* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    text-align: center;
    font-family: Arial, sans-serif;
    background-color: #f0f0f0;
    padding: 20px;
}

div {
    background-color: white;
    padding: 30px;
    border-radius: 10px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
    max-width: 400px;
    margin: 50px auto;
}

h2 {
    color: #333;
    margin-bottom: 20px;
    font-size: 24px;
}

label {
    display: block;
    margin-bottom: 8px;
    color: #555;
    font-weight: bold;
}

input[type="number"] {
    width: 100%;
    padding: 10px;
    margin-bottom: 20px;
    border: 2px solid #ddd;
    border-radius: 5px;
    font-size: 16px;
    transition: border-color 0.3s ease;
}

input[type="number"]:focus {
    outline: none;
    border-color: #007bff;
}

#b1 {
    background-color: blue;
    color: white;
    padding: 12px 25px;
    margin-right: 15px;
    border: none;
    border-radius: 5px;
    font-size: 16px;
    font-weight: bold;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

#b1:hover {
    background-color: darkblue;
}

#b1:active {
    transform: scale(0.98);
}

#b2 {
    background-color: red;
    color: white;
    padding: 12px 25px;
    border: none;
    border-radius: 5px;
    font-size: 16px;
    font-weight: bold;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

#b2:hover {
    background-color: darkred;
}

#b2:active {
    transform: scale(0.98);
}

#message {
    margin-top: 20px;
    font-size: 16px;
    font-weight: bold;
    color: green;
    min-height: 20px;
}

#message:empty {
    display: none;
}