Bulma

Bulma is a free, open source, and modern CSS framework based on Flexbox. Bulma provides ready-to-use frontend components that can be easily combined to build responsive web interfaces.

The website offers features such as Dark Mode, Smart Grid, CSS Variables, Auto-Color, Themes, Skeleton Loaders, Auto-Palettes, Dart Sass Support, Improved Accessibility, HSLA, and more.