- [[modularity]] # Idea Instead of having messy code that is all in the same file, web developers separate their code into different files, making each “concern” easier to understand and more convenient when changes must be made. The idea is that your HTML should only contain information about your content, and all of your styling decisions should be made in your CSS. # References - [CSS Utility Classes and "Separation of Concerns"](https://adamwathan.me/css-utility-classes-and-separation-of-concerns/)