Add support for automatic CSS dark mode

[s0ph0s-dog]

This change uses the CSS color-scheme property (widely available as of 2022 according to MDN ¹) to opt FAExport's web interface in to automatic CSS light and dark mode. This change should be invisible to browsers that do not support color-scheme, since it has no other effects, and browsers that do not support the property will continue to display FAExport in light mode, as they always have.

In order to make the navigation links visible in dark mode, I also changed the text color from #000000 to CanvasText, which selects the default text color. This color name has been available since 2015, according to MDN ². If you'd prefer, I can add the CanvasText line after the original #000000 line, so that browsers which do not support the system-color data type will still display the links in black text. (That shouldn't be an issue for dark mode, since a browser that doesn't support system-color will almost certainly not support color-scheme :P)

Motivation: I got flashbanged by FAExport at 2:30 am and realized that I could fix that :3

Footnotes

1. https://developer.mozilla.org/en-US/docs/Web/CSS/color-scheme ↩

2. https://developer.mozilla.org/en-US/docs/Web/CSS/system-color ↩

[Deer-Spangle]

Sorry I haven't gotten to this. Do you have any screenshots, perhaps?

[s0ph0s-dog]

No problem! It's a hobby project, and "add dark mode" is not very important :P

Here's how it looks in Firefox (I have my browser's default font set to Libertinus Serif, which is why the font is different):

And here's how it looks in Safari:

[Deer-Spangle]

Oh yeah, that looks great! Thank you so much! I'll try and get that released and deployed soon. (Having a little bit of an issue setting up a local development environment for this at the moment)

[Deer-Spangle]

I've got that deployed as version 2025.12.1 now, thank you again!