Learn CSS Programming

Newbie. I've tried other apps and quit on iOS and Android. I've just started this one, but just a cursory look and I'm very impressed. Non-intrusive, no screen hogging, or pop up, ads. Covers both why and how without brainy effort requirement. The content range and structure of the presentation are exceptional. The order the info is given; complete but not wordy; clear, well formatted content, nice font, and clean gui - make it highly readable and efficient; not tediously overwhelming or broken into micro bits requiring lots of page turning - easy to see info and absorb; all lead to a comfy and effective learning experience. Also a valuable future reference tool. Thank you for such a great app and free! I'm trying to learn in order manage (customize and fix) my WordPress websites in the backend, nothing in print or in apps covers that for newbies. I need to learn advanced things but I don't plan to be a programmer - this fills the niche. So, I've download several others in the series that I'm sure will serve me well. I've been searching a very long time, such a relief! Much sincere appreciation.