body {
    font-family: Arial, sans-serif;
}
.container {
    max-width: 600px;
    margin: 50px auto;
    text-align: center;
}
input, button {
    width: 80%;
    padding: 10px;
    margin: 10px 0;
}
button {
    cursor: pointer;
}
.result {
    margin-top: 20px;
    font-weight: bold;
}