body {
  font-family: sans-serif;
  margin: 20px;
  max-width: 600px;
}

label {
  display: inline-block;
  width: 180px;
  font-weight: bold;
}

form > div {
  margin-bottom: 10px;
}

button {
  padding: 5px 10px;
  cursor: pointer;
}

.result {
  margin-top: 20px;
  font-weight: bold;
  font-size: 1.1em;
  color: #333;
}