body {
    max-width: 800px;
    margin: 0 auto;
    padding: 1rem;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    line-height: 1.6;
}

header {
    border-bottom: 1px solid #eee;
    padding-bottom: 1rem;
    margin-bottom: 2rem;
}

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

nav ul li {
    display: inline;
    margin-right: 1rem;
}

article {
    margin-bottom: 2rem;
}

footer {
    margin-top: 2rem;
    padding-top: 1rem;
    border-top: 1px solid #eee;
    text-align: center;
}