/*-------------------------------------------------------
  Réglages généraux
-------------------------------------------------------*/

html,
body {
    margin: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
    background: #111;
    font-family: Arial, Helvetica, sans-serif;
}


/*-------------------------------------------------------
  Image de fond
-------------------------------------------------------*/

#fond {
    position: fixed;
    top: 0;
    left: 0;

    width: 100%;
    height: 100%;

    object-fit: contain;

    z-index: 1;
}


/*-------------------------------------------------------
  Bouton Retour
-------------------------------------------------------*/

#retour {

    position: absolute;

    top: 30px;
    left: 30px;

    min-width: 200px;
    padding: 15px 30px;

    font-size: 18px;
    font-weight: bold;

    color: white;
    background: green;

    border: 2px solid white;
    border-radius: 10px;

    cursor: pointer;

    transition: .2s;
    z-index: 2;
}

#retour:hover {

    background: cyan;
    color: black;
    border-color: black;
}


/*-------------------------------------------------------
  Bouton graphique
-------------------------------------------------------*/

.clic {

    position: absolute;

    bottom: 40px;
    right: 40px;

    width: 200px;
    height: 200px;
    z-index: 2;

    transition: transform .10s ease;
}

.clic:active {

    transform: scale(.90);
}


/*-------------------------------------------------------
  Petits écrans
-------------------------------------------------------*/

@media (max-width:800px) {

    /* centre le bouton graphique */

    .clic {
        width: 140px;
        height: 140px;

        right: calc(50% - 70px);
    }

    /* centre le bouton Retour */

    #retour {

        left: calc(50% - 100px);
    }

}