What is the smallest CSS files that can provide a grid, be responsive and handle cleaner presentation of base HTML elements?
As well as reducing the carbon footprint of pages - tiny CSS libraries improve speed (Amazon apparently found each 100ms delay cost them over a billion - unreferenced claim from here)
By Francisco Presencia - under 10kb, includes js-free CSS transitions for multi-step forms, for instance. Builds on SASS. Includes TABs based on Felipe Fialho's work. https://picnicss.com/
2kb gzipped. Nice and elegant - handles all the basics, with two button defaults (solid and outlined). https://milligram.io
400 lines - covers the basics, built around Raleway so has a minimal clean look. Uses Normalize.css a widely used reset library.
CSS-only no-JS libraries