.cadre_pages {
  border: 1px solid black;
}

.cadre_pages_lien {
  border: 2px solid red;
}

#affich_page {
  padding: 20px;
  width: 900px;
}
#affich_navigation{
  width: 900px;
  height: 50px;
  padding: 5px;
  margin-top: 10px;
  text-align: center;
}