.button-container {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 15px;
    justify-items: center;
    width: 100%;
}

.letter-button {
    background-color: #007bff;
    color: white;
    padding: 20px;
    font-size: calc(10px + 2vmin); /* Dynamisch je nach Bildschirmgröße */
    border: none;
    border-radius: 15px;
    cursor: pointer;
    transition: background-color 0.3s ease, transform 0.2s ease;
}

.letter-button:disabled {
    background-color: red;
    cursor: not-allowed;
}

.letter-button:hover:not(:disabled) {
    background-color: #0056b3;
    transform: scale(1.05);
}