body {
    font-family: Verdana;
}

article {
    border: 1px solid #ccc;
    padding: 30px;
    margin: 10px 0;
}

#page-header {
    border: 1px solid blue;
    background: green;
}

.commentaire {
    border: 1px solid blue;
    padding: 10px;
    margin: 10px 0;
}