Hello, @Bas Kling,
Your issue has been solved please check back to your site now after removing the browser cache. One of your Custom CSS was generating this issue, I commented it out and the issue resolved, here are the screenshots:
https://postimg.cc/LnCkn3rj
https://postimg.cc/TK5bhMjX
https://postimg.cc/bdrjFyJw
Regards 8Themes Team.