:( It seems like the CSS failed to load. Please try clearing your cache to redownload the styles:
Ctrl / Cmd + Shift + R
You could also try to reinstall the service worker:
Reinstall
Various dark mode extensions are also known to cause this issue. If that doesn't help contact support (support@crococalc.com) If the website works for a bit but then this screen comes back, clear your cache again and then on croco calc open the command line (esc) and search for "Clear SW cache".