Classbind navbar

HTML

<div class="header-wrap">
<header role="banner" class="binder">
    <h1 class="title"><a href="/">App Name</a></h1>
    
    <form class="site_search">
    <input type="search" placeholder="Search" id="s">
    </form>
    
    <nav role="site-nav">
        <ul>
            <li>
                <a href="/user">
                    <img class="avatar" src="http://placedog.com/36/36" alt="Joe Bloggs" title="Joe Bloggs">
                    Joe Bloggs
                </a>
            </li>
            <li><a href="/browse">Browse</a></li>
            <li><a href="/logout">Logout</a></li>
        </ul>
    </nav>
</header>
</div>

CSS

html, body {
    font-family: Helvetica Neue, Helvetica, Arial, sans-serif;
    -webkit-font-smoothing: antialiased;
}

.binder {
    width: 960px;
    margin: 0 auto;
    padding: 0 10px;
}

.header-wrap {
    background: #A9DB80;
    background-image: -webkit-linear-gradient(rgba(0,0,0,0),rgba(0,0,0,.2));
    color: #fff;
}

.header-wrap a {
    color: #fff;
    text-shadow: 0 1px 1px rgba(0,0,0,.2);
    text-decoration: none;
    font-weight: bold;
    display: inline-block;
    line-height: 48px;
}

header[role=banner] {
    overflow: hidden;
}

.title {
    float: left;
    margin-right: 24px;
}

.site_search {
    display: block;
    float: left;
    border-left: 1px solid rgba(0,0,0,.2);
    padding-left: 23px;
    box-shadow: inset 1px 0 0 rgba(255,255,255,.2);
}

#s {
    display: block;
    vertical-align: middle;
    height: 24px;
    margin: 12px 0;
    -webkit-appearance: none;
    border-radius: 100px;
    border: 0;
    box-shadow: 0 0 0 1px rgba(0,0,0,.2), 0 2px 0 rgba(255,255,255,.2), inset 0 2px 4px rgba(0,0,0,.2);
    padding: 0 .75em;
    background: rgba(255,255,255,.7);
    -webkit-transition: all .3s ease;
}

#s:hover {
    background: rgba(255,255,255,.85);
}

#s:focus {
    background: #fff;
    outline: none;
}

nav[role=site-nav] {
    float: right;
}

nav[role=site-nav] li {
    float: left;
    display: block;
}

nav[role=site-nav] li a {
    display: block;
    float: left;
    padding: 0 .75em;
}

nav[role=site-nav] li a:hover {
    background: rgba(0,0,0,.2);
}

.avatar {
    border-radius: 4px;
    display:inline-block;
    position: relative;
    margin-top: -2px;
    vertical-align: middle;
    margin-right: 5px;
    line-height: 0;
    box-shadow: 0 0 2px 1px rgba(0,0,0,.2);
    border-radius: 4px;
}

.avatar:after {
    content: '';
    pointer-events: none;
    display: block;
    position: absolute;
    z-index: 999;
    background: -webkit-linear-gradient(rgba(255,255,255,.4),transparent 70%);
    background:   ...