body {
    font-family: Arial, sans-serif;
    background-color: #e6f4e6;
    display: flex;
    justify-content: center;
    margin: 0;
    padding: 20px;
}

.container {
    max-width: 600px;
    width: 100%;
    text-align: center;
}

.frog-image {
    margin-bottom: 20px;
}

.frog-image img {
    max-width: 150px; /* Adjust size as needed */
    height: auto;
}

h1 {
    color: #2e7d32;
}

h3 {
    color: #388e3c;
}

.how-to-play, .progress, .letters-section {
    background-color: white;
    border: 1px solid #c8e6c9;
    border-radius: 10px;
    padding: 20px;
    margin: 10px 0;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

.how-to-play h2, .letters-section h3 {
    color: #2e7d32;
}

.japanese {
    font-size: 0.9em;
    color: #555;
    margin-top: 5px;
}

.progress {
    text-align: center; /* Center the content */
}

.progress p {
    margin-bottom: 10px; /* Add space between "Progress:" and the bar */
}

.progress-bar {
    width: 100%;
    background-color: #e0e0e0;
    height: 10px;
    border-radius: 5px;
    margin: 0 auto; /* Center the bar */
}

.progress-fill {
    height: 100%;
    border-radius: 5px;
    width: 0%;
    transition: width 0.3s ease;
}

.progress-fill.green {
    background-color: #4caf50; /* Green for Round 1 */
}

.progress-fill.blue {
    background-color: #2196f3; /* Blue for Round 2 */
}

.progress-fill.gold {
    background-color: #ffd700; /* Gold for Round 3 */
}

.letters-container {
    display: flex;
    justify-content: center;
    gap: 10px;
    flex-wrap: wrap;
}

.letter-btn {
    background-color: #e8f5e9;
    border: 2px solid #c8e6c9;
    border-radius: 10px;
    padding: 20px;
    font-size: 24px;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

.letter-btn:hover {
    background-color: #c8e6c9;
}

.letter-btn.correct {
    background-color: #4caf50;
    color: white;
}

.letter-btn.incorrect {
    background-color: #ef5350;
    color: white;
}