function main() {
  const r=$data.current;
  const previous=$sessionStorage.get('peakSpeedMPS');
  const peak=r.speedMPS===null?previous:Math.max(previous??0,r.speedMPS);
  if(peak!==null) $sessionStorage.set('peakSpeedMPS',peak);
  const shown=peak===null?null:peak*(r.speedUnit==='mph'?2.2369362921:3.6);
  return <CardContent title="本次峰值" trailing={r.speedUnit}>
    <VStack spacing={8}>
      <Text fontSize={58} color={$env.foreground} contentAnimation={{type:'numericText'}}>
        {shown===null?'—':Math.round(shown)}
      </Text>
      <Text fontSize={11} color={$env.accent}>随本次记录结束清空</Text>
    </VStack>
  </CardContent>;
}