body {
    font-family: 'Courier New', Courier, monospace;
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

header, footer {
    background-color: #333;
    color: white;
    text-align: center;
    padding: 1rem 0;
}

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

nav ul li {
    display: inline;
    margin: 0 15px;
}

nav ul li a {
    color: white;
    text-decoration: none;
}

main {
    max-width: 800px;
    margin: 20px auto;
    padding: 0 20px;
}

a {
    color: #007BFF;
}