body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

header {
    background-color: #333;
    color: #fff;
    padding: 20px;
    text-align: center;
}

header .btn {
    background-color: #f04;
    color: #fff;
    padding: 10px 20px;
    text-decoration: none;
    border-radius: 5px;
}

#services, #realisations, #testimonials, #contact {
    padding: 20px;
    margin: 20px;
}

.service, .gallery img {
    margin: 10px 0;
}

.btn {
    background-color: #333;
    color: white;
    padding: 10px;
    border: none;
    cursor: pointer;
}

form input, form textarea {
    width: 100%;
    padding: 10px;
    margin: 5px 0;
}