header {
    font-family: Arial, Helvetica, sans-serif;
    font-size: 2rem;
}

nav ul {
    list-style-type: none;
    border-left: 1px solid black;
    margin: 0;
    padding: 0;
}

    nav ul li {
        display: inline-block;
        border-right: 1px solid black;
        padding: 2px 10px;
        margin: 0;
    }