Bulma is a modern CSS framework based on Flexbox. It aims to be as flexible and lightweight as possible, without sacrificing accessibility. Also it is minimalistic, modular, and flexible enough to use in any project.
This framework is not only for creating responsive layouts but it also has some other use cases. For instance, it can be used to create simple blocks of information or complex navigation tabs. Bulma is modular and comes with a Grid system. It also has prebuilt components and offers easy to use mixins