Part of #1332 (end perhaps #151)...
Now with Views in core, we should explore the idea of taking advantage of it and convert the search to a view with exposed filters.
This would allow people to either directly edit the default Search view in order to tweak it to their liking or clone it and create other search views.
It would also expand the ways of extending it with contrib modules that improve the backend (search API) as well as modules that improve the UI (Views).
Recent comments
A simple way — use Field Group to create a container for fields https://backdropcms.org/project/field_group and CSS Flex оr Grid to alignment.
Layout also for /node/add/ forms?
Yes. The are several ways to do this: Install Mail System and select "Testing" for delivery in admin/config/system/mailsystem Install Maillog / Mail developer...
Prevent Backdrop from sending emails
The short answer is no, you can't theme forms or change their layouts through the UI. There is a ported version of Display Suite, which has a submodule called Display Suite Forms that allows you...
Layout also for /node/add/ forms?