.structure-img{
	margin-top:20px; 
	width: 100%;
	text-align: center;
}
.structure-img img{
	width: 80%;
}

@media (max-width: 479px) {
	.structure-img img{
		width: 100%;
	}
}
@media (min-width: 480px) and (max-width: 767px) {
	.structure-img img{
		width: 90%;
	}
}