An 8086 CPU, chipset, 640 KB RAM, floppy, keyboard and VGA screen in one .css file.
It’s a morbidly obese 300+ MB of spec-compliant CSS, abused beyond recognition; some of the most delightfully painful and wasteful code ever cursed to exist.
It boots Microsoft Windows 1.0 and its namesake MS-DOS, and runs real ’80s software.
Yes, it runs DOOM*
* barely.