body, html {
margin:0;
padding:0;
width:100%;
height:100%;
}
.terre{
float:left;
background-color:#000000;
width:33%;
height:100%;
}
.or{
float:left;
background-color:#FFFF00;
width:33%;
height:100%;
}
.sang{
float:left;
background-color:#FF0000;
width:33%;
height:100%;
}