.img_bkgd{
  position: absolute;
  z-index: 1;
  width: 100vw;
  height: 100vh;
  margin: 0;
  padding: 0;
  overflow: hidden;
  background-position: center;
  background-repeat: no-repeat;
  background-size: cover;
}

.hidden{
  visibility: hidden;
}

#img_galop{
  background-image: url('../img/galop.png');
}

#img_trot{
  background-image: url('../img/trot.png');
}

#contenu{
  position: absolute;
  top: 2.5vh;
  left: 2.5vw;

  width: 95vw;
  height: 95vh;

  margin: 0;
  padding: 0;
}

.ring-black{
  background-color: black;
  color: white;
}

.ring-white{
  background-color: white;
  color: black;
}

#logo{
  display: block;
  width: 25vw;
  height: 25vh;
  margin: 0 auto;
  padding: 0;
  overflow: hidden;
  background-position: center;
  background-repeat: no-repeat;
  background-size: contain;
}

.ring-white #logo{
  background-image: url('../img/galop-carre.png');
}

.ring-white.trot #logo{
  background-image: url('../img/trot-carre.png');
}

.ring-black #logo{
  background-image: url('../img/galop-blanc-carre.png');
}

/*toggle*/
.ring-black #logo.logo{
  background-image: url('../img/galop-carre.png');
}

.ring-black.trot #logo{
  background-image: url('../img/trot-blanc-carre.png');
}

#bas{
  position: absolute;
  top: 85vh;
  left: 2vw;
  font-weight: bold;
}

.ring-black button{
  background-color: black;
  color: darkgrey;
}

.ring-white button{
  background-color: white;
  color: black;
}