CSS is a styling language used for web development, allowing designers to control layout, colors, fonts, and overall visual appearance of websites. Client-side modifications refer to changes made to CSS on the client's (user's) browser, as opposed to server-side changes, which occur on the web server.
Are you a developer working on a game? Audit your WebView. Are you a player? Don't inject strangers' CSS files into your premium Steam account. It ends badly. css client mod cheat
The moment you use a client-side rendering trick to gain an advantage another human does not have, you have crossed the line. It doesn't matter if the code is "just CSS" or "just JavaScript." It is an exploit. CSS is a styling language used for web