A new user to Backdrop asked the following question in Gitter today, it seems like a question that other might have, so I'm posting it here in the forum. 

"Using the Backdrop default theme and need to make CSS changes. (Menus are HUGE, hero block has more padding than the presidential bank account.) Spelunking through inspector properties and CSS files, it appears some are programmatically generated, and I have no idea where to make edits. Help?"


Replies in Gitter (and links to various resources below)

"...I think that your best option is a combination of a) creating a subtheme of Basis and the overriding the CSS there (please let us know if you need more help with subtheming - but in general it works the same way as in D7), and b) tweaking your layouts." (Gregory Nestas)

"as you are inspecting CSS, be sure to disable the CSS aggregation setting (at /admin/config/development/performance) so you can see exactly where the CSS code is coming from. Some comes from the Basis theme, and some comes form deep within core. Neither should be changed directly, but all can be overridden! Let us know if you need help with anything specific :)" (Jen Lampton)

User guide section about themes: https://backdropcms.org/user-guide/themes

Here is an article from BackdropCMS.org on porting themes: https://api.backdropcms.org/converting-themes

You can post a port request for a theme or a module here: https://github.com/backdrop-ops/contrib/issues

Here are some links to previous forum topics that might help you get started:

A spreadsheet to help compare contrib themes (info is dated).


If you just want to make some minor changes to the CSS through the user interface, you might be interested in the CSS Injector module.

Please, post any follow up questions here and we'll try to help out.

Also - I'm working on a new contrib theme call Tatsu for Backdrop that fixes a lot of the small problems/frustrations I have with Basis. It's still not finished, but I'd love for folks to try it out and let me know what else it needs. 

Theme: https://backdropcms.org/project/tatsu Dev version is better: https://github.com/backdrop-contrib/tatsu

Blog post: https://www.triplo.co/blog/new-contrib-theme-backdrop-cms-tatsu

Feedback: https://github.com/backdrop-contrib/tatsu/issues/47

I'm the new user in question and just came by to post the same thing—thanks for beating me to it!