When we analyze the visual anatomy of today's most popular apps, we can observe a very high degree of consistency, making them feel polished, easy to navigate, and generally pleasant to interact with. Besides the consistent use of typography and color, we might find that the same paddings are applied to cards, forms, and menus, that the proportions of modules are affected similarly by viewport changes, and that animations all follow the same set of rules. To ensure the correct application of patterns and attributes defined by an underlying design language, digital product teams use standardized component libraries for their design work. Typically, these libraries contain modular building blocks, plus all relevant guidelines specifying nesting and recombination options. Increasingly, these libraries are referred to as UI Kits and are maintained in modern design tools such as Figma, Adobe XD, or Sketch.