nav {
    background-color: #ddd;
    overflow: hidden;
}
nav a {
    float: left;
    color: black;
    text-align: center;
    padding: 14px 16px;
    text-decoration: none;
    font-size: 17px;
    height: 18px;
}
nav a:hover {
    background-color: #888;
    color: black;
}
nav a.active {
    background-color: #55a;
    color: white;
}
nav div.rightside {
    float: right;
}