I’m a long time GitHub user (have been using it actively since 2008). I’ve tried to use Gitlab for my new project and found that not only the PR changes UI is broken on safari, but the bug has been there seemingly unnoticed for 1 week. Just try to go to changes or discussion in a merge request to see that the file name bar CSS is completely off and makes it impossible to review on safari.
@valentin This bug was identified in this issue. It has been fixed and that fix will be live once the changes merged in this merge request are released in a release candidate for GitLab.com.