* {
    box-sizing: border-box;
    padding: 0;
    margin: 0;
}

.batman
/* posicionamiento */
    {
    position: fixed;
    top: 50%;
    left: 50%;
    border-radius: 50%;
    transform: translate(-50%, -50%);
    /* INVESTIGACIÓN */
    /* estilo */
    min-width: 700px;
    height: 500px;
    background-size: contain;
    background-repeat: no-repeat;
    background-position: center;
    background-image: url(../img/batmanOFF.jpg);
}

.batman_activo {
    background-image: url(../img/batmanON.gif);
}

.bati_boton {
    margin: 291px auto 0;
    border: 1px solid red;
    width: 30px;
    height: 50px;
}