Edit in JSFiddle

<nav>
    <a href="#nav" id="nav"><i class="fa fa-bars"></i></a>
    <a href="#" class="close"><i class="fa fa-bars"></i></a>
    <ul>
        <li>a</li>
        <li>b</li>
        <li>c</li>
        <li>d</li>
    </ul>
</nav>

nav > ul {
	border: 1px solid #222;
	left: -80px;
    list-style-type:none;
	margin: 0;
    padding:5px 20px;
	position: absolute;
	top: 45px;
			transition:all .3s ease;
	-webkit-transition:all .3s ease;
}

nav > .close,
a#nav:target {
    display: none;
}

a:target ~ ul,
a:target ~ .close {
    display: inline-block;
}

a:target ~ ul {
    left: 0;
}