The goal of this CSS (Not XSS, but Cascading Style Sheet) Cheat Sheet is to inform Programmers, Testers, Security Analysts, Front-End Developers and anyone who is interested in Web Application Security to use these recommendations or requirements in order to achieve better security when authoring CSS. The risk is that attackers could map these selectors to actual features of a web application that might be specific to an individual or group of roles. As a CSS Coder / Programmer, always keep the CSS isolated by access control level.”]
Source: https://cheatsheetseries.owasp.org/cheatsheets/Securing_Cascading_Style_Sheets_Cheat_Sheet.html