Light mode now available

Personally I prefer dark mode most of the time, but I can understand the desire for a good light mode theme, such as when in direct sunlight or whatnot. Or just because it’s what you prefer! Who am I to judge?

So this site’s CSS now detects whether you prefer light or dark mode (as determined by your system’s settings, not by reading your mind or anything. Yet) and sets the color scheme accordingly. Hurray!