Use custom CSS in a selected SharePoint list

Current process:


I have a CSS and JS file in Site Assets that I can render to a list / library using the Content Editor (which references CSS / JS).

Requirement


What I need is that end users can not access these files or can not see the codes in my CSS & JS. So there is a possibility that I can paste the CSS into a master page or somewhere and apply that CSS only to a particular list / library, eg. For example, if we can refer this list / library to a custom list. Only for these lists does my CSS work!