body {
  font-family: sans-serif;
  padding: 20px;
  max-width: 800px;
  margin: 0 auto;
}

.card {
  border: 1px solid #ccc;
  padding: 12px;
  margin-bottom: 12px;
}

.output-box {
  background: #eee;
  padding: 8px;
  min-height: 40px;
  margin: 8px 0;
}

button {
  cursor: pointer;
  padding: 6px 12px;
}