body {
    font-family: Arial, sans-serif;
    background-color: #f0f0f0;
    margin: 0;
    padding: 0;
}

.container {
    max-width: 700px;
    margin: 50px auto;
    background: #fff;
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 0 10px rgba(0,0,0,0.1);
}

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

h2 {
    margin-top: 20px;
    color: #444;
}

label {
    display: block;
    margin-top: 10px;
}

input[type="number"] {
    width: 100px;
    padding: 5px;
    margin-top: 5px;
    margin-bottom: 10px;
    border: 1px solid #ccc;
    border-radius: 4px;
}

button {
    margin-top: 20px;
    padding: 10px 20px;
    background-color: #28a745;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 16px;
}

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

#result {
    text-align: center;
    margin-top: 30px;
    color: #007bff;
    font-size: 24px;
}

footer {
    text-align: center;
    padding: 15px;
    background-color: #333;
    color: white;
    margin-top: 30px;
}