body {
    font-family: Arial, sans-serif;
    background-color: #f9f9f9;
    color: #333;
    margin: 0;
    padding: 0;
}
header {
    background-color: #003366;
    color: white;
    padding: 20px;
    text-align: center;
}
nav ul {
    display: flex;
    justify-content: center;
    list-style: none;
    background-color: #f1f1f1;
    padding: 10px 0;
    margin: 0;
}
nav ul li {
    margin: 0 15px;
}
nav ul li a {
    text-decoration: none;
    color: #003366;
}
main {
    padding: 20px;
    max-width: 900px;
    margin: auto;
}
section, img {
    margin-bottom: 30px;
    max-width: 100%;
}
footer {
    text-align: center;
    padding: 20px;
    background-color: #003366;
    color: white;
}