body {
    font-family: 'Open Sans', sans-serif;
    margin: 0;
    padding: 0;
    color: #333;
    background-color: #f8f8f8;
}

header {
    background-color: #003366;
    color: #ffffff;
    padding: 20px;
    text-align: center;
    position: relative;
}

header h1 {
    margin: 0;
    font-size: 24px;
    display: inline-block;
    padding: 10px 20px;
    border: 2px solid #ffffff; /* Cadre blanc fin */
    border-radius: 5px; /* Bordures arrondies */
}

header p {
    margin: 5px 0 15px;
    font-size: 18px;
}

nav ul {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    justify-content: center;
    background-color: #004080;
}

nav ul li {
    margin: 0 10px;
}

nav ul li a {
    text-decoration: none;
    color: #ffffff;
    font-weight: bold;
    display: block;
    padding: 10px 20px;
    border-radius: 5px;
}

nav ul li a:hover {
    background-color: #0059b3;
}

main {
    padding: 20px;
}

section {
    margin-bottom: 40px;
}

section img {
    display: block;
    margin: 0 auto;
}

section p, section ul {
    max-width: 800px;
    margin: 20px auto;
    line-height: 1.6;
}

footer {
    background-color: #003366;
    color: #ffffff;
    text-align: center;
    padding: 10px 0;
    position: fixed;
    width: 100%;
    bottom: 0;
}

@media (max-width: 768px) {
    header h1 {
        font-size: 18px;
    }

    header p {
        font-size: 16px;
    }

    nav ul {
        flex-direction: column;
    }

    nav ul li {
        margin: 5px 0;
    }

    nav ul li a {
        padding: 8px 16px;
    }

    main {
        padding: 10px;
    }

    section p, section ul {
        margin: 10px auto;
    }
}