When I view the generated index.html file, it does not find the ceur-ws css file since the reference is relative. I do not think it would hurt to make the reference absolute in which case the file would automatically look ok with the right style.
Two possible solutions to make the relative link work:
maintain a physical copy (or even the actual master version?) of ceur-ws.css in the ceur-make repository
Jyrki Nummenmaa:
Two possible solutions to make the relative link work: