.apres_logo{
    animation: apres_logo 1s infinite;
    padding_top:500px;
    margin-left: 200px;
    color: #FF0000;

  
}
@keyframes apres_logo{
    0%{opacity: 0;}
    25%{opacity: 0.25;}
    50%{opacity: 0;}
    75%{opacity: 0.75;}
    75%{opacity: 1;}
    150%{opacity: 0;}
}

.cadre_image{
width:300px;
height:300px;
}

.entete{
background-color: blue !important;
}