Typically on a deployed site the LESS file is compiled automatically into CSS and less.js is not used at all. This takes place via django-compressor
If you install node js for windows and set up the paths correctly it should work seamlessly as soon as you turn the DEBUG flag off (or you can set to always compress as well, it is a setting for django-compressor).
Alternatively you can manually compile all the less files into css before you even start the server, or alternatively look at the current biostar html source and get the compiled css from there and include that as the css file directly:
While we are at it, let me mention that we are developing a new release of Biostars, beta to be launched fairly soon (one or two weeks) that has a substantially simplified styling and deployment, see this:
and the new branch at: