Hey,
With introduction of TemplateStyles [1], there is no need to put CSS of all templates like Navbox in Common.css [2] anymore, You can simply put them in a page like [3] and inject those into DOM when needed (that makes lots of sense for templates with limited usage because Common.css is loaded on *every* page). So I started a big clean up of the common.css page [4] and now 8 kilobyte is removed from there, with minification and gzip compression that's around one kilobyte less in every request which adds up to around 4 Terabyte of data every month (not to mention CPU usage in our infra to minify and compress the given CSS).
If you see any template misbehaving, let me know. It might be caused by this cleanup.
Best