@media (max-width: 640px), (orientation: portrait) {
	
	section#contenedor {
		width: 100%
	}
	article.imagen {
		display: block;
		width: 100%;

		transition: all .4s linear;
		-webkit-transition: all .4s linear; 	
		-moz-transition: all .4s linear;
		-o-transition: all .4s linear;
		-ie-transition: all .4s linear;
		
	}
	





}