body {
            font-family: '΢ÈíÑźÚ', sans-serif;
            max-width: 800px;
            margin: 0 auto;
            padding: 20px;
            background-color: #f0f8ff;
        }

        .header {
            display: flex;
            justify-content: space-between;
            margin-bottom: 30px;
            padding: 15px;
            background-color: #4CAF50;
            color: white;
            border-radius: 10px;
            box-shadow: 0 2px 5px rgba(0,0,0,0.2);
        }

        .question-container {
            background: white;
            padding: 25px;
            border-radius: 10px;
            box-shadow: 0 2px 5px rgba(0,0,0,0.1);
            margin-bottom: 20px;
        }

        .options {
            display: grid;
            gap: 10px;
            margin: 20px 0;
        }

        button {
            padding: 12px;
            border: none;
            border-radius: 5px;
            background-color: #e7e7e7;
            cursor: pointer;
            transition: all 0.3s;
        }

        button:hover {
            background-color: #4CAF50;
        }

        .correct {
            background-color: #4CAF50 !important;
            color: white;
        }

        .wrong {
            background-color: #f44336 !important;
            color: white;
        }

        .explanation {
            padding: 15px;
            background-color: #e3f2fd;
            border-radius: 5px;
            margin-top: 20px;
            display: none;
        }

        .result {
            display: none;
            background: white;
            padding: 25px;
            border-radius: 10px;
            box-shadow: 0 2px 5px rgba(0,0,0,0.1);
        }

        .correct-bg {
            background-color: #e8f5e9 !important;
        }

        .wrong-bg {
            background-color: #ffebee !important;
        }

        .review-item {
            padding: 15px;
            margin: 15px 0;
            border-radius: 8px;
            transition: background-color 0.3s;
        }

        #nextBtn {
            margin-top: 20px;
            width: 100%;
            background-color: #2196F3;
            color: white;
        }

        #restart {
            background-color: #4CAF50;
            color: white;
            padding: 12px 24px;
            margin-top: 20px;
            width: 100%;
        }