text: let prevScroll = window.pageYOffset;
  window.onscroll = () => {
    let curScroll = window.pageYOffset;
    const headerElement = document.getElementsByClassName("header")[0];
    if (prevScroll > curScroll) {
      headerElement.style.top = "0";
    } else {
      headerElement.style.top = "-25vh";
    }
    prevScroll = curScroll;
  };
  const mobileMenu = document.getElementsByClassName("link-col-mobile")[0];
  const mobileOverlay = document.getElementsByClassName("mobile-overlay")[0];
  const closeButton = document.getElementsByClassName("close-button")[0];
  mobileMenu.addEventListener("click", () => {
    mobileOverlay.style.height = "100%";
    mobileOverlay.style.opacity = "1";
  });
  closeButton.addEventListener("click", () => {
    mobileOverlay.style.height = "0";
    mobileOverlay.style.opacity = "0";
  });
  