문제 6: 가격 표 ⭐⭐

<div class="flex gap-4">
  <!-- Basic -->
  <div class="bg-white rounded-lg shadow-lg p-8 flex-1">
    <div class="flex flex-col items-center gap-4">
      <h3 class="text-2xl font-bold">Basic</h3>
      <div class="text-4xl font-bold text-blue-600">$9</div>
      <button class="bg-blue-500 text-white w-full">선택</button>
    </div>
  </div>
  <!-- Pro (강조) -->
  <div class="bg-blue-500 text-white shadow-xl">...</div>
  <!-- Enterprise -->
  <div class="bg-white">...</div>
</div>