ficulty-dot"></span>
                </div>
                <button class="start-quiz-btn" data-level="初学者">开始测验</button>
            </div>
            
            <div class="level-card" data-level="进阶者">
                <div class="level-icon">🌿</div>
                <h3>进阶者</h3>
                <p>深入垃圾处理知识</p>
                <div class="level-difficulty">
                    <span class="difficulty-dot active"></span>
                    <span class="diffic