Sirchuy,
To provide a customer opinion, I want to point out that you do have to poke into various places to implement styling/customizations, which can be frustrating to figure out. Some classes, etc. are not documented and some elements are inconsistently implemented; sometimes you are overriding a CSS class; other times it's an ID, etc. I usually Firefox and a developer addon to figure out which element I need to focus on.
Some customizations I have implemented via portal.css, some via the Language editor, and still others by modifying the .ascx (which I don't like to do since it mostly will get overwritten by a new release).
To be fair to Chris and Engage, it's no worse than most other DNN-based products. I'm looking forward to this being standardized/templated in the future releases.