* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            min-height: 100vh;
            display: flex;
            justify-content: center;
            align-items: center;
            padding: 20px;
        }

        .quiz-container {
            background: white;
            border-radius: 15px;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
            padding: 30px;
            max-width: 600px;
            width: 100%;
        }

        .quiz-header {
            text-align: center;
            margin-bottom: 30px;
        }

        .quiz-header h1 {
            color: #333;
            font-size: 2.5rem;
            margin-bottom: 10px;
        }

        .progress-bar {
            background: #e0e0e0;
            border-radius: 10px;
            height: 8px;
            margin-bottom: 20px;
            overflow: hidden;
        }

        .progress-fill {
            background: linear-gradient(90deg, #667eea, #764ba2);
            height: 100%;
            width: 0%;
            transition: width 0.3s ease;
        }

        .question-counter {
            text-align: center;
            color: #666;
            margin-bottom: 20px;
            font-size: 1.1rem;
        }

        .question-area {
            margin-bottom: 30px;
        }

        .question-text {
            font-size: 1.3rem;
            color: #333;
            margin-bottom: 25px;
            line-height: 1.5;
        }

        .answer-options {
            display: flex;
            flex-direction: column;
            gap: 15px;
        }

        .option-button {
            background: #f8f9fa;
            border: 2px solid #e9ecef;
            border-radius: 10px;
            padding: 15px 20px;
            font-size: 1.1rem;
            cursor: pointer;
            transition: all 0.3s ease;
            text-align: left;
        }

        .option-button:hover {
            background: #e9ecef;
            border-color: #667eea;
            transform: translateY(-2px);
        }

        .option-button.selected {
            background: #667eea;
            color: white;
            border-color: #667eea;
        }

        .option-button.correct {
            background: #28a745;
            color: white;
            border-color: #28a745;
        }

        .option-button.incorrect {
            background: #dc3545;
            color: white;
            border-color: #dc3545;
        }

        .option-button:disabled {
            cursor: not-allowed;
        }

        .feedback {
            margin: 20px 0;
            padding: 15px;
            border-radius: 8px;
            font-weight: bold;
            text-align: center;
            opacity: 0;
            transition: opacity 0.3s ease;
        }

        .feedback.show {
            opacity: 1;
        }

        .feedback.correct {
            background: #d4edda;
            color: #155724;
            border: 1px solid #c3e6cb;
        }

        .feedback.incorrect {
            background: #f8d7da;
            color: #721c24;
            border: 1px solid #f5c6cb;
        }

        .score-display {
            text-align: center;
            font-size: 1.2rem;
            color: #333;
            margin-bottom: 20px;
        }

        .next-button {
            background: linear-gradient(135deg, #667eea, #764ba2);
            color: white;
            border: none;
            border-radius: 8px;
            padding: 12px 30px;
            font-size: 1.1rem;
            cursor: pointer;
            transition: transform 0.2s ease;
            display: block;
            margin: 20px auto 0;
        }

        .next-button:hover {
            transform: translateY(-2px);
        }

        .next-button:disabled {
            background: #ccc;
            cursor: not-allowed;
            transform: none;
        }

        .final-score {
            text-align: center;
            padding: 30px;
        }

        .final-score h2 {
            color: #333;
            font-size: 2rem;
            margin-bottom: 20px;
        }

        .score-circle {
            width: 150px;
            height: 150px;
            border-radius: 50%;
            background: linear-gradient(135deg, #667eea, #764ba2);
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 20px auto;
            color: white;
            font-size: 2rem;
            font-weight: bold;
        }

        .restart-button {
            background: #28a745;
            color: white;
            border: none;
            border-radius: 8px;
            padding: 12px 30px;
            font-size: 1.1rem;
            cursor: pointer;
            margin-top: 20px;
        }

        .restart-button:hover {
            background: #218838;
        }

        @media (max-width: 600px) {
            .quiz-container {
                padding: 20px;
            }
            
            .quiz-header h1 {
                font-size: 2rem;
            }
            
            .question-text {
                font-size: 1.1rem;
            }
        }