 0px 0px 9px rgba(0,0,0,0.15);
	padding: 0 20px;
	border-radius: 10px;  
	list-style: none;
	position: relative;
	display: inline-table;
}
	nav ul:after {
		content: ""; clear: both; display: block;
	}