body {
    font-family: Arial, sans-serif;
    background-color: #f4f4f4;
    margin: 0;
    padding: 20px;
}

h1 {
    text-align: center;
    color: #333;
}

#sudoku-container {
    display: flex;
    flex-direction: column;
    align-items: center;
}

table {
    border-collapse: collapse;
}

td {
    border: 1px solid #ccc;
}

#sudoku-input {
    display: grid;
    grid-template-columns: repeat(9, 40px);
    gap: 5px;
    margin-bottom: 20px;
}

.sudoku-input {
    width: 40px;
    height: 40px;
    text-align: center;
    font-size: 18px;
    border: none;
    outline: none;
}

input[type="number"] {
    width: 40px;
    height: 40px;
    text-align: center;
    font-size: 18px;
}

button {
    padding: 10px 20px;
    font-size: 16px;
    background-color: #28a745;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
}

button:hover {
    background-color: #218838;
}

#solution {
    margin-top: 20px;
    font-size: 18px;
    color: #333;
    display: none;
}