Mega Menu Component - Dark Mode UI (Finance/Banking)

<nav class="bg-gray-900 text-gray-200 p-4 dark:bg-gray-950 dark:text-gray-100 relative">
  <div class="container mx-auto flex justify-between items-center">
    <a href="#" class="text-xl font-bold text-blue-400 hover:text-blue-300 transition-colors duration-300">FinSecure Bank</a>
    <div class="hidden md:flex space-x-6">
      <a href="#" class="hover:text-blue-400 transition-colors duration-300">Personal</a>
      <a href="#" class="hover:text-blue-400 transition-colors duration-300">Business</a>
      <div class="group relative">
        <button class="flex items-center hover:text-blue-400 transition-colors duration-300 focus:outline-none">Services <svg class="w-4 h-4 ml-1 transform group-hover:rotate-180 transition-transform duration-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="M19 9l-7 7-7-7"></path></svg></button>
        <div class="absolute hidden group-hover:block w-full left-1/2 -ml-[calc(50vw-50%)] xl:left-0 xl:ml-0 xl:w-screen xl:max-w-7xl pt-4 z-50">
          <div class="bg-gray-800 dark:bg-gray-900 rounded-lg shadow-xl p-8 grid grid-cols-1 md:grid-cols-3 gap-8 ring-1 ring-gray-700 dark:ring-gray-800">
            <div>
              <h3 class="font-semibold text-lg text-blue-400 mb-4">Popular Links</h3>
              <ul class="space-y-2 text-sm">
                <li><a href="#" class="hover:text-blue-300 dark:hover:text-blue-400 transition-colors duration-200">Online Banking Login</a></li>
                <li><a href="#" class="hover:text-blue-300 dark:hover:text-blue-400 transition-colors duration-200">Mortgage Rates</a></li>
                <li><a href="#" class="hover:text-blue-300 dark:hover:text-blue-400 transition-colors duration-200">Credit Card Offers</a></li>
                <li><a href="#" class="hover:text-blue-300 dark:hover:text-blue-400 transition-colors duration-200">Investment Portfolios</a></li>
                <li><a href="#" class="hover:text-blue-300 dark:hover:text-blue-400 transition-colors duration-200">ATM Locator</a></li>
              </ul>
            </div>
            <div>
              <h3 class="font-semibold text-lg text-blue-400 mb-4">Account Services</h3>
              <ul class="space-y-2 text-sm">
                <li><a href="#" class="hover:text-blue-300 dark:hover:text-blue-400 transition-colors duration-200">Open New Account</a></li>
                <li><a href="#" class="hover:text-blue-300 dark:hover:text-blue-400 transition-colors duration-200">Apply for Loan</a></li>
                <li><a href="#" class="hover:text-blue-300 dark:hover:text-blue-400 transition-colors duration-200">Bill Pay & Transfers</a></li>
                <li><a href="#" class="hover:text-blue-300 dark:hover:text-blue-400 transition-colors duration-200">Statements & Documents</a></li>
                <li><a href="#" class="hover:text-blue-300 dark:hover:text-blue-400 transition-colors duration-200">Fraud Protection</a></li>
              </ul>
            </div>
            <div>
              <h3 class="font-semibold text-lg text-blue-400 mb-4">Quick Access</h3>
              <img src="https://picsum.photos/300/200?random=1" alt="Banking illustration" class="rounded-lg mb-4 shadow-md" loading="lazy">
              <p class="text-sm text-gray-400 dark:text-gray-400 mb-2">Need assistance or have a question? Contact our 24/7 support team.</p>
              <a href="#" class="inline-flex items-center text-blue-400 hover:text-blue-300 dark:hover:text-blue-400 transition-colors duration-200 text-sm font-medium">
                Get Support
                <svg class="w-4 h-4 ml-1" 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="M9 5l7 7-7 7"></path></svg>
              </a>
            </div>
          </div>
        </div>
      </div>
      <a href="#" class="hover:text-blue-400 transition-colors duration-300">About Us</a>
      <a href="#" class="hover:text-blue-400 transition-colors duration-300">Contact</a>
    </div>
    <div class="md:hidden">
      <button class="text-gray-200 hover:text-blue-400 focus:outline-none">
        <svg class="w-6 h-6" 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>
</nav>