body {
    color: black;
    font-family: ui-serif, Georgia, "Times New Roman", Times, serif;
    background-image: url("rgb_background.jpg");
    /*background-attachment: fixed;*/
    /*background-size: cover;*/
    margin: 0;
    padding: 0;
}

main {
    background-color: whitesmoke;
    border: 1px solid darkgrey;
    color: #333333;
    padding: 20px;

    /* Centering logic */
    width: 60%;
    max-width: 900px;  /* Prevents it from getting too wide on huge monitors */
    margin: 50px auto; /* 50px top/bottom, 'auto' centers it horizontally */
}

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

nav li {
    display: inline;
    margin-right: 15px;
}