body {
    display: flex;
    font-family: monospace;
    font-size: 14px;
    justify-content: center;
}
div {
    width: 504px;
}
ul {
    list-style: none;
}
@media (prefers-color-scheme: dark) {
    body {
        background: black;
        color: white;
    }
    a:link {
        color: lightgreen;
    }
    a:visited {
        color: yellow;
    }
}