Seeds
Sprout's Exquisitely Executed Design System
Typography
Sizes are based on a perfect fourth modular scale. Line heights are proportional, calculated to ensure that least every third line of type alignes to an 8px grid. If you’re curious about the math, check out (this CodePen)[http://codepen.io/team/Sprout/pen/33052a068736d398dc0702d7146231a3].
Speaking of that CodePen—currently, seeds-typography only implements the large scale, but future explorations will determine if the other scales provide value.