a.bulle { 
position:relative;
color:#C800F0;
text-decoration:none;
font-family:arial, verdana, sans-serif;
text-align:center;
}

a.bulle:hover {
background: none;
z-index: 50;
}

a.bulle span {
display: none;
}

a.bulle:hover span {
display: block;
position: absolute;
top: -40px; 
left: 0px; 
font-family:arial, verdana, sans-serif;
text-align:left;
font-size:17px;
color:#60b0f7;
font-weight:normal;
width:200px;
background: white;
padding: 5px;
border: #62c0f4 solid 1px ;
text-indent: 0;
}