body {
    font-family: Verdana, Tahoma, sans-serif;
    font-size: 18px;
}

nav {
    width: 200px;
    height: 100%;
    position: fixed;
    top: 0;
    left: 0;
    padding: 40px 20px;
    box-sizing: border-box;

    background-color: rgb(100, 100, 100);
    color: white;
}

nav ul {
    list-style: none;
    padding: 0px;
}

nav a {
    color: white;
    text-decoration: none;
    display: block;
    padding: 12px 4px;
}

nav a:hover {
    color: navajowhite
}

section {
    margin-left: 220px;
    max-width: 800px;
}

.source {
    text-align: right;
    font-style: italic;
}