Iguana is a tiny CSS image-filter library.
You may also be interested in ...
PaperCSS
The less formal CSS framework.
Tailwind Kit
A beautiful and large components kit for TailwindCSS 2.0. tailwind Kit gives you access to over 200 CSS responsive components, based on Tailwind CSS 2.0 and Font Awesome. It's all free and open-source.
Amburgers
Tasty CSS-animated hamburgers by Jonathan Suh