Componente di navigazione permanente

<nav class="sticky top-0 z-50 bg-white dark:bg-gray-900 shadow-md">
  <div class="container mx-auto px-4 py-3 flex items-center justify-between">
    <!-- Logo -->
    <a href="#" class="text-2xl font-bold text-indigo-600 dark:text-indigo-400">YourStore</a>

    <!-- Search Bar (hidden on small screens, shown on medium and up) -->
    <div class="hidden md:flex items-center flex-grow mx-4 relative">
      <input type="text" placeholder="Search products..." class="w-full py-2 pl-10 pr-4 rounded-full bg-gray-100 dark:bg-gray-800 text-gray-800 dark:text-white focus:outline-none focus:ring-2 focus:ring-indigo-500">
      <svg class="absolute left-3 top-1/2 transform -translate-y-1/2 text-gray-400 dark:text-gray-500 w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M21 21l-6-6m2-5a7 7 0 11-14 0 7 7 0 0114 0z"></path></svg>
    </div>

    <!-- Navigation Icons -->
    <div class="flex items-center space-x-4">
      <!-- Cart Icon -->
      <a href="#" class="relative p-2 rounded-full hover:bg-gray-100 dark:hover:bg-gray-800 transition duration-300">
        <svg class="w-6 h-6 text-gray-600 dark:text-gray-300" fill="none" stroke="currentColor" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M3 3h2l.4 2M7 13h10l4-8H5.4M7 13L5.4 5M7 13l-2.293 2.293c-.63.63-.184 1.707.707 1.707H17m0 0a2 2 0 100 4 2 2 0 000-4zm-8 4a2 2 0 11-4 0 2 2 0 014 0z"></path></svg>
        <span class="absolute top-0 right-0 inline-flex items-center justify-center px-2 py-1 text-xs font-bold leading-none text-red-100 transform translate-x-1/2 -translate-y-1/2 bg-red-600 rounded-full">3</span>
      </a>

      <!-- User Avatar -->
      <a href="#" class="p-1 rounded-full focus:outline-none focus:ring-2 focus:ring-indigo-500">
        <img class="w-8 h-8 rounded-full" src="https://randomuser.me/api/portraits/men/32.jpg" alt="User Avatar">
      </a>

      <!-- Mobile Menu Button (shown on small screens) -->
      <button class="md:hidden p-2 rounded-full hover:bg-gray-100 dark:hover:bg-gray-800 transition duration-300">
        <svg class="w-6 h-6 text-gray-600 dark:text-gray-300" fill="none" stroke="currentColor" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M4 6h16M4 12h16M4 18h16"></path></svg>
      </button>
    </div>
  </div>

  <!-- Mobile Search Bar (shown on small screens, hidden on medium and up) -->
  <div class="md:hidden px-4 py-2">
    <div class="relative">
      <input type="text" placeholder="Search products..." class="w-full py-2 pl-10 pr-4 rounded-full bg-gray-100 dark:bg-gray-800 text-gray-800 dark:text-white focus:outline-none focus:ring-2 focus:ring-indigo-500">
      <svg class="absolute left-3 top-1/2 transform -translate-y-1/2 text-gray-400 dark:text-gray-500 w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M21 21l-6-6m2-5a7 7 0 11-14 0 7 7 0 0114 0z"></path></svg>
    </div>
  </div>
</nav>