body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    background-color: #f0f4f8;
}

#game-container {
    background-color: white;
    padding: 30px;
    border-radius: 12px;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
    text-align: center;
    max-width: 500px;
    width: 90%;
}

h1 {
    color: #1a237e;
    margin-bottom: 20px;
}

#score-area {
    font-size: 1.2em;
    font-weight: bold;
    color: #3f51b5;
    margin-bottom: 15px;
}

/* --- Flag Display --- */
#flag-display {
    border: 1px solid #ddd;
    border-radius: 8px;
    padding: 10px;
    margin-bottom: 20px;
    background-color: #eceff1;
}

#flag-image {
    width: 100%;
    max-width: 300px; /* Keep flag image size reasonable */
    height: auto;
    display: block;
    margin: 0 auto;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

/* --- Options Container --- */
#options-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
    margin-bottom: 20px;
}

.option-button {
    padding: 12px;
    font-size: 1em;
    cursor: pointer;
    background-color: #e3f2fd;
    color: #1a237e;
    border: 2px solid #90caf9;
    border-radius: 6px;
    transition: background-color 0.2s, transform 0.1s;
    font-weight: 600;
}

.option-button:hover:not(:disabled) {
    background-color: #bbdefb;
    transform: translateY(-2px);
}

.option-button:disabled {
    cursor: not-allowed;
    opacity: 0.7;
}

/* --- Feedback and Correct/Incorrect Styles --- */
#feedback-message {
    min-height: 1.5em; /* Reserve space to prevent layout jump */
    font-size: 1.2em;
    font-weight: bold;
    margin-bottom: 15px;
}

.correct {
    background-color: #4CAF50; /* Green for correct */
    color: white;
    border-color: #388e3c;
}

.incorrect {
    background-color: #f44336; /* Red for incorrect */
    color: white;
    border-color: #d32f2f;
}

/* --- Next Button --- */
#next-button {
    padding: 10px 20px;
    font-size: 1.1em;
    background-color: #00bcd4;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.2s;
}

#next-button:hover {
    background-color: #0097a7;
}