/* Global styles */
        body {
            font-family: 'Arial', sans-serif;
            background-color: #f4f4f4;
            color: #333;
            margin: 0;
            padding: 0;
            line-height: 1.6;
        }

        h2 {
            text-align: center;
            margin: 20px 0;
            color: #2c3e50;
        }

        /* Container */
        #quiz-container {
            max-width: 800px;
            margin: 20px auto;
            background: #fff;
            padding: 20px;
            border-radius: 8px;
            box-shadow: 0 0 15px rgba(0, 0, 0, 0.1);
        }

        /* Labels and select boxes */
        label {
            font-weight: bold;
            display: block;
            margin-bottom: 10px;
            margin-top: 20px;
            color: #34495e;
        }

        select {
            width: 100%;
            padding: 10px;
            margin-bottom: 20px;
            border: 1px solid #ccc;
            border-radius: 4px;
            background-color: #ecf0f1;
            font-size: 16px;
        }

        /* Question and answer styling */
        p {
            margin: 10px 0;
            font-size: 16px;
        }

        strong {
            color: #2c3e50;
        }

        ul {
            padding: 0;
            list-style: none;
        }

        li {
            margin: 10px 0;
            display: flex;
            align-items: center;
        }

        .option-letter {
            font-weight: bold;
            margin-right: 10px;
        }

        li button {
            flex-grow: 1;
            background-color: #3498db;
            color: white;
            border: none;
            padding: 10px;
            border-radius: 4px;
            cursor: pointer;
            font-size: 16px;
            transition: background-color 0.3s ease;
        }

        li button:hover {
            background-color: #2980b9;
        }

        .correcta {
            background-color: transparent;
            padding: 10px;
            border-radius: 4px;
            color: green;
        }

        .incorrecta {
            background-color: transparent;
            padding: 10px;
            border-radius: 4px;
            color: red;
        }

        .solution-button {
            width: 100%;
            background-color: #e67e22;
            color: white;
            border: none;
            padding: 10px;
            border-radius: 4px;
            cursor: pointer;
            font-size: 16px;
            transition: background-color 0.3s ease;
            margin-top: 20px;
        }

        .solution-button:hover {
            background-color: #d35400;
        }

        .ocult {
            display: none;
        }

        .visible {
            display: block;
        }

        /* Responsive design */
        @media (max-width: 768px) {
            #quiz-container {
                padding: 15px;
            }

            li button,
            .solution-button {
                font-size: 14px;
                padding: 8px;
            }

            select {
                font-size: 14px;
                padding: 8px;
            }
        }

        @media (max-width: 480px) {
            h2 {
                font-size: 24px;
            }

            li button,
            .solution-button {
                font-size: 12px;
                padding: 6px;
            }

            select {
                font-size: 12px;
                padding: 6px;
            }

            #quiz-container {
                padding: 10px;
            }
        }