body {
    background-color: white;
    text-align: center;
    color: black;
}

nav {
    background: black;
    height: 50px;
}

    nav ul {
        height: 50px;
        width: 650px;
        margin: 0 auto;
    }

        nav ul li {
            list-style-type: none;
            float: left;
            width: 150px;
        }

li a {
    color: white;
    text-align: center;
    line-height: 50px;
    display: block;
}

    li a:hover {
        background-color: white;
        color: black;
    }