Check out example codes for "hwo to reload css in flask". It will help you in understanding the concepts better.
Code Example 1
if facing no changes quickly then do this content point..... Is it possible that your CSS is being cached by your browser? – ... yes , if i manually reload the server the output is being changed ! – ... Try Hard Refresh - Ctrl + F5 or hold Ctrl and click on the Refresh button on your web browser. –
Learn ReactJs, React Native from akashmittal.com