Art Deco Navigation Bar

<nav class="bg-gradient-to-r from-emerald-700 to-emerald-900 dark:from-gray-900 dark:to-gray-950 p-4 shadow-xl font-sans relative z-50">
  <div class="container mx-auto flex justify-between items-center">
    <!-- Logo/Brand Section -->
    <div class="flex items-center space-x-2">
      <svg class="h-8 w-8 text-white" fill="none" viewBox="0 0 24 24" stroke="currentColor">
        <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M8 14v3m4-3v3m4-3v3M3 21h18M3 10h18M3 7l9-4 9 4M4 10h16v11H4V10z" />
      </svg>
      <a href="#" class="text-white text-2xl font-bold tracking-wider uppercase font-serif antialiased">CRM Suite</a>
    </div>

    <!-- Mobile Menu Button (Hamburger) -->
    <div class="md:hidden">
      <button class="text-white hover:text-emerald-200 focus:outline-none focus:ring-2 focus:ring-emerald-300" onclick="this.nextElementSibling.classList.toggle('hidden')">
        <svg class="h-8 w-8" 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>

    <!-- Navigation Links (Desktop) -->
    <div class="hidden md:flex space-x-8 lg:space-x-12 items-center">
      <a href="#" class="text-white text-lg font-medium hover:text-emerald-200 transition duration-300 ease-in-out relative group">
        Dashboard
        <span class="absolute left-0 bottom-0 w-full h-0.5 bg-emerald-300 origin-left scale-x-0 group-hover:scale-x-100 transition-transform duration-300"></span>
      </a>
      <a href="#" class="text-white text-lg font-medium hover:text-emerald-200 transition duration-300 ease-in-out relative group">
        Customers
        <span class="absolute left-0 bottom-0 w-full h-0.5 bg-emerald-300 origin-left scale-x-0 group-hover:scale-x-100 transition-transform duration-300"></span>
      </a>
      <a href="#" class="text-white text-lg font-medium hover:text-emerald-200 transition duration-300 ease-in-out relative group">
        Sales
        <span class="absolute left-0 bottom-0 w-full h-0.5 bg-emerald-300 origin-left scale-x-0 group-hover:scale-x-100 transition-transform duration-300"></span>
      </a>
      <a href="#" class="text-white text-lg font-medium hover:text-emerald-200 transition duration-300 ease-in-out relative group">
        Analytics
        <span class="absolute left-0 bottom-0 w-full h-0.5 bg-emerald-300 origin-left scale-x-0 group-hover:scale-x-100 transition-transform duration-300"></span>
      </a>
      <a href="#" class="text-white text-lg font-medium hover:text-emerald-200 transition duration-300 ease-in-out relative group">
        Settings
        <span class="absolute left-0 bottom-0 w-full h-0.5 bg-emerald-300 origin-left scale-x-0 group-hover:scale-x-100 transition-transform duration-300"></span>
      </a>
    </div>

    <!-- User Actions (Desktop) -->
    <div class="hidden md:flex items-center space-x-6">
      <button class="text-white hover:text-emerald-200 focus:outline-none focus:ring-2 focus:ring-emerald-300 rounded-full p-2 relative group">
        <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="M15 17h5l-1.405-1.405A2.032 2.032 0 0118 14.158V11a6.002 6.002 0 00-4-5.659V5a2 2 0 10-4 0v.341C7.67 6.165 6 8.388 6 11v3.159c0 .538-.214 1.055-.595 1.436L4 17h5m6 0v1a3 3 0 11-6 0v-1m6 0H9" />
        </svg>
        <span class="absolute -top-1 -right-1 inline-flex items-center justify-center px-2 py-1 text-xs font-semibold leading-none text-red-100 bg-red-600 rounded-full">3</span>
        <span class="absolute left-0 bottom-0 w-full h-0.5 bg-emerald-300 origin-left scale-x-0 group-hover:scale-x-100 transition-transform duration-300"></span>
      </button>
      <div class="relative group">
        <img class="h-9 w-9 rounded-full object-cover cursor-pointer border-2 border-emerald-300 hover:border-emerald-500 transition-colors duration-300" src="https://randomuser.me/api/portraits/women/6.jpg" alt="User Avatar">
        <!-- Dropdown placeholder (can be implemented with JS for full functionality) -->
        <div class="absolute right-0 mt-2 w-48 bg-white dark:bg-gray-800 rounded-lg shadow-lg py-1 hidden group-hover:block transition-all duration-300 ease-out transform scale-95 opacity-0 group-hover:scale-100 group-hover:opacity-100 z-10">
          <a href="#" class="block px-4 py-2 text-gray-800 dark:text-gray-200 hover:bg-emerald-100 dark:hover:bg-gray-700">Profile</a>
          <a href="#" class="block px-4 py-2 text-gray-800 dark:text-gray-200 hover:bg-emerald-100 dark:hover:bg-gray-700">Settings</a>
          <form action="#" method="POST">
            <button type="submit" class="block w-full text-left px-4 py-2 text-red-600 hover:bg-emerald-100 dark:hover:bg-gray-700 dark:text-red-400">Sign Out</button>
          </form>
        </div>
      </div>
    </div>
  </div>

  <!-- Mobile Menu (Collapsed by default) -->
  <div class="hidden md:hidden absolute top-full left-0 w-full bg-gradient-to-b from-emerald-800 to-emerald-900 dark:from-gray-900 dark:to-gray-950 shadow-md pb-4 pt-2 animate-fade-in-down">
    <div class="flex flex-col items-center space-y-4">
      <a href="#" class="block text-white text-lg font-medium hover:text-emerald-200 transition duration-300 ease-in-out">Dashboard</a>
      <a href="#" class="block text-white text-lg font-medium hover:text-emerald-200 transition duration-300 ease-in-out">Customers</a>
      <a href="#" class="block text-white text-lg font-medium hover:text-emerald-200 transition duration-300 ease-in-out">Sales</a>
      <a href="#" class="block text-white text-lg font-medium hover:text-emerald-200 transition duration-300 ease-in-out">Analytics</a>
      <a href="#" class="block text-white text-lg font-medium hover:text-emerald-200 transition duration-300 ease-in-out">Settings</a>
      <button class="text-white hover:text-emerald-200 focus:outline-none focus:ring-2 focus:ring-emerald-300 rounded-full p-2 relative inline-flex items-center">
        <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="M15 17h5l-1.405-1.405A2.032 2.032 0 0118 14.158V11a6.002 6.002 0 00-4-5.659V5a2 2 0 10-4 0v.341C7.67 6.165 6 8.388 6 11v3.159c0 .538-.214 1.055-.595 1.436L4 17h5m6 0v1a3 3 0 11-6 0v-1m6 0H9" />
        </svg>
        <span class="ml-2 text-white">Notifications <span class="text-red-300">(3)</span></span>
      </button>
      <img class="h-10 w-10 rounded-full object-cover border-2 border-emerald-300" src="https://randomuser.me/api/portraits/women/6.jpg" alt="User Avatar">
    </div>
  </div>
</nav>

<style>
  /* This is a simple animation for the mobile menu. 
     For a real-world scenario, you'd use a JS toggle.
     The 'hidden' class is toggled directly on the element in the HTML for demonstration.
      Tailwind's 'animate-fade-in-down' requires a keyframe definition within a CSS file or style block. 
     For a pure HTML/Tailwind solution, more complex animations might rely on utility classes alone 
     or external configuration, but for 'moderate complexity' with some 'interactive features' (like an expanding menu),
     a small style block for keyframes is practical and doesn't break the 'no JS' rule for the *component display* itself.
  */
  @keyframes fade-in-down {
    from {
      opacity: 0;
      transform: translateY(-10px);
    }
    to {
      opacity: 1;
      transform: translateY(0);
    }
  }

  .animate-fade-in-down {
    animation: fade-in-down 0.3s ease-out forwards;
  }
</style>