body {
            font-family: 'Inter', sans-serif;
            background-color: #f0f4f8;
            display: flex;
            justify-content: center;
            align-items: center;
            min-height: 100vh;
            padding: 1rem;
            overflow-x: hidden;
        }
        .quiz-container {
            background-color: #ffffff;
            border-radius: 1.5rem;
            box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
            padding: 2rem;
            width: 100%;
            max-width: 600px;
            text-align: center;
            transition: all 0.5s ease-in-out;
            opacity: 0;
            transform: translateY(20px);
        }
        .quiz-container.show {
            opacity: 1;
            transform: translateY(0);
        }
        .option-button {
            background-color: #e2e8f0;
            color: #334155;
            padding: 0.75rem 1.25rem;
            border-radius: 0.75rem;
            margin-bottom: 0.75rem;
            cursor: pointer;
            transition: background-color 0.3s ease, transform 0.1s ease;
            text-align: left;
            width: 100%;
            font-size: 1.1rem;
            border: 1px solid transparent; /* Default border */
        }
        .option-button:hover:not(.disabled) {
            background-color: #cbd5e1;
            transform: translateY(-2px);
        }
        .option-button.correct {
            background-color: #d1fae5;
            color: #065f46;
            border-color: #34d399;
        }
        .option-button.incorrect {
            background-color: #fee2e2;
            color: #991b1b;
            border-color: #ef4444;
        }
        .option-button.disabled {
            cursor: not-allowed;
            opacity: 0.7;
        }
        .progress-bar-container {
            background-color: #e2e8f0;
            border-radius: 9999px;
            height: 8px;
            margin-top: 1.5rem;
            overflow: hidden;
        }
        .progress-bar {
            background-color: #3b82f6;
            height: 100%;
            width: 0%;
            border-radius: 9999px;
            transition: width 0.5s ease-in-out;
        }
        .score-card {
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            padding: 2rem;
            background-color: #f8fafc;
            border-radius: 1.5rem;
            margin-top: 2rem;
            box-shadow: inset 0 2px 4px 0 rgba(0, 0, 0, 0.06);
            opacity: 0;
            transform: scale(0.9);
            transition: all 0.5s ease-in-out;
        }
        .score-card.show {
            opacity: 1;
            transform: scale(1);
        }
        .score-icon {
            width: 80px;
            height: 80px;
            margin-bottom: 1.5rem;
        }
        .start-button {
            background-color: #4f46e5;
            color: white;
            padding: 1rem 2rem;
            border-radius: 0.75rem;
            font-size: 1.25rem;
            font-weight: 600;
            cursor: pointer;
            transition: background-color 0.3s ease, transform 0.1s ease;
            box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
        }
        .start-button:hover {
            background-color: #4338ca;
            transform: translateY(-2px);
        }
        .start-button:active {
            transform: translateY(0);
            box-shadow: none;
        }
        .social-share-buttons {
            display: flex;
            justify-content: center;
            gap: 1rem;
            margin-top: 2rem;
        }
        .social-share-buttons button {
            background-color: #6b7280;
            color: white;
            padding: 0.75rem 1rem;
            border-radius: 0.5rem;
            font-size: 1rem;
            display: flex;
            align-items: center;
            gap: 0.5rem;
            transition: background-color 0.3s ease;
        }
        .social-share-buttons button:hover {
            background-color: #4b5563;
        }
        .social-share-buttons .whatsapp { background-color: #25D366; }
        .social-share-buttons .whatsapp:hover { background-color: #1DA851; }
        .social-share-buttons .facebook { background-color: #1877F2; }
        .social-share-buttons .facebook:hover { background-color: #145CB3; }
        .social-share-buttons .pinterest { background-color: #E60023; }
        .social-share-buttons .pinterest:hover { background-color: #B3001C; }
        .social-share-buttons .teams { background-color: #6264A7; }
        .social-share-buttons .teams:hover { background-color: #4A4C84; }

        .challenge-info {
            background-color: #e0f2fe;
            border: 1px solid #90cdf4;
            color: #2c5282;
            padding: 1rem;
            border-radius: 0.75rem;
            margin-bottom: 1.5rem;
            font-size: 1.1rem;
            font-weight: 600;
        }
        .input-field {
            width: 100%;
            padding: 0.75rem;
            margin-bottom: 1.5rem;
            border: 1px solid #cbd5e1;
            border-radius: 0.75rem;
            font-size: 1.1rem;
            text-align: center;
        }

        /* Responsive adjustments */
        @media (max-width: 640px) {
            .quiz-container {
                padding: 1.5rem;
            }
            .option-button {
                font-size: 1rem;
                padding: 0.6rem 1rem;
            }
            .score-icon {
                width: 60px;
                height: 60px;
            }
            .start-button {
                padding: 0.8rem 1.5rem;
                font-size: 1.1rem;
            }
            .social-share-buttons {
                flex-wrap: wrap;
            }
            .social-share-buttons button {
                width: calc(50% - 0.5rem); /* Two buttons per row */
                justify-content: center;
            }
        }