.container {
max-width: 400px;
margin: 0 auto;
font-family: Arial, sans-serif;
}
label {
display: block;
margin: 10px 0 5px;
}
input, select, button {
width: 100%;
padding: 10px;
margin: 5px 0;
}
.result {
font-weight: bold;
margin-top: 20px;
}