If the browser can determine the element you are looking for using just one selector ... inline styles. CSS should go in CSS files. There’s usually a good reason to have multiple stylesheets ...

Here’s a look at the most useful new and upcoming features in CSS this year. The core use case for layers is making it easier to combine multiple ... layers to represent element defaults ...

One of the more important details of understanding and using Cascading Style Sheets (CSS) is the cascading aspect of its name. That is, how are multiple rules for the same element handled?