Fortitude was architected around one simple principle: provide developers with a consistent API to compose views without having to dive into the CSS
Good vertical rhythm guides the user's gaze comfortably through your content by ensuring consistent, predictable vertical spacing between all elements. Everything in Fortitude respects a base vertical unit of size.
block__element--modifier syntax keeps you out of the documentation and in the markup. Classes in Fortitude follow consistent conventions.
Fortitude classes apply the styles you want without inheritence. Writing new functionality is a breeze, since you won't have to work around edge cases in your current stylesheets.
Fortitude allows you to think in visual styles - it's all right there on the surface. Build your site's design on top, any way you want.
With a small amount of learning, everyone on your team will have magical front-end powers