.accueil{
    position:absolute;
    top:0;
    left:0;
    width: 100vw;
    height: 100vh;
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
}

.accueil img{
    width: 100%;
      height: auto;
      object-fit: cover;
      object-position: center;
      z-index:-1;
}