Bulma

Bulma is a free, open-source framework that provides ready-to-use frontend components that you can easily combine to build responsive web interfaces.

It is built by Jeremy Thomas and is fully open source. It provided with an extensive range of built-in features which results in faster turnaround and less CSS code writing.

Bulma is fully responsive. It can be difficult to try to convert a desktop-designed site for use on a mobile device, but with Bulma, it’s not really an issue.

Bulma is a mobile-first CSS framework, offering optimum site responsiveness. Build a site one time and watch it work across any device.