body {
    font-family: sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    text-align: center;
    background-color: #f0f0f0;
}

.container {
    background-color: white;
    padding: 2em;
    border-radius: 8px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
}

input[type="number"] {
    padding: 0.5em;
    font-size: 1em;
    width: 100px;
    text-align: center;
}

button {
    padding: 0.5em 1em;
    font-size: 1em;
    cursor: pointer;
    border: none;
    background-color: #4CAF50;
    color: white;
    border-radius: 4px;
    margin-top: 1em;
}

#result {
    margin-top: 1em;
    font-size: 1.2em;
    font-weight: bold;
}