.login_connexion {
position:absolute;
   top: 50%;  /* position the top  edge of the element at the middle of the parent */

    transform: translate(0, -50%); 
right:15%;
width:30%;
z-index:2;
}

.login_blocinfos2 {
position:absolute;
top:10%;
bottom:10%;
left:15%;
width:35%;
z-index:3;
background-color: rgba(0, 0, 0, 0.5);
color:white;

}
.login_logo {
position:absolute;
right:0;
top:0;
background-color:white;
}

.login_blocinfostitre {
position:absolute;
top:40%;
font-size:190%;
text-align:center;
width:100%;
font-weight:bold;
}
.login_blocinfosinfos {
position:absolute;
top:50%;
width:80%;
left:10%;
font-size:110%;
right:10%;
text-align:center;
}