Semantic is a UI component framework based around useful principles from natural language
Key Features
50+ UI elements
3000 + CSS variables
3 Levels of variable inheritance (similar to SublimeText)
Built with EM values for responsive design
Flexbox friendly
Semantic allows developers to build beautiful websites fast, with concise HTML, intuitive javascript, and simplified debugging, helping make front-end development a delightful experience. Semantic is responsively designed allowing your website to scale on multiple devices. Semantic is production ready and partnered with frameworks such as React, Angular, Meteor, and Ember, which means you can integrate it with any of these frameworks to organize your UI layer alongside your application logic.
http://www.semantic-ui.com
https://github.com/Semantic-Org/Semantic-UI