<?php
session_start();

// 問題の定義
$questions = [
  [
    "question" => "世界で一番高い山は？",
    "options" => ["富士山", "エベレスト", "キリマンジャロ"],
    "answer" => "エベレスト"
  ],
  [
    "question" => "光の速さはおよそ秒速何km？",
    "options" => ["30万km", "3万km", "300万km"],
    "answer" => "30万km"
  ],
  [
    "question" => "1年は何日？（うるう年を除く）",
    "options" => ["365日", "364日", "366日"],
    "answer" => "365日"
  ],
  [
    "question" => "日本で一番大きい湖は？",
    "options" => ["琵琶湖", "霞ヶ浦", "サロマ湖"],
    "answer" => "琵琶湖"
  ],
  [
    "question" => "太陽系で一番大きい惑星は？",
    "options" => ["木星", "土星", "地球"],
    "answer" => "木星"
  ]
];

// ランダムに1問選択
$randomIndex = array_rand($questions);
$selectedQuestion = $questions[$randomIndex];

// Sessionに問題と正解を保存
$_SESSION["current_question"] = $selectedQuestion["question"];
$_SESSION["current_answer"] = $selectedQuestion["answer"];
?>
<!DOCTYPE html>
<html lang="ja">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>クイズ</title>
  <style>
    body {
      font-family: sans-serif;
      max-width: 600px;
      margin: 50px auto;
      padding: 20px;
    }
    .quiz-container {
      background: white;
      padding: 30px;
      border-radius: 8px;
      border: 1px solid #ddd;
    }
    h1 {
      color: #333;
      margin-bottom: 30px;
    }
    .question {
      margin-bottom: 20px;
      font-size: 18px;
      font-weight: bold;
    }
    .options {
      margin-bottom: 20px;
    }
    .option {
      margin: 10px 0;
    }
    button {
      background-color: #4CAF50;
      color: white;
      padding: 12px 30px;
      border: none;
      border-radius: 4px;
      cursor: pointer;
      font-size: 16px;
    }
    button:hover {
      background-color: #45a049;
    }
  </style>
</head>
<body>
  <div class="quiz-container">
    <h1>ランダムクイズ</h1>
    
    <form method="post" action="answer.php">
      <div class="question">
        問題: <?php echo htmlspecialchars($selectedQuestion["question"]); ?>
      </div>
      
      <div class="options">
        <?php foreach ($selectedQuestion["options"] as $index => $option): ?>
          <div class="option">
            <label>
              <input type="radio" name="answer" value="<?php echo htmlspecialchars($option); ?>" <?php echo $index === 0 ? 'required' : ''; ?>>
              <?php echo htmlspecialchars($option); ?>
            </label>
          </div>
        <?php endforeach; ?>
      </div>
      
      <button type="submit">答えを送信</button>
    </form>
    
    <p style="margin-top: 20px; font-size: 14px; color: #666;">
      💡 開発者ツールでHTMLを見ても、正解は表示されていません。<br>
      正解はSessionに保存されています。
    </p>
  </div>
</body>
</html>
