body{font-family:Arial,sans-serif;margin:20px;background:#f5f7fa}h1{color:#2563eb}button{margin-right:10px;margin-bottom:10px;padding:8px 12px;border:none;background:#2563eb;color:#fff;cursor:pointer;border-radius:4px}button:hover{background:#1d4ed8}pre{background:#111827;color:#e5e7eb;padding:10px;border-radius:6px}