Okay, well the reason you need to use the “.psc-” prefix is to avoid potential collision between Perspective Style Class names and classes that we supply by default.
For example:
I’m using a Button component and I want to create a Style that I think describes how this primary Button should look. I name this Style “ia_button–primary”.
In this case, if we hadn’t attached the “psc-” prefix to the style class, all primary Buttons would use your Style - instead of only the ones you apply that Style Class to, because the theme-specified “ia_button–primary” class would have its values overridden by your Style Class of the same name.