.img_left {
  float: left;
  margin-right: 30px;
  margin-bottom: 8px;
}
.img_right {
  float: right;
  margin-left: 12px;
  margin-bottom: 8px;

}

.gallery_img { max-width:100%; }
.size-20 { width: 20%;}
.size-50 { width: 50%;}
.size-100 { width: 100%;}

	
@media (max-width: 480px) {
	.img_left, .img_right {width: 100%; margin: 0px; margin-bottom: 15px;}
}