.quiz-container { max-width: 800px; margin: 0 auto; padding: 20px; }
        .quiz-header { text-align: center; margin-bottom: 40px; }
        .quiz-header h1 { font-size: 2.5rem; color: #1e3a5f; margin-bottom: 10px; }
        .quiz-header p { color: #666; font-size: 1.1rem; }
        .progress-bar { background: #e0e0e0; border-radius: 20px; height: 12px; margin-bottom: 30px; overflow: hidden; }
        .progress-fill { background: linear-gradient(90deg, #10b981, #059669); height: 100%; border-radius: 20px; transition: width 0.4s ease; }
        .progress-text { text-align: center; font-size: 0.9rem; color: #666; margin-bottom: 10px; }
        .question-card { background: white; border-radius: 16px; padding: 30px; box-shadow: 0 4px 20px rgba(0,0,0,0.1); margin-bottom: 20px; }
        .question-number { display: inline-block; background: linear-gradient(135deg, #10b981, #059669); color: white; padding: 8px 16px; border-radius: 20px; font-size: 0.85rem; font-weight: 600; margin-bottom: 15px; }
        .question-text { font-size: 1.3rem; color: #1e3a5f; font-weight: 600; margin-bottom: 25px; line-height: 1.5; }
        .options-list { display: flex; flex-direction: column; gap: 12px; }
        .option-btn { background: #f8fafc; border: 2px solid #e2e8f0; border-radius: 12px; padding: 16px 20px; text-align: left; font-size: 1rem; cursor: pointer; transition: all 0.3s ease; display: flex; align-items: center; gap: 12px; }
        .option-btn:hover { border-color: #10b981; background: #f0fdf4; transform: translateX(5px); }
        .option-btn.selected { border-color: #10b981; background: #d1fae5; }
        .option-btn.correct { border-color: #10b981; background: #d1fae5; }
        .option-btn.incorrect { border-color: #ef4444; background: #fee2e2; }
        .option-letter { width: 32px; height: 32px; background: #e2e8f0; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-weight: 600; color: #64748b; flex-shrink: 0; }
        .option-btn.selected .option-letter { background: #10b981; color: white; }
        .option-btn.correct .option-letter { background: #10b981; color: white; }
        .option-btn.incorrect .option-letter { background: #ef4444; color: white; }
        .nav-buttons { display: flex; justify-content: space-between; margin-top: 25px; gap: 15px; }
        .btn-next { background: linear-gradient(135deg, #10b981, #059669); color: white; border: none; padding: 14px 35px; border-radius: 30px; font-size: 1rem; font-weight: 600; cursor: pointer; transition: all 0.3s ease; flex: 1; max-width: 200px; margin-left: auto; }
        .btn-next:hover { transform: translateY(-2px); box-shadow: 0 6px 20px rgba(16, 185, 129, 0.4); }
        .btn-next:disabled { background: #cbd5e1; cursor: not-allowed; transform: none; box-shadow: none; }
        /* Results */
        .results-container { display: none; text-align: center; }
        .results-card { background: white; border-radius: 20px; padding: 40px; box-shadow: 0 10px 40px rgba(0,0,0,0.15); }
        .results-icon { font-size: 80px; margin-bottom: 20px; }
        .results-level { font-size: 3rem; font-weight: 800; background: linear-gradient(135deg, #10b981, #059669); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; margin-bottom: 10px; }
        .results-title { font-size: 1.5rem; color: #1e3a5f; margin-bottom: 20px; }
        .results-score { font-size: 1.1rem; color: #666; margin-bottom: 30px; }
        .results-description { background: #f0fdf4; border-radius: 12px; padding: 20px; margin-bottom: 30px; text-align: left; }
        .results-description h4 { color: #059669; margin-bottom: 10px; }
        .results-description p { color: #374151; line-height: 1.6; margin: 0; }
        .btn-cta { display: inline-block; background: linear-gradient(135deg, #f59e0b, #d97706); color: white; padding: 16px 40px; border-radius: 30px; font-size: 1.1rem; font-weight: 600; text-decoration: none; transition: all 0.3s ease; }
        .btn-cta:hover { transform: translateY(-3px); box-shadow: 0 8px 25px rgba(245, 158, 11, 0.4); }
        .btn-restart { display: inline-block; margin-top: 15px; color: #059669; text-decoration: underline; cursor: pointer; font-size: 0.95rem; }
        /* Start screen */
        .start-screen { text-align: center; padding: 40px 20px; }
        .start-icon { font-size: 100px; margin-bottom: 20px; }
        .start-title { font-size: 2rem; color: #1e3a5f; margin-bottom: 15px; }
        .start-description { color: #666; font-size: 1.1rem; margin-bottom: 30px; max-width: 500px; margin-left: auto; margin-right: auto; }
        .start-features { display: flex; justify-content: center; gap: 30px; margin-bottom: 35px; flex-wrap: wrap; }
        .start-feature { display: flex; align-items: center; gap: 8px; color: #374151; }
        .start-feature span { color: #10b981; font-size: 1.2rem; }
        .btn-start { background: linear-gradient(135deg, #10b981, #059669); color: white; border: none; padding: 18px 50px; border-radius: 35px; font-size: 1.2rem; font-weight: 700; cursor: pointer; transition: all 0.3s ease; }
        .btn-start:hover { transform: translateY(-3px); box-shadow: 0 10px 30px rgba(16, 185, 129, 0.4); }
        @media (max-width: 600px) {
            .quiz-header h1 { font-size: 1.8rem; }
            .question-text { font-size: 1.1rem; }
            .start-features { flex-direction: column; gap: 15px; }
        }