<script>

  
const timelineContent = document.querySelector('.fb-timeline-one__list');
let firstDiv = null;
let lastDiv = null;

for (let i = 0; i < timelineContent.children.length; i++) {
  let child = timelineContent.children[i];
  if (child.nodeName === "LI") {
    if (!firstDiv) {
      firstDiv = child;
    }
    lastDiv = child;
  }
}

const firstDivHeight = firstDiv.offsetHeight;
const lastDivHeight = lastDiv.offsetHeight;
const averageDivHeight = (firstDivHeight + lastDivHeight) / 2;

const timelineContentBar = document.querySelector('.fb-timeline-one__bar');
timelineContentBar.style.height = "calc(100% - " + averageDivHeight + "px)";

const topPosition = firstDivHeight / 2;
timelineContentBar.style.top = topPosition + "px";



</script>