body {
    font-family: Helvetica, sans-serif;
}

main h1 {
    text-align: center;
}

nav {
    width: fit-content;
    margin: 0 auto;
}

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

nav li {
    margin: 0.5em 0;
}

#indextitle {
    text-align: center;
}

#indexlist {
    margin: 0 auto;
}

#indexlist tr.odd {
    background-color: lightblue;
}

a {
    text-decoration: none;
    color: blue;
}

a:visited {
    color: darkred;
}

.indexhead a {
    color: blue;
}