スティッキーナビゲーションコンポーネント

<nav class="sticky top-0 z-50 bg-white shadow-md dark:bg-gray-800 transition duration-300">
  <div class="container mx-auto px-4 py-3 flex justify-between items-center">
    <!-- Logo/Brand Name -->
    <a href="#" class="text-2xl font-bold text-blue-700 dark:text-blue-400 hover:text-blue-800 dark:hover:text-blue-300 transition duration-200">
      JobBoard
    </a>

    <!-- Navigation Links - Desktop -->
    <div class="hidden md:flex space-x-6">
      <a href="#" class="text-gray-700 dark:text-gray-300 hover:text-blue-700 dark:hover:text-blue-400 font-medium transition duration-200">Jobs</a>
      <a href="#" class="text-gray-700 dark:text-gray-300 hover:text-blue-700 dark:hover:text-blue-400 font-medium transition duration-200">Companies</a>
      <a href="#" class="text-gray-700 dark:text-gray-300 hover:text-blue-700 dark:hover:text-blue-400 font-medium transition duration-200">Candidates</a>
      <a href="#" class="text-gray-700 dark:text-gray-300 hover:text-blue-700 dark:hover:text-blue-400 font-medium transition duration-200">About Us</a>
      <a href="#" class="text-gray-700 dark:text-gray-300 hover:text-blue-700 dark:hover:text-blue-400 font-medium transition duration-200">Contact</a>
    </div>

    <!-- Action Buttons - Desktop -->
    <div class="hidden md:flex space-x-4">
      <a href="#" class="px-4 py-2 rounded-md border border-gray-300 text-gray-700 dark:text-gray-300 hover:bg-gray-100 dark:hover:bg-gray-700 transition duration-200">
        Sign In
      </a>
      <a href="#" class="px-4 py-2 rounded-md bg-blue-600 text-white hover:bg-blue-700 focus:outline-none focus:ring-2 focus:ring-blue-500 focus:ring-opacity-50 transition duration-200">
        Post a Job
      </a>
    </div>

    <!-- Mobile Menu Button (Hamburger) -->
    <div class="md:hidden">
      <button type="button" class="text-gray-700 dark:text-gray-300 hover:text-blue-700 dark:hover:text-blue-400 focus:outline-none focus:ring-2 focus:ring-blue-500 focus:ring-opacity-50" aria-label="Toggle menu">
        <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 12h16m-7 6h7" />
        </svg>
      </button>
    </div>
  </div>

  <!-- Mobile Menu (Hidden by default, shown by JS in a real app) -->
  <div class="md:hidden flex flex-col space-y-2 p-4 border-t border-gray-200 dark:border-gray-700" style="display: none;">
    <a href="#" class="block text-gray-700 dark:text-gray-300 hover:text-blue-700 dark:hover:text-blue-400 py-2 transition duration-200">Jobs</a>
    <a href="#" class="block text-gray-700 dark:text-gray-300 hover:text-blue-700 dark:hover:text-blue-400 py-2 transition duration-200">Companies</a>
    <a href="#" class="block text-gray-700 dark:text-gray-300 hover:text-blue-700 dark:hover:text-blue-400 py-2 transition duration-200">Candidates</a>
    <a href="#" class="block text-gray-700 dark:text-gray-300 hover:text-blue-700 dark:hover:text-blue-400 py-2 transition duration-200">About Us</a>
    <a href="#" class="block text-gray-700 dark:text-gray-300 hover:text-blue-700 dark:hover:text-blue-400 py-2 transition duration-200">Contact</a>
    <a href="#" class="block px-4 py-2 rounded-md border border-gray-300 text-gray-700 dark:text-gray-300 hover:bg-gray-100 dark:hover:bg-gray-700 text-center transition duration-200 mt-2">Sign In</a>
    <a href="#" class="block px-4 py-2 rounded-md bg-blue-600 text-white hover:bg-blue-700 text-center focus:outline-none focus:ring-2 focus:ring-blue-500 focus:ring-opacity-50 transition duration-200">Post a Job</a>
  </div>
</nav>