Add a style inversion script and bundle css in single file on build

[EresDev]

reference: #277 (comment)

We want to write css that is used for the dark theme by default. And the styling for the light theme should be generated automatically by a script on build. There is a script that does similar work in work.ubq.fi repository. Don't hesitate to use it if it is helpful.

With this script, you will also have to refactor the existing CSS.

Currently, multiple CSS files exist for different purposes, e.g., light mode, gift card, rewards. It will be a good idea to bundle the CSS in a single CSS file on build so that the web page loads only one CSS file.

[Keyrxng]

I'm wondering how essential this actually is if we are moving to a framework soon, where this is easily handled with simple plugins, packages or theme providers?

[0x4007]

Should be a brand new repo. Keep this one no framework.

[EresDev]

I'm wondering how essential this actually is if we are moving to a framework soon.

I think even if we move to a new framework or not, the new script we are planning to introduce here, may end up adding more issues than it solves. But that could be my lack of experience with such CSS automation. I would like to keep the CSS the way it is. It is not too complex to automate.

Should be a brand new repo. Keep this one no framework.

I believe you are referring to above comment by Keyrxng. It is not a part of change in the specification of this issue?