:root{color-scheme:light dark;font-family:system-ui,-apple-system,Segoe UI,sans-serif}body{margin:0;display:grid;place-items:center;min-height:100vh;background:#0f172a}.card{width:360px;padding:28px;border-radius:14px;background:#fff;color:#0f172a;box-shadow:0 10px 40px #00000059}h1{margin:0 0 16px;font-size:22px}.tabs{display:flex;gap:8px;margin-bottom:16px}.tabs button{flex:1;padding:8px;border:1px solid #cbd5e1;background:#f8fafc;border-radius:8px;cursor:pointer}.tabs button.on{background:#2563eb;color:#fff;border-color:#2563eb}form{display:flex;flex-direction:column;gap:10px}input{padding:10px;border:1px solid #cbd5e1;border-radius:8px;font-size:14px}form button{padding:10px;border:0;border-radius:8px;background:#2563eb;color:#fff;font-weight:600;cursor:pointer}form button:disabled{opacity:.6}.err{color:#dc2626;font-size:13px;white-space:pre-wrap}.ok{color:#16a34a;font-size:14px}pre{background:#f1f5f9;padding:12px;border-radius:8px;font-size:12px;overflow:auto}