force update CSS on all clients
This is a nice hack I like to use when I'm working on updating / reworking a website design is to append a [query string](https://en.wikipedia.org/wiki/Query_string) to my CSS file
`https://.../style.css` becomes `https://.../style.css?v=1`
the 'v' is for version but could be anything really.
by changing the number after '=' you can really easily force clients to update the CSS file they're using and force the new version to be downloaded and used instead
otherwise the browser will cache the file
and all browsers have their own behavior when it comes to caching