body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #fff;
    max-width: 600px;
    margin: 0 auto;
    padding: 40px 20px;
    font-size: 16px;
}

h1 {
    font-size: 24px;
    font-weight: normal;
    margin: 0 0 20px 0;
}

h2 {
    font-size: 20px;
    font-weight: normal;
    margin: 40px 0 20px 0;
}

nav ul {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    gap: 20px;
    margin-bottom: 40px;
}

nav li {
    margin: 0;
}

nav a {
    color: #333;
    text-decoration: none;
}

nav a:hover {
    text-decoration: underline;
}

p {
    margin: 16px 0;
}

ul {
    margin: 16px 0;
    padding-left: 20px;
}

li {
    margin: 8px 0;
}

a {
    color: #0066cc;
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

section {
    margin-bottom: 40px;
}

@media (max-width: 640px) {
    body {
        padding: 20px 15px;
    }
    
    nav ul {
        flex-direction: column;
        gap: 10px;
    }
}