当我运行'npm start'时，应用程序启动正常，但是'npm run build'在终端中给我以下消息：
> workout_tracker@0.1.0 build /Users/*******/mern-workout/client
> react-scripts build
Creating an optimized production build...
Failed to compile.
./src/Components/UI/Spinner/Spinner.module.css
Module build failed: BrowserslistError: Unknown browser query `dead`
at Array.forEach (<anonymous>)
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! workout_tracker@0.1.0 build: `react-scripts build`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the workout_tracker@0.1.0 build script.
npm ERR! This is probably not a problem with npm. There is likely additional
logging output above.
npm ERR! A …