ソーシャルメディアヘッダーコンポーネント

<header class="bg-white dark:bg-gray-900 text-gray-800 dark:text-white shadow-md">
  <div class="container mx-auto px-4 py-4 flex justify-between items-center">
    <div class="flex items-center space-x-4">
      <h1 class="text-2xl font-bold">SocialNet</h1>
      <nav class="hidden md:flex space-x-4">
        <a href="#" class="hover:text-blue-500 dark:hover:text-blue-400">Feed</a>
        <a href="#" class="hover:text-blue-500 dark:hover:text-blue-400">Profile</a>
        <a href="#" class="hover:text-blue-500 dark:hover:text-blue-400">Messages</a>
        <a href="#" class="hover:text-blue-500 dark:hover:text-blue-400">Notifications</a>
      </nav>
    </div>
    <div class="flex items-center space-x-4">
      <div class="relative">
        <input type="text" placeholder="Search..." class="px-4 py-2 rounded-full border border-gray-300 dark:border-gray-700 focus:outline-none focus:ring-2 focus:ring-blue-500 dark:focus:ring-blue-400 bg-gray-100 dark:bg-gray-800 text-gray-800 dark:text-white">
        <svg xmlns="http://www.w3.org/2000/svg" class="h-5 w-5 absolute right-3 top-3 text-gray-400" fill="none" viewBox="0 0 24 24" stroke="currentColor">
          <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" />
        </svg>
      </div>
      <button class="md:hidden">
        <svg xmlns="http://www.w3.org/2000/svg" class="h-6 w-6" fill="none" viewBox="0 0 24 24" stroke="currentColor">
          <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M4 6h16M4 12h16M4 18h16" />
        </svg>
      </button>
      <div class="relative">
        <img src="https://randomuser.me/api/portraits/men/32.jpg" alt="User Avatar" class="w-10 h-10 rounded-full cursor-pointer">
        <span class="absolute bottom-0 right-0 w-3 h-3 bg-green-500 rounded-full border-2 border-white dark:border-gray-900"></span>
      </div>
    </div>
  </div>
  <div class="container mx-auto px-4 py-2 md:hidden bg-gray-200 dark:bg-gray-800">
    <nav class="flex justify-around text-sm">
      <a href="#" class="hover:text-blue-500 dark:hover:text-blue-400">Feed</a>
      <a href="#" class="hover:text-blue-500 dark:hover:text-blue-400">Profile</a>
      <a href="#" class="hover:text-blue-500 dark:hover:text-blue-400">Messages</a>
      <a href="#" class="hover:text-blue-500 dark:hover:text-blue-400">Notifications</a>
    </nav>
  </div>
</header>