// フッター上で追従ボタンを非表示
const button = document.querySelector(".fixed-btn");
const footer = document.querySelector("footer");

window.addEventListener("scroll", () => {
  const buttonRect = button.getBoundingClientRect();
  const footerRect = footer.getBoundingClientRect();

  if (buttonRect.bottom > footerRect.top) {
    button.style.opacity = "0";
  } else {
    button.style.opacity = "1";
  }
});