What is UI CSS?

It's a set of UI components written entirely in CSS (Sass) and HTML (Jade).

Can I use it on my projects?

Yes, you can. But I do not recommend, as it's meant only for study purpose and it can have browser support issues.

Demo

UI CSS Tooltip

http://codepen.io/AndersonMamede/pen/wKJZzX

UI CSS Checkbox

http://codepen.io/AndersonMamede/pen/EVWJwP

UI CSS Radio

http://codepen.io/AndersonMamede/pen/YyZMrx

UI CSS Treeview

http://codepen.io/AndersonMamede/pen/ojWPmW

UI CSS Floating Label

http://codepen.io/AndersonMamede/pen/GpEEpb