header {
    display: block;
    position: fixed;
    left: 0;
    top: 0;
    width: 100%;
    background-color: black;
    color: white;
    text-align: center;
}

body
{
    background-color: #a6a6a6;
}

h1
{
    text-align: center;
}

.texte_centre
{
    text-align: center;
    font-size: 1.5em;
}

.bouton_index
{
    display: block;
    margin-left: auto;
    margin-right: auto;
    width: 10em;
    background-color: #663300;
    border: 0.3em solid black;
    color: black;
    font-size: 1.2em;
    text-align: center;
}
.bouton_siteboucle_1
{
    display: block;
    margin-left: auto;
    margin-right: auto;
    width: 10em;
    background-color: #00ccff;
    border: 0.3em solid black;
    color: black;
    font-size: 1.2em;
    text-align: center;
}

.bouton_siteboucle_2
{
    display: block;
    margin-left: auto;
    margin-right: auto;
    width: 10em;
    background-color: #009900;
    border: 0.3em solid black;
    color: black;
    font-size: 1.2em;
    text-align: center;
}

.post_boucle
{
  position: relative;
  left: 0;
  top: 0;
  width: 100%;
  background-color: black;
  color: white;
  font-size: 2em;
  text-align: center;
}

.bouton_piège
{
    display: block;
    margin-left: auto;
    margin-right: auto;
    width: 10em;
    background-color: #0000ff;
    border: 0.3em solid black;
    color: black;
    font-size: 1.2em;
    text-align: center;
}

.bouton_piege_sb1
{
    width: 10em;
    background-color: #009900;
    border: 0.3em solid black;
    color: black;
    font-size: 1.2em;
    text-align: center;
}

.bouton_piege_sb2
{
    width: 10em;
    background-color: #00ccff;
    border: 0.3em solid black;
    color: black;
    font-size: 1.2em;
    text-align: center;
}

.footer 
{
  position: fixed;
  left: 0;
  bottom: 0;
  width: 100%;
  background-color: black;
  color: white;
  text-align: center;
}