document.addEventListener("nav", (e) => {
  const observer = new IntersectionObserver((entries) => {
    for (const entry of entries) {
      const parentUl = entry.target.parentElement
      if (!parentUl) return
      if (entry.isIntersecting) {
        parentUl.classList.remove("gradient-active")
      } else {
        parentUl.classList.add("gradient-active")
      }
    }
  })

  const ul = document.getElementById("list-0")
  if (!ul) return

  const end = ul.querySelector(".overflow-end")
  if (!end) return

  observer.observe(end)
})