2要素認証コンポーネント

<div class="flex items-center justify-center min-h-screen bg-gradient-to-br from-gray-200 via-gray-400 to-gray-600 dark:from-gray-800 dark:via-gray-900 dark:to-black p-4">
  <div class="relative w-full max-w-md bg-white dark:bg-gray-700 rounded-lg shadow-xl p-8">
    <div class="absolute top-0 left-0 w-full h-full border-4 border-black dark:border-gray-500 rounded-lg pointer-events-none"></div>
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      <h2 class="text-3xl font-bold text-center text-gray-800 dark:text-white mb-6 font-mono">Authenticate</h2>
      <div class="space-y-6">
        <div>
          <label for="code" class="block text-sm font-medium text-gray-700 dark:text-gray-300 font-mono">Enter 2FA Code</label>
          <div class="mt-1">
            <input type="text" name="code" id="code" class="block w-full px-4 py-3 rounded-md border-gray-300 shadow-sm focus:border-indigo-500 focus:ring-indigo-500 dark:bg-gray-600 dark:border-gray-500 dark:text-white dark:focus:border-indigo-600 dark:focus:ring-indigo-600 font-mono tracking-widest" placeholder="••••••">
          </div>
        </div>

        <div>
          <button type="submit" class="w-full flex justify-center py-3 px-4 border border-transparent rounded-md shadow-sm text-sm font-medium text-white bg-indigo-600 hover:bg-indigo-700 focus:outline-none focus:ring-2 focus:ring-offset-2 focus:ring-indigo-500 dark:bg-indigo-700 dark:hover:bg-indigo-800 dark:focus:ring-indigo-600 font-mono">
            Verify Code
          </button>
        </div>
      </div>
      <div class="mt-6 text-center">
        <p class="text-sm text-gray-600 dark:text-gray-400 font-mono">
          Need help? <a href="#" class="font-medium text-indigo-600 hover:text-indigo-500 dark:text-indigo-500 dark:hover:text-indigo-400">Resend Code</a>
        </p>
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