body {
    font-family: 'Courier New', Courier, monospace;
    background-color: #f4f4f4;
    color: #333;
    margin: 0;
    padding: 0;
}
header, section, footer {
    text-align: center;
    margin: 20px;
}
nav ul {
    list-style-type: none;
    padding: 0;
}
nav ul li {
    display: inline;
    margin-right: 10px;
}
a {
    text-decoration: none;
    color: #333;
}
a:hover {
    text-decoration: underline;
}
article {
    background-color: #fff;
    padding: 20px;
    margin-top: 20px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}