body { font-family: system-ui, sans-serif; margin: 0; padding: 16px; line-height: 1.7; color: #1f2937; background: #fff; }
main { max-width: 640px; margin: 0 auto; }
pre { white-space: pre-wrap; word-break: break-all; background: #f3f4f6; padding: 12px; }
button { font: inherit; padding: 8px 16px; }
input { font: inherit; padding: 4px 8px; width: 16em; }