@media (min-width: 780px) {
    .header {
        position: fixed;
        background-color: white;
       
        z-index: 1000;
    }
}
.image_container .caption {
	background: rgba(126, 125, 125, 0.35);
	color: #fff;
	padding: 8px 12px;
	font-size: .8667rem;
	border-radius: 3px;
	line-height: 1.3;
	display: inline-block;
	margin-top: 5px;
}