arda well there are two things:
- A Less file requires compilation into CSS
- Flarum variables are only available if the file is parsed by Flarum Less parser
Based on that, your current, <link>-based install solution does not satisfy either of those. The file will be read as simple CSS and the browser will encounter syntax errors.
Also you could pre-compile your Less files and store the resulting CSS into the GitHub repo (or use GitHub pages to let GitHub compile it on the fly), but you wouldn't be able to use Flarum variables because those are only available inside Flarum.
The only (clean) solution here is to load the Less file either via the Custom Less setting or via a Flarum extension that serves as a theme.
Then of course there would be solutions involving scripts added to the custom header but that would quickly get very messy. Flarum is easily extensible so an extension-based solution would be preferable ?
