Will all CSS variables be defined in SSR?

[AkiraVoid]

My site has many predefined CSS styles in document head while in SSR, but all variables are undefined.

[ling1726]

Hi, have you followed our SSR documentation?

https://react.fluentui.dev/?path=/docs/concepts-developer-server-side-rendering-basic-setup--page
https://react.fluentui.dev/?path=/docs/concepts-developer-server-side-rendering-nextjs-setup--page

[AkiraVoid]

@ling1726 https://github.com/AkiraVoid/fui-discussion-25714 After you start the server, you will see at first frame all styles are not applied, and then it get normal, and if you put the generated code in SSR into a normal html file, you will see all styles are inserted to document correctly but CSS variables are not loaded.

[AkiraVoid]

Sir, is it possible to reproduce this with my repo?

[ling1726]

Sorry for the wait, I just ran your repo and I see that the CSS variables are defined... maybe I've understood your original question incorrectly, could you please clarify?

[AkiraVoid]

Yes， I mean it seems like it will only load those variables on client because if I use the code generated by the server directly there are no variables are defined, which causes the first few frames of my app are not styled.

[layershifter]

@AkiraVoid There is a feature request to support it, #25425.