I'm guessing you need to upgrade your qa-styles.css file for the latest version of Q2A. Take a look at the .qa-nav-cat-XXX lines in the qa-styles.css file for the default theme and copy those to your own file.
Welcome to the Q&A site for Question2Answer.
If you have a question about Q2A, please ask here, in English.
To report a bug, please create a new issue on Github or ask a question here with the bug tag.
If you just want to try Q2A, please use the demo site.