What is CSS pixel art?
CSS Pixel art is the art of using pixels to draw something with CSS.
In a nutshell, you define a unit, for example, 10px, and you fill each pixel with a color.
You can read the great post by Geoff Graham to get more details.
Doing CSS pixel art can have consequences, such as fun and joy.
But don't scale your pixels like me here with the cat. The effect works great at 1:1 scale.