starlight

Description Closes #3721 This PR updates our default font stack in an attempt to handle the cases described in the linked issue It kind of does the opposite of #3549, bringing back and fonts and removing the newer and families. Todo We should try to test on a broad range of browsers and devices: macOS [x] macOS — English (@HiDeoo & @delucis) [x] Chrome (v145): Tested pages in various languages on an English-language macOS (15.7.3 and 26.3) install, no visual change after this PR [x] Firefox (v148): Same as above [x] Edge (v145): Same as above [x] Safari (v26.2): Same as above Windows [x] Windows 10 Pro — English (@HiDeoo) [x] Chrome (v145): Tested pages in various languages, no visual change after this PR [x] Firefox (v147): Same as above [x] Edge (v145): Same as above [x] Windows — Japanese (@mehm8128 and @tats-u) [x] 🚨✅ Japanese characters are now displayed with Segoe UI instead of system-ui (see comment) [x] 🚨✅ Firefox: Simplified Chinese characters are now displayed correctly on a Japanese machine (see comment) [x] Windows 11 — Simplified Chinese (@tsavpyn) [x] 🚨✅ Firefox (v147): Latin fontface has changed, Simplified Chinese is unchanged, Japanese characters are now displayed correctly, e.g. instead of (see comment) iOS [x] iOS 26.3 — English (@HiDeoo) [x] Safari (v26.3): Tested pages in various languages, no visual change after this PR [x] ipadOS 26.3 — English (@HiDeoo) [x] Safari (v26.3): Tested pages in various languages, no visual change after this PR Linux [x] Endeavour OS virtual machine hosted on Windows — English (English host) (@HiDeoo) [x] Firefox (v146): Tested pages in various languages, no visual change after this PR [x] Chrome (v145): Same as above [x] Fedora 43 virtual machine hosted on Windows - English (English host) (@HiDeoo) [x] Firefox (v147): Tested pages in various languages, no visual change after this PR [x] Chrome (v145): Same as above [x] Ubuntu 24.04.4 virtual machine hosted on Windows - English (English host) (@HiDeoo) [x] 🚨❓ Firefox (v147): Tested pages in various languages, some visual change after this PR (see comment) [x] 🚨❓ Chrome (v145): Same as above Android [x] Android 11 (old!) — English (@delucis) [x] Chrome: Tested pages in various languages, no visual change after this PR [x] Firefox: Same as above I would love help testing this! I don’t have Windows/Linux boxes to test on personally. And testing on machines in CJK locales would be particularly useful. To test, you can compare the deploy preview for this PR with the live Starlight docs. Check if appearance of fonts change in multiple languages and note any differences if there are any.

Description This draft PR is a very early version of a rewrite of the Pagefind UI that is used in Starlight. This is a work in progress and is not ready for production or even for a full review yet. A lot of work is still needed to get it to a point where it can be used in Starlight. Most of the work has only been done in 1 browser and parts of the UI have been tested in isolation against only 1 screen reader so far so it'll require a lot of testing and improvements before it can be considered ready in its entirety. The main goal of having more control over the search UI and improving the accessibility of the search experience in Starlight. A few important points to note: ~~Filters are always visible as some have been configured in the content which is not the case in the live version of the documentation.~~ Translations are now part of Starlight although I did not port the existing ones from the original Pagefind UI. That was my original idea although after checking the French one, I was not pleased with some of the translations. We can think about it later. Most of the UI mimics the original Pagefind UI as closely as possible to iterate faster on a working veersion. Only a few parts may have changed, e.g. always-visible query input or filters disclosure icon now matching the one used in the Starlight Markdown UI, etc. The current UI used in the live version of the documentation was potentially limited due to the lack of control when using the original Pagefind UI. Something to potentially consider later is if there are any changes to the original UI that we would like to see in this version. ~~Something coming to mind could be an always-visible query input but that's a decision that should be made later. This PR implements an always-visible query input but it's not looking great and was mostly done to make testing easier (in a dedicated commit so it can be easily reverted later if needed).~~ ~~An interesting search is :~~ ~~It displays some metadata.~~ ~~With this branch not being updated with #3276, the banner content of the homepage is still indexed and this search will display it as a single root result with an excerpt and no sub-results (which is not broken like in #3267).~~ Development notes: This PR adds the command to the directory which should be used when iterating on this PR: It simultaneously runs a dev version of the docs running on the port and a prod version on the port. When developing, visiting will use the search indexes from the prod version which allows for using/testing/iterating on the search UI (note that changes that would result in a change to the search indexes will require running the command again). Remaining todos [ ] Look for any remaining comments and address them. [ ] Add changeset(s)