main {
    text-align: center;
    margin: 50px auto;
    padding: 20px;
    background-color: rgb(241, 241, 241);
    border-radius: 8px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.215);
    width: 80%;
    max-width: 600px;
}

label {
    font-size: 18px;
}

select {
    padding: 8px;
    margin: 10px 0;
    font-size: 16px;
}

button {
    padding: 10px 20px;
    font-size: 18px;
    border: none;
    background: #4CAF50;
    color: white;
    cursor: pointer;
    border-radius: 5px;
}

button:hover {
    background: #45a049;
}

.letter-box {
    font-size: 48px;
    font-weight: bold;
    margin-top: 20px;
    padding: 15px;
    display: inline-block;
    border: 2px solid #333;
    border-radius: 5px;
    background: #fff;
    width: 100px;
    text-align: center;
}