Navigation Bar / DropDown

CSS

<style>
* {
    margin: 0px;
    padding: 0px;
}
#container ul {
    list-style:none;
}

#container ul li {
    background-color: #3c948d;
    width: 150px;
    border: 1px solid white;
    height: 50px;
    line-height: 50px;
    text-align: center;
    float: left;
    color: white;
    font-size: 18px;
    position: relative;
}
#container ul li:hover {
    background-color: #388222;
}
#container ul ul {
    display: none;
}

#container ul li:hover > ul {
    display: block;
}

</style>

HTML

<div id="container">
        <ul>
            <li>HOME</li>
            <li>ABOUT</li>
            <li>Entertain
                <ul>
                    <li>view</li>
                    <li>search</li>
                </ul>
            </li>
            <li>Board</li>
        </ul>
    </div>