function CrowdPanel({config,onChange,time,playing,onPlay,onStep,onReset,running,ready,report,placement,onAddZone,onZoneChange,onRemoveZone}) {
  const number=(label,key,min,max,step='any')=><NumberField label={label} value={config[key]} min={min} max={max} step={step} onChange={v=>onChange(key,Number(v))}/>;
  return <section className="stress-panel">
    <div className="stress-heading"><div><span className="eyebrow">EVENT PLANNING</span><h2>Crowd stress test</h2><p>Model occupancy, body shadowing and sector demand at the selected floor.</p></div><label className="stress-toggle"><input type="checkbox" checked={config.enabled} onChange={e=>onChange('enabled',e.target.checked)}/> Enable crowd</label></div>
    {config.enabled&&<>
      <div className="stress-fields">
        {number('People (used without zones)','count',0,5000,1)}
        <SelectField label="Placement / movement" value={config.layout} onChange={v=>onChange('layout',v)}><option value="grid">Stationary square grid</option><option value="walking">Walking crowd</option></SelectField>
        {number('Active phones %','activePercent',0,100,1)}{number('Demand per active user Mbps','demandMbps',.01,1000,.1)}
        {number('Walking speed m/s','speed',0,3,.1)}{number('Random seed','seed',0,4294967295,1)}
      </div>
      <div className="stress-actions"><button className="primary-action" onClick={onReset} disabled={running||!ready}>Generate / reset crowd</button><button onClick={onStep} disabled={running||playing||!ready}>Advance 1 s & calculate</button><button onClick={onPlay} disabled={!ready||config.layout!=='walking'}>{playing?'Pause playback':'Play crowd & coverage'}</button><span>Simulation time <strong>{time.toFixed(0)} s</strong></span></div>
      <HelpNote>Up to 5,000 explicit people per scenario. Playback advances one simulated second after each completed coverage calculation. Its speed depends on scene size; people and heatmaps represent the same snapshot. Changing crowd settings resets placement and time.</HelpNote>
      {placement&&<p role="status" className="stress-placement">{placement.people.length.toLocaleString()} placed / {placement.requested.toLocaleString()} requested{placement.unplaced?` · ${placement.unplaced} could not be placed on walkable floor`:''}. Orange: active phone. Teal: inactive.</p>}
      <details><summary>Population zones</summary><HelpNote>Zone counts replace the global population. Each rectangle holds its own crowd; walking stays inside that zone. Overlapping zones add their populations. XY coordinates are in model metres.</HelpNote>
        {config.zones.map((zone,i)=><div className="stress-zone" key={zone.id}><strong>Zone {i+1}</strong>{[['Min X','minX'],['Max X','maxX'],['Min Y','minY'],['Max Y','maxY'],['People','count']].map(([label,key])=><NumberField key={key} label={label} value={zone[key]} step={key==='count'?1:.1} onChange={v=>onZoneChange(zone.id,key,v)}/>)}<button onClick={()=>onRemoveZone(zone.id)}>Remove</button></div>)}<button onClick={onAddZone} disabled={!ready||config.zones.length>=12}>+ Add zone from coverage bounds</button></details>
      <details><summary>Body attenuation and phone interference</summary><div className="stress-fields">
        {number('Body attenuation dB per crossing','bodyLossDb',0,30,.5)}{number('Body radius m','bodyRadius',.05,.5,.01)}{number('Body height m','bodyHeight',.5,2.5,.05)}{number('Maximum cumulative body loss dB','bodyLossCapDb',0,60,1)}
        {number('Phone total EIRP dBm','phonePowerDbm',-40,30,1)}{number('Phone occupied bandwidth MHz','phoneBandwidthMHz',.1,400,1)}{number('Phone duty cycle %','phoneDutyPercent',0,100,1)}{number('Phone / receiver band overlap %','phoneOverlapPercent',0,100,1)}
      </div><HelpNote>Phone overlap defaults to 0% for isolated cellular uplink/downlink. Set overlap only for a cochannel or cross-link stress scenario. Active phones are aggregated into source tiles using free-space propagation; this is a conservative interference approximation. Body loss is an adjustable empirical assumption, not a universal human attenuation value.</HelpNote></details>
    </>}
    <details><summary>SNR / SINR settings</summary><div className="stress-fields">{number('Receiver noise figure dB','noiseFigureDb',0,30,.5)}{number('NR subcarrier spacing kHz','subcarrierKhz',15,240,15)}{number('Wi-Fi channel bandwidth MHz','wifiBandwidthMHz',1,320,1)}{number('SNR / SINR pass threshold dB','qualityThresholdDb',-30,50,1)}{number('Minimum admission SINR dB','minSinrDb',-30,50,1)}</div><HelpNote>SNR uses thermal noise at 290 K. SINR also sums other sectors in the same cochannel group and the configured phone interference. Cellular noise is evaluated over one reference subcarrier (LTE 15 kHz); Wi-Fi uses its channel bandwidth.</HelpNote></details>
    {config.enabled&&report&&<div className="capacity-report"><h3>Sector / nodeB capacity at {time.toFixed(0)} s</h3><p>{report.population} people · {report.active} active · {report.blocked} blocked by user limits · {report.poorSignal} below admission SINR · {report.uncovered} without a serving cell</p><div className="capacity-scroll"><table><thead><tr><th>Sector / nodeB</th><th>Attached</th><th>Active / limit</th><th>Demand / budget</th><th>Admitted</th><th>Blocked</th><th>Served</th><th>Per admitted user</th></tr></thead><tbody>{report.rows.map(r=><tr key={r.id} className={r.blocked||r.demandMbps>r.capacityMbps?'overloaded':''}><th>{r.label}</th><td>{r.attached}</td><td>{r.active} / {r.maxUsers}</td><td>{r.demandMbps.toFixed(1)} / {r.capacityMbps} Mbps</td><td>{r.admitted}</td><td>{r.blocked}</td><td>{r.servedMbps.toFixed(1)} Mbps</td><td>{r.perUserMbps.toFixed(2)} Mbps</td></tr>)}</tbody></table></div><HelpNote>Each transmitter is one independent sector/nodeB budget. Association uses strongest received power; no load-balancing handover or scheduler emulation. Throughput is a demand/budget allocation, not a PHY throughput prediction.</HelpNote></div>}
  </section>;
}