.all{
    display: flex;
    flex-direction: column;
    justify-content: top;
    align-items: center;
    height: 100vh;
}

body{
    background-image: url(background_tableau.gif);
    background-repeat: no-repeat;
    background-position: center;
    background-size: cover;
}

table{
    border: 1px solid black; border-collapse: collapse;
    background-color: white;
}

.retour{
    background-image: url("background_nav_tab.gif");
    background-size: cover;
    background-position: center;
    position: fixed;
    left: 50px;
    top: 30px;
    display: flex;
    flex-direction: column;
    align-items: center;
    color: rgb(255, 255, 255);
    background-color: rgb(0, 0, 0);
    border: solid rgb(255, 255, 255);
    padding: 10px;
    border-radius: 10px;
    width: 13%;
    height: 2%;
}