body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    line-height: 1.6;
    max-width: 800px;
    margin: 0 auto;
    padding: 2rem;
    color: #333;
}
h1 {
    border-bottom: 1px solid #eee;
    padding-bottom: 0.5rem;
}
h2 {
    margin-top: 2rem;
}
h3 {
    margin-top: 1.5rem;
}
h4 {
    margin-top: 1rem;
}
ul {
    padding-left: 1.5rem;
}
li {
    margin-bottom: 0.5rem;
}
a {
    color: #007aff;
    text-decoration: none;
}
a:hover {
    text-decoration: underline;
}
.nav {
    margin-bottom: 1.5rem;
}