body{
background-repeat:no-repeat;
background-image:url(fond.png);
background-size: cover;
background-position: center; 
font-family: "Segoe ui", "Segoe ui", Sans-Serif;
text-align:center;
margin:auto;
vertical-align:middle;
font-size:120%;
min-width:520px;
max-width:80%;
min-height:50%;
max-height:90%;
}
fieldset{
text-align:center;
margin:auto;
vertical-align:middle;
}
legend{
text-align:center;
margin:auto;
vertical-align:middle;
}
table{
border:0;
margin:auto;
vertical-align:middle;
}
p.cEchec {
visibility:hidden;
color:red;
text-align:center;
}