Tips in the Greek course render poorly
OS: Ubuntu 18.04.
Browser: Firefox 67, Firefox 68.
See screenshot: https://i.redd.it/7to850lzcx231.png. Notice how the table has taken over the second column.
The situation is much worse in the mobile version of the website (tested with Firefox Focus on Android). There, I cannot see the third column at all.
I have the same in some other courses. Zoom out your browser, it solves the problem.
Try to report a bug.