<script>

 
const timeline = document.getElementsByClassName('timeline01')[0];
const timelineLine = document.getElementsByClassName('timeline__line')[0];

document.addEventListener('scroll', function() {
  if (!timeline) return;
  let scrollPercentage = (window.scrollY - timeline.offsetTop) / (timeline.offsetHeight - window.innerHeight) * 100;
  if (scrollPercentage < 0) scrollPercentage = 0;
  if (scrollPercentage > 100) scrollPercentage = 100;
  timelineLine.style.height = scrollPercentage + '%';
});
  
  
  
const timelineContent = document.querySelector('.timeline01__content');
let firstDiv = null;
let lastDiv = null;

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

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

const timelineContentBar = document.querySelector('.timeline01__content__bar');
timelineContentBar.style.height = "calc(100% - " + averageDivHeight + "px)";

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



</script>