* {box-sizing: border-box;
        }

    body {
        font-family: 'Arial', sans-serif;
        max-width: 100%;
        margin: 0;
        padding: 10px;
        background-color: #f8f9fa;
        font-size: 16px;
        line-height: 1.5;
        }

        .quiz-container {
            background: white;
            border-radius: 8px;
            box-shadow: 0 2px 8px rgba(0,0,0,0.1);
            padding: 15px;
            margin: 0 auto;
            max-width: 800px;
        }

        h2 {
            text-align: center;
            color: #1a73e8;
            margin-bottom: 20px;
            font-size: 1.5em;
        }

        .data-table {
            width: 100%;
            border-collapse: collapse;
            margin: 15px 0;
            font-size: 14px;
            overflow-x: auto;
            display: block;
            white-space: nowrap;
        }

        .data-table th, .data-table td {
            border: 1px solid #dadce0;
            padding: 8px;
            text-align: center;
            min-width: 80px;
        }

        .data-table th {
            background-color: #f8f9fa;
            font-weight: bold;
            position: sticky;
            top: 0;
        }

        .data-table tr:nth-child(even) {
            background-color: #f8f9fa;
        }

        .question {
            margin-bottom: 20px;
            padding: 15px;
            border: 1px solid #dadce0;
            border-radius: 8px;
            display: none;
        }

        .question.active {
            display: block;
        }

        .question h3 {
            color: #1a73e8;
            margin-bottom: 15px;
            font-size: 1.2em;
        }

        .question p {
            margin-bottom: 15px;
            color: #333;
            word-wrap: break-word;
        }

        .options {
            display: flex;
            flex-direction: column;
            gap: 12px;
            margin-top: 15px;
        }

        .option {
            padding: 15px;
            border: 2px solid #dadce0;
            border-radius: 8px;
            cursor: pointer;
            transition: all 0.3s ease;
            background: white;
            word-wrap: break-word;
            min-height: 50px;
            display: flex;
            align-items: center;
        }

        .option img {
            max-width: 100%;
            height: auto;
            display: block;
            margin: 0 auto;
            border-radius: 4px;
        }

        .option:hover {
            background-color: #f1f3f4;
            transform: translateY(-1px);
        }

        .option:active {
            transform: translateY(0);
        }

        .option.selected {
            background-color: #e8f0fe;
            border-color: #1a73e8;
            box-shadow: 0 2px 8px rgba(26, 115, 232, 0.2);
        }
        
        button {
            background-color: #1a73e8;
            color: white;
            border: none;
            padding: 12px 24px;
            border-radius: 8px;
            cursor: pointer;
            font-size: 16px;
            font-weight: 500;
            transition: background-color 0.3s ease;
            min-height: 48px;
        }

        button:hover {
            background-color: #1557b0;
        }

        button:active {
            background-color: #0f4c75;
        }

        .navigation {
            display: flex;
            justify-content: space-between;
            margin-top: 20px;
            gap: 10px;
        }

        .navigation button {
            flex: 1;
            max-width: 150px;
        }

        .results {
            margin-top: 20px;
        }

        .correct {
            background-color: white;
            color: black;
            padding: 15px;
            border-radius: 8px;
            margin: 10px 0;
            border-left: 4px solid #34a853;
            position: relative;
            padding-left: 45px;
        }

        .incorrect {
            background-color: white;
            color: black;
            padding: 15px;
            border-radius: 8px;
            margin: 10px 0;
            border-left: 4px solid #ea4335;
            position: relative;
            padding-left: 45px;
        }

        .excluded {
            background-color: white;
            color: black;
            padding: 15px;
            border-radius: 8px;
            margin: 10px 0;
            border-left: 4px solid #fbbc04;
            position: relative;
            padding-left: 45px;
        }

        .correct::before {
            content: "✓";
            position: absolute;
            left: 15px;
            top: 50%;
            transform: translateY(-50%);
            color: #34a853;
            font-size: 20px;
            font-weight: bold;
        }

        .incorrect::before {
            content: "✗";
            position: absolute;
            left: 15px;
            top: 50%;
            transform: translateY(-50%);
            color: #ea4335;
            font-size: 20px;
            font-weight: bold;
        }

        .excluded::before {
            content: "⊘";
            position: absolute;
            left: 15px;
            top: 50%;
            transform: translateY(-50%);
            color: #fbbc04;
            font-size: 20px;
            font-weight: bold;
        }

        .progress-bar {
            width: 100%;
            height: 6px;
            background-color: #dadce0;
            margin-bottom: 20px;
            border-radius: 3px;
            overflow: hidden;
        }

        .progress {
            height: 100%;
            background-color: #1a73e8;
            transition: width 0.3s ease;
        }

        .timer {
            position: fixed;
            top: 10px;
            right: 10px;
            background: #1a73e8;
            color: white;
            padding: 8px 16px;
            border-radius: 20px;
            font-size: 14px;
            font-weight: 500;
            box-shadow: 0 2px 8px rgba(0,0,0,0.2);
            z-index: 1000;
        }

        .timer.warning {
            background: #ea4335;
            animation: pulse 1s infinite;
        }

        @keyframes pulse {
            0%, 100% { opacity: 1; }
            50% { opacity: 0.7; }
        }

        .score-display {
            background: linear-gradient(135deg, #1a73e8, #4285f4);
            color: white;
            padding: 20px;
            border-radius: 12px;
            text-align: center;
            margin: 20px 0;
            box-shadow: 0 4px 12px rgba(26, 115, 232, 0.3);
        }

        .score-display h3 {
            margin: 0 0 10px 0;
            font-size: 1.5em;
        }

        .score-display .score-number {
            font-size: 2.5em;
            font-weight: bold;
            margin: 10px 0;
        }

        .score-display .score-description {
            font-size: 1.1em;
            opacity: 0.9;
        }

        .excluded-questions {
            background-color: #fff3cd;
            border: 2px solid #fbbc04;
            border-radius: 8px;
            padding: 15px;
            margin: 20px 0;
        }

        .excluded-questions h4 {
            color: #b06000;
            margin-top: 0;
        }

        /* Responsive adjustments */
        @media (max-width: 768px) {
            body {
                padding: 5px;
                font-size: 15px;
            }

            .quiz-container {
                padding: 12px;
            }

            .timer {
                top: 5px;
                right: 5px;
                padding: 6px 12px;
                font-size: 13px;
            }

            .data-table {
                font-size: 12px;
                display: block;
                overflow-x: auto;
                white-space: nowrap;
            }

            .data-table th, .data-table td {
                padding: 6px;
                min-width: 60px;
            }

            .option {
                padding: 12px;
                min-height: 44px;
            }

            button {
                padding: 10px 20px;
                font-size: 15px;
                min-height: 44px;
            }

            .score-display .score-number {
                font-size: 2em;
            }

            h2 {
                font-size: 1.3em;
            }

            .question h3 {
                font-size: 1.1em;
            }
        }

        @media (max-width: 480px) {
            body {
                font-size: 14px;
            }

            .quiz-container {
                padding: 10px;
            }

            .data-table {
                font-size: 11px;
            }

            .data-table th, .data-table td {
                padding: 4px;
                min-width: 50px;
            }

            .navigation {
                flex-direction: column;
            }

            .navigation button {
                max-width: none;
            }

            .score-display .score-number {
                font-size: 1.8em;
            }
        }
            .fraction {
                display: inline-block;
                vertical-align: middle;
                margin: 0 0.1em;
                text-align: center;
                font-family: 'Times New Roman', serif;
        }

            .fraction .frac-top, .fraction .frac-bottom {
                display: block;
                font-size: 0.8em;
                line-height: 1;
        }

            .fraction .frac-top {
                border-bottom: 1px solid #000;
                padding-bottom: 0.1em;
                margin-bottom: 0.1em;
        }

            .fraction .frac-bottom {
                padding-top: 0.1em;
        }

        /* Variante más elegante con barra diagonal */
            .fraction-simple {
                white-space: nowrap;
                font-family: 'Times New Roman', serif;
        }

        /* Estilos responsive para dispositivos móviles */
            @media (max-width: 768px) {
                .fraction {
                    margin: 0 0.05em;
                }
    
                .fraction .frac-top, .fraction .frac-bottom {
                    font-size: 0.75em;
                }
            }
            .math-expr {
                font-family: 'Times New Roman', serif;
                font-size: 1.1em;
            }

            .fraction {
                display: inline-block;
                vertical-align: middle;
                margin: 0 0.2em;
                text-align: center;
                position: relative;
            }

            .fraction .num {
                display: block;
                border-bottom: 1px solid #333;
                padding-bottom: 0.1em;
                margin-bottom: 0.1em;
                line-height: 1;
                font-size: 0.9em;
            }

            .fraction .den {
                display: block;
                padding-top: 0.1em;
                line-height: 1;
                font-size: 0.9em;
            }

            .overline {
                text-decoration: overline;
            }

            sup {
                font-size: 0.75em;
                vertical-align: super;
            }

            sub {
                font-size: 0.75em;
                vertical-align: sub;
            }