Use configured background color during initialization

[jpovixwm]

When using the dark theme, this will shorten the user's exposition to the eye-blinding white background during startup.
If custom color overrides were set up using a prior version of TrguiNG, the user will need to re-apply their custom colors, because otherwise the computed property will not be present. I don't think it's worth it to try and handle this edge case, so I left it as is.

[qu1ck]

Move this to loader.css.
Also spinner needs to be a bit brighter in dark theme for contrast.

[jpovixwm]

Also spinner needs to be a bit brighter in dark theme for contrast.

So I'd need to move border-color from loader.css into index.ts and apply a brighter color depending on configured theme? Or is there a trick to keep that in the css file and still have it depend on the chosen theme?

[qu1ck]

move border-color from loader.css into index.ts and apply a brighter color depending on configured theme

Either that or use additional class for dark theme overriding the border-color.

[jpovixwm]

It seems so obvious now 😂
Anyway, let me know if you want me to change the implementation to use that additional class.

[qu1ck]

Current implementation is fine, thanks.
Mantine moved away from emotion-like styling and when TrguiNG updates to mantine v7 styling needs to be reworked all over and this will likely be updated too.