CSS is a bad example of this, it's not like typical language code because you could have bits of css in many different files that all affect a single element.

CSS is a bad example of this, it's not like typical language code because you could have bits of css in many different files that all affect a single element. CSS is kind of like a language where mixins, monkey-patching, & aspect oriented programming are used to the extreme. Everyone who codes in this language would never go back to the main source function to modify behavior; they would instead write an aspect to patch it. Eventually nobody would know where the "main" code is anymore, all the code would be peppered in different files stomping on each other's toes. Essentially, you could be a great developer and you could still output low quality css simply due to the way css was designed.