what is dual mode for in addition to dark/light modes

[copdips]

What's happening?

Hello,

In the dark/light mode switch, it has a third choice like:

After searching in the issues, it seems that this is called dual mode.

Anyone could give a brief description, what is it for?
Because it seems that it has the same effet when I choose dark mode or dual mode.

Reproducer

switch between dark mode and dual mode

Expectation

1. more explanations in the doc
2. options to disable the dual mode, sometimes, dark/light is enough.

Code of Conduct

• I agree to follow the Code of Conduct.

[pradyunsg]

https://pradyunsg.me/furo/customisation/colors/#how-light-and-dark-mode-work

It respects the dark/light mode as requested by the user’s browser.

[pradyunsg]

https://developer.mozilla.org/en-US/docs/Web/CSS/@media/prefers-color-scheme

[copdips]

@pradyunsg
ah okey, it means auto mode based on user preference, thanks a lot for your apply