body {
  font-family: sans-serif;
  margin: 2rem;
  max-width: 600px;
}

header {
  margin-bottom: 1.5rem;
}

.card {
  border: 1px solid #ddd;
  padding: 1rem 1.5rem;
  border-radius: 8px;
  background: #fafafa;
}

label {
  display: block;
  margin-top: 1rem;
}

input {
  width: 100%;
  padding: 0.4rem;
  margin-top: 0.25rem;
}

button {
  margin-top: 1rem;
  padding: 0.5rem 1rem;
  cursor: pointer;
}

#result {
  margin-top: 1rem;
  padding: 0.75rem 1rem;
  background: #e8f5e9;
  border: 1px solid #c8e6c9;
  border-radius: 6px;
  display: none;
}

#result.is-visible {
  display: block;
}