Why does adding custom css break the navbar?

[Sadie Stokes]

Hello,

I am trying to use custom css on my confluence space and when adding anything or even adding a stylesheet link to a blank css doc the navbar completely messes up. This only happens on one of my spaces but not sure what the issue is.

[Barbara Szczesniak]

@Sadie Stokes Welcome to the Atlassian Community!

Your question is tagged with Confluence Cloud, but, since you cannot use custom CSS with Cloud, are you actually using Data Center (as indicated by the page that @John D Patton linked to)?

[John D Patton]

Here is the official Atlassian Doc
https://confluence.atlassian.com/doc/styling-confluence-with-css-166528400.html

I would suggest to take a look at the syntax of your css using a validator - usually it is something like an open tag

https://codebeautify.org/cssvalidate

https://jigsaw.w3.org/css-validator/