.navbar {
  position: fixed;
  top: 0;
  width: 100%;
  transition: transform 0.3s ease-in-out;
}

.navbar.hidden {
  transform: translateY(-100%);
}

let lastScrollPosition = 0;
const navbar = document.querySelector('.navbar');

window.addEventListener('scroll', () => {
  const currentScrollPosition = window.pageYOffset;
  
  if (currentScrollPosition <= 0) {
    // 在页面顶部显示导航栏
    navbar.classList.remove('hidden');
    return;
  }
  
  if (currentScrollPosition > lastScrollPosition) {
    // 向下滚动时隐藏
    navbar.classList.add('hidden');
  } else {
    // 向上滚动时显示
    navbar.classList.remove('hidden');
  }
  
  lastScrollPosition = currentScrollPosition;
});

window.decorView.systemUiVisibility = (
    View.SYSTEM_UI_FLAG_LAYOUT_STABLE
    or View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
    or View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
    or View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY
)

override var prefersStatusBarHidden: Bool {
    return true
}

// 隐藏导航栏
navigationController?.setNavigationBarHidden(true, animated: true)

body {
  padding-top: [导航栏高度]px;
}

.navbar {
  position: fixed;
  top: 0;
  width: 100%;
  height: [导航栏高度]px;
  transition: transform 0.3s ease-in-out;
}