* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
  background: #f4f5f7;
  color: #1f2937;
}
main { max-width: 720px; margin: 0 auto; padding: 32px 16px 48px; }
h1 { margin-bottom: 4px; }
.subtitle { color: #6b7280; margin-top: 0; }
.card {
  background: #fff;
  border: 1px solid #e5e7eb;
  border-radius: 12px;
  padding: 20px;
  margin-top: 16px;
}
.card h2 { margin-top: 0; font-size: 18px; }
input {
  padding: 10px 12px;
  border: 1px solid #d1d5db;
  border-radius: 8px;
  min-width: 240px;
}
button {
  padding: 10px 16px;
  border: 0;
  border-radius: 8px;
  background: #111827;
  color: #fff;
  cursor: pointer;
}
button:hover { background: #374151; }
form { display: flex; gap: 8px; flex-wrap: wrap; }
pre {
  background: #f9fafb;
  border: 1px solid #e5e7eb;
  border-radius: 8px;
  padding: 12px;
  white-space: pre-wrap;
  word-break: break-word;
  margin-bottom: 0;
}
.note { background: #fffbeb; border-color: #fde68a; }
code { background: #f3f4f6; padding: 1px 5px; border-radius: 4px; }