Just took a casual look. This is great!

I was planning on using Semantic UI modules for the interface of advanced search, which requires JavaScript content. We therefore must think about whether or not the search page should be accessible locally (or even offline) which would mean adding an npm dependency.

That should be fine, as long as the new dependencies are managed by Nix.

As for offline, that's not even supported right now (see src-bin/Main.hs which is pulling semantic UI css from CDN, as well as mathjax) - but we probably should (i.e., copy over semantic ui files using Rib.buildStaticFiles) - but that happen in a different PR.

A couple of comments regarding the footer:

• The search icon should be placed before the z-index tree icon (which remains at the end)
• The icons are not aligned with equal gaps (unless editUrl is enabled). See screenshot

Here, the search icon should be at the center, with the z-index icon placed in the far right. If editUrl is enabled, all the four icons should be spaced equidistantly.

Also, search doesn't work in the local version (neuron open). Maybe embedding the JSON in search.html is a solution ...