(function () {
  var scrollTopButtons = document.querySelectorAll(".home-mobile-footer-top");
  scrollTopButtons.forEach(function (button) {
    button.addEventListener("click", function () {
      window.scrollTo({ top: 0, behavior: "smooth" });
    });
  });

  // 页脚进入视口后，把悬浮按钮（下载 App / 回到顶部）顶到页脚上方，避免遮住页脚内容。
  var footers = document.querySelectorAll(".footer-box, .home-mobile-footer");
  if (!footers.length) return;
  var root = document.documentElement;
  var ticking = false;
  var lastLift = -1;

  function visibleFooter() {
    for (var i = 0; i < footers.length; i++) {
      if (footers[i].offsetHeight > 0) return footers[i];
    }
    return null;
  }

  function update() {
    ticking = false;
    var footer = visibleFooter();
    var lift = 0;
    if (footer) {
      var top = footer.getBoundingClientRect().top;
      lift = Math.max(0, Math.round((window.innerHeight || 0) - top));
    }
    if (lift === lastLift) return;
    lastLift = lift;
    root.style.setProperty("--footer-lift", lift + "px");
  }

  function schedule() {
    if (ticking) return;
    ticking = true;
    window.requestAnimationFrame(update);
  }

  window.addEventListener("scroll", schedule, { passive: true });
  window.addEventListener("resize", schedule);
  schedule();
})();