Don't store dark/light toggle if it matches the OS setting

[odrotbohm]

It would be nice if the CSS could automatically detect whether to use dark or light mode based on the user theme (via media queries).

[philwebb]

We should already do this. See

spring-asciidoctor-backends/src/main/js/setup/switchtheme.js

Line 25 in 6ce6390

"(prefers-color-scheme: dark)"

and

spring-asciidoctor-backends/src/main/js/setup/switchtheme.js

Line 50 in 6ce6390

return theme ? theme === "dark" : prefersDarkColorScheme.matches;

.

The problem might be that the theme has been toggled in the past and saved to local storage.

@odrotbohm What does an incognito window do?

[odrotbohm]

You're right. An incognito window brings up the dark theme on a dark OS. I guess I've clicked on the button just to test the switch at some point. A localStorage.removeItem("theme") did the trick. Wonder if that could be made a bit more convient to reset? Additional icon next to the switch in case a value is set and a click on it removing the value?

[philwebb]

Perhaps we just shouldn't save a local value if it matches the detected one.