The thing is, that sometimes javascript is a lot easier that 40 lines of css.
The point is that a person reading system logic shouldn't need to be distracted by layout, and a person worried about styling shouldn't need to think about code.
Whether that matters depends on the specific system and the types of abstractions used, but it can be very important to making code maintainable, and in some cases, org structures practical (where the team maintaining the CSS might not be the same as the team maintaining the system logic).
Is it possible to use one for the other? Of course.
There’s no “right place”.
It’s a web browser. You program it in whatever way you like that you enjoy that makes sense to you.
Use whatever approach you need to get the job done. Mix and match. Come up with new ways. Do it simple. Do it sophisticated. Combine JS and CSS. It’s all valid.
Don’t listen to people who try to tell you how to program.
This worked for me:
* DO listen to people who tell you how to program
* Listen to many types of them (Microsoft programmers, functional programmers, Unix systems wizards, digital logic designers, UX designers, etc.)
* Do what they tell you for at least long enough to understand why they're telling you what they're telling you to do. This requires a very open mind. A Unix programmer stepping into a Microsoft shop or vice-versa will find many things which go against their most core values.
* Understand the underlying, fundamental, first principles their best practices derive from (keeping in mind some of those first principles are incorrect -- especially within the Microsoft community), and different ways people have figured out how to structure code, the upsides and downsides of each, and how they mix-and-match.
* From then on, program from first principles when you have time, from best practices when you don't, and quick-and-dirty hacks when you really don't, or are just having fun.
Yeah that’s showing an incomplete understanding of web application development.
I never really got my head around the correct way to think in CSS.
I am at the "I can see numerous ways of doing this" but I never really know the standard or best way to do it. It was the same when I started doing web dev / Django stuff, whereas now, with years of experience, I do know the best way to approach a problem, to keep code minimal and clean and readable.
(If anyone can suggest some tutorials that get me past that stag with CSS I would grateful).