body {
    font-family: Arial, sans-serif;
    margin: 20px;
    padding: 20px;
    background-color: #f4f4f4;
}

header, footer {
    background-color: #333;
    color: white;
    text-align: center;
    padding: 10px;
}

nav {
    background-color: #444;
    padding: 10px;
}

nav ul {
    list-style-type: none;
    text-align: center;
}

nav li {
    display: inline-block;
}

nav li a {
    color: white;
    margin-right: 15px;
    text-decoration: none;
}

section {
    margin-top: 20px;
}

img {
    width: 80%;
    margin: 0 auto;
    display: block;
}