:root{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,sans-serif;color:#111827;background:#f9fafb}body{margin:0}.app{max-width:720px;margin:48px auto;padding:0 20px}h1{font-size:22px;margin:0 0 8px}p.muted{color:#6b7280;font-size:14px;margin:0 0 24px}.card{background:#fff;border:1px solid #e5e7eb;border-radius:10px;padding:24px;margin-bottom:16px}label{display:block;font-size:13px;color:#374151;margin-bottom:6px}input{width:100%;padding:8px 10px;font-size:14px;border:1px solid #d1d5db;border-radius:6px;box-sizing:border-box}.tabs{display:flex;gap:8px;margin:16px 0}.tab{padding:6px 14px;font-size:13px;border:1px solid #d1d5db;background:#fff;border-radius:6px;cursor:pointer}.tab.active{background:#3b82f6;border-color:#3b82f6;color:#fff}button.primary{padding:8px 14px;font-size:14px;background:#3b82f6;color:#fff;border:none;border-radius:6px;cursor:pointer}.result{margin-top:16px;padding:12px;background:#f3f4f6;border-radius:6px;font-family:ui-monospace,SFMono-Regular,monospace;font-size:12px;word-break:break-all;white-space:pre-wrap}.result.error{background:#fef2f2;color:#991b1b}