The only thing I could think of was to have some kind of browser extension, that works something like this: 1. Start the extension scan 2. Scan all extern

The only thing I could think of was to have some kind of browser extension, that works something like this: 1. Start the extension scan 2. Scan all external CSS currently in use (page load) 3. Scan all inline CSS currently in use (page load) 4. Monitor (this is the missing piece of the puzzle): Developer uses the app and extension monitors new AJAX or JavaScript added CSS rules 5. Developer clicks a Finish and Report button: a) Warning for inline CSS that could be moved externally b) Warning for external CSS that is never used c) Export (per CSS file, or combined and minified) CSS files, with unused CSS removed.