phoenix.css is the styling used so code generated by the phoenix generators doesn’t look ****. If you don’t intend to use the default UI you can delete the whole file as is. The LV related classes in app.css are indendend to be kept even if you scrap the default UI. They’re meant to be updated, but not removed, given they’re essential for the UX of LV pages. No need to search phoenix.css for essential vs non-essential pieces of css.
I can see a case being made that the alert classes should be part of phoenix.css, but tbh I also just delete them once I don’t use them anymore, just like phoenix.css.
