body {
  margin: 0;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
  background : url(fond-index.png);
  background-size: cover;
  background-color: #000;
}

.wrapper {
  position: relative;
  width: 100%;
  height: 100%;
  overflow: hidden;
}

.curtain {
  position: absolute;
  top: 0;
  bottom: 0;
  
  width: 50%;
  transition: all 2s ease-in-out;
}
.center{
	z-index:99;
	left: auto;
	right: auto;
}

.left {
	background : url(gauche.png);
  left: 0;
}

.right {
	background : url(droit.png);
  right: 0;
}

.wrapper.open .left {
	background : url(gauche.png);
  transform: translateX(-100%);
}

.wrapper.open .right {
	background : url(droit.png);
  transform: translateX(100%);
}