CSS3 Drop Down Menu - After:psuedo-element

CSS3 Drop Down Menu - After:psuedo-element

HTML

<nav>
    <ul class="main">
        <li><a href="#">About</a>
            <ul class="secondary">
                <li><a href="#">Learn About Us</a></li>
                <li><a href="#">Nice things to know</a></li>
            </ul>        
        </li>
        <select name="selectevent">
        <li><a href="#">Products</a>
            <ul class="secondary">
                <li><a href="#"><option name="test">test</option></a></li>
                <li><a href="#"><option name="test">test</option></a></li>
                
            </ul>        
        </li>
        </select>
        <li><a href="#">Features</a>
            <ul class="secondary">
                <li><a href="#">Something Nice</a></li>
                <li><a href="#">Another nice thing</a></li>
            </ul>        
        </li>
    </ul>
</nav>

CSS

nav .main {
    font-size: 1em;
    margin: 0;
    padding: 0;
    list-style: none;
}

.main > li {
    display: block;
    position: relative;
    float: left;
}

.main > li a {
    display: block;
    text-decoration: none;
    color:#FFF;
    border-top: 1px solid #ffffff;
    padding: 5px 15px 5px 15px;
    background: #1e7c9a;
    margin-left: 1px;
    white-space: nowrap;
}

.main > li a:hover {
    background: #3b3b3b;
    color:#FFF;
}

.secondary {
    display:none;
    list-style: none;
    margin: 0;
    padding: 0;
}


.main li:hover .secondary {
    display: block;
    position: absolute;
    top:40px;
}

.main li:hover ul li {
    float: none;
    font-size: 1em;
}

.main > li:hover a { background: #3b3b3b; }
.main > li:hover li a:hover {
    background: #1e7c9a;
}
.main > li:hover:after {
    content:'';
    display:block;
    width:100%;
    height:10px;
    border-bottom:10px solid #1e7c9a;
    border-right: 10px solid transparent; 
    position:absolute;
    top:20px;
    margin-left:1px;
}