body {
    max-width: 700px;
    margin: auto;
}

nav ul {
    list-style-type: none;
    margin: 0 auto;
    padding: 0;
    overflow: hidden;
}

nav li {
    float: left;
}

nav li a {
    display:block;
    text-align:center;
    color: black;
    padding: 1px 20px;
    text-decoration: none;
}

nav li a:hover {
    text-decoration: underline;
}

.active {
    font-weight: bold;
}