The order in which we're loading CSS and Javascript is causing some rather unsightly reflows on more complicated pages (e.g. diff pages, recent changes, page editing). Even though the CSS and Javascript is being delivered to the browser faster using Resource Loader, this delivery speed benefit is more than offset by the performance penalties of the reflows.

From Roan: "This is because we're loading the styles for these after the page load, even though the elements are present in the page itself. Obviously this is bad: loading styles after page load is only acceptable for things that get inserted by JS (which happens after the styles are loaded). Flashes of unstyled content should not happen."

This is a work item to find and fix areas where we're loading CSS dynamically where we don't need to, and switch to static loading in those cases

Version: 1.16.x
Severity: major