:root { color-scheme: light; }
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: Inter, system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  background: #f5f7fb;
  color: #0f172a;
}
.wrap { max-width: 860px; margin: 40px auto; padding: 0 16px; }
h1 { margin: 0 0 8px; }
.muted { color: #64748b; margin-bottom: 18px; }
.card {
  background: #fff;
  border: 1px solid #e2e8f0;
  border-radius: 12px;
  padding: 16px;
  margin-bottom: 12px;
}
button {
  border: 0;
  background: #2563eb;
  color: #fff;
  padding: 10px 14px;
  border-radius: 10px;
  cursor: pointer;
}
pre {
  margin-top: 12px;
  background: #0b1020;
  color: #d1e7ff;
  padding: 12px;
  border-radius: 8px;
  overflow: auto;
}