easyadmin 3 demo css is using the variables from app.css but not from variables.scss/variables.css Why?

So I am very new to easyadmin 3 and symfony 5^ and I am just trying to change simple CSS style (Color etc.). I've found the Variables.scss/Variables.css files which contain a lot of variables that would be perfect to use, but somehow nothing reads from these files. I could delete both of the css/scss files and I will get no error, therefore I think no file is trying to access all those variables. Instead, I have alot of variables very hard to read in app.css and it's definitly using these variables.

How do I use the Variable.css/scss variables? Thanks