let observerMarginBottom = document.documentElement.clientHeight - document.getElementById("header").offsetHeight,
observerMargin = "0px 0px -" + observerMarginBottom + "px 0px",
observerOptions = {
rootMargin: observerMargin,
threshold: 0
};
.penci-archive__list_posts .entry-media img {
padding-top: 56% !important;
}