Upgraded the Jekyll part of the site from version 3 to 4. This involved adding a proper Gemfile with version pinning, refactoring the SCSS structure to extract variables into a dedicated partial, and updating some template syntax. The build script and Docker setup needed adjustments to work with the new version.

While working on a post I added a new info callout component for highlighted asides. Also set up redirects for the old asteroid-logistics game URLs and improved the CI workflow by caching Ruby gems.