2.7 Summary

circumstances. The ability to group together both selectors and rules keeps style sheets compact and flexible, which incidentally leads to smaller file sizes and faster download times.

it's crucial for authors to correctly write selectors because errors can prevent the user agent from applying the styles as intended. An integral part of correctly understanding selectors and how they can be combined is an understanding of how selectors relate to document structure and how mechanisms—such as inheritance and the cascade itself—come into play when determining how an element is to be styled. This is the subject of the next chapter.