It was a little challenge for me. I got an example from this question and tried to create my own realization of the idea, but using VanillaJS.
Simple UI framework. RSCSS, REM-based sizes, fluid typography and other nice ideas. This website is powered by it.
Unique avatars for your users. No dependencies, VanillaJS, 1.6KB gzipped.
Dark color scheme for Vim. Mostly blue and green colors.