Back to Top Button 组件

<div class="fixed bottom-6 right-6">
  <a href="#top" class="group relative flex items-center justify-center p-3 rounded-full bg-blue-500 text-white shadow-lg transition-all duration-300 ease-in-out hover:scale-110 focus:outline-none focus:ring-4 focus:ring-blue-300 dark:bg-blue-700 dark:hover:scale-110 dark:focus:ring-blue-800">
    <svg class="w-6 h-6 transform transition-transform duration-300 group-hover:-translate-y-1 group-hocus:-translate-y-1" fill="none" stroke="currentColor" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg">
      <path strokeLinecap="round" strokeLinejoin="round" strokeWidth="2" d="M8 7l4-4m0 0l4 4m-4-4v18"></path>
    </svg>
    <span class="absolute top-1/2 left-1/2 -translate-x-1/2 -translate-y-1/2 text-xs font-semibold opacity-0 group-hover:opacity-100 group-focus:opacity-100 transition-opacity duration-300 delay-150">Back to Top</span>
  </a>
</div>