How to Force Reload any Cached CSS File (Local, Remote, or on a CDN)

There’s nothing more frustrating than a machine that refuses to do what you tell it. “Reload the page” – a simple action, that causes so much frustration for developers because it sometimes just doesn’t work. CSS files often don’t get reloaded. Yes, we all know cache is to blame but how to get around it without drastic measures? Years of frustration have led me to this simple one-click solution that works on any page and with any cache type. What causes the problem?
Cache is a wonderful thing. It lowers resource usage on all levels and enables us to surf faster. Problems occur when we want to get around the cache and grab a fresh copy of the file. There are an unlimited number of reasons why cache won’t purge, but they all fall into two categories;
1. The browser doesn’t want to request the new file
Anything browser related is a local problem. The browser has a copy of the file in its cache and continuously serves it to you. It doesn’t want to request a new file from the server. Problematic files are usually CSS, JS, and images, but it’s not limited to any specific file-type as everything depends on the headers which control
Source: https://managewp.org/articles/17956/how-to-force-reload-any-cached-css-file-local-remote-or-on-a-cdn

source https://williechiu40.wordpress.com/2018/10/09/how-to-force-reload-any-cached-css-file-local-remote-or-on-a-cdn/