Before diving into Long answer ๐ฉโ๐ซ, let see why stylesheet's size is one of the most important factors in term of web experience.
In general, a stylesheet is just bunch of rules/selectors which can be defined in:
- External files.
- Style tags.
- Inline style attributes.
โ๏ธ There are a lot of discussions for pros and cons of each approach and it's beyond the scope of this article, but if you are interested in you can read here.