Switch between a normal "light" color scheme and dark night mode theme in Wordpress?


Staff member
I've been asked to implement a Day/Night mode in the page I'm maintaining.
The idea is that the default theme is a light coloured theme with light background and darker fonts and pressing a button swithing to night mode and back.

In a hand made site this looks easier by only switching between 2 .css files or overwritting colours with another one when required, at least that's how I think I would do it.

But in wordpress I don't know what would be the best way to achieve this.
I looked for a plugin that does this and inverts my styles colours in some way to create a dark mode but could not find anything like this.
As I see I will have to do it myself manually, what would be the better logical way of achieving this?

Just asking about the procedure and what files should I modify or touch.
Should I create another style.css and change it? Would it affect only the user that is performing the change on his/her browser and not globally?