:root {
  font-family: system-ui, sans-serif;
  color: #1a1a1a;
  background: #f6f7fb;
}

body {
  margin: 0;
}

.shell {
  max-width: 720px;
  margin: 2rem auto;
  padding: 0 1rem;
}

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

.error {
  color: #b00020;
}

pre {
  overflow: auto;
}