And don't forget lite mode: https://duckduckgo.com/lite

just waiting for DDG lite 'n dark

I can't tell if this is sarcasm or you're actually giving too much weight to 3 lines of css.

And you way under estimate how much work it takes to make and maintain a proper dark mode across a site. If it was truly 3 lines of CSS, every single website out there would have native dark mode.