.pos_img {
  position: absolute;
  top: 0px;
  left: 0px;
}

.gauche {
	float: left;
	margin:20px;
	}

.droite {
	float: right;
	margin:20px;
	}
	
.pos_block {
  // position: relative;
  // left: 0px;
  color: white;
}	

.img_descro {
	background-image: url(images/colonne.jpg);
	background-repeat:no-repeat;
}