body {
    font-family: 'Arial', sans-serif;
    background-color: #f0f8ff;
    text-align: center;
    margin: 0;
    padding: 0;
}

#message-container {
    width: 350px;
    margin: 20px auto;
    font-size: 1rem;
    color: #333;
    padding: 10px;
    background-color: #e8f5e9;
    border: 2px solid #2e7d32;
    border-radius: 5px;
}

#game-container {
    display: none;
    width: 350px;
    margin: 20px auto;
}

#question {
    font-size: 1.5rem;
    color: #2c3e50;
    margin-bottom: 20px;
}

#button-container {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 10px;
}

.answer-card {
    font-size: 1rem;
    width: 60px;
    height: 60px;
    background-color: #ffffff;
    border: 2px solid #3498db;
    border-radius: 5px;
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    transition: background-color 0.3s, transform 0.2s;
}

.answer-card:hover {
    background-color: #e3f2fd;
    transform: scale(1.1);
}

#start-button {
    font-size: 1.2rem;
    padding: 10px 30px;
    background-color: #27ae60;
    color: #fff;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s;
}

#start-button:hover {
    background-color: #1e8449;
}

.success-animation {
    animation: success-flash 1s;
}

@keyframes success-flash {
    0%, 100% {
        background-color: #f0f8ff;
    }
    50% {
        background-color: #ffeb3b;
    }
}

.error-animation {
    animation: error-shake 0.5s;
}

@keyframes error-shake {
    0%, 100% {
        transform: translateX(0);
    }
    25% {
        transform: translateX(-10px);
    }
    75% {
        transform: translateX(10px);
    }
}