The pseudo-classes and pseudo-elements are keywords that can be appended to selectors to make them more specific. They are easy to recognize because they are always preceded by one or two colons.
Pseudo-Elements
Pseudo-elements enable parts of an element to be styled. Only one of these can be applied to any one selector.
first-letter and first-line
The pseudo-elements ::first-letter and ::first-line
can apply styles to the first letter and the first line of an element. They work only on block elements such as paragraphs.
p::first-letter { font-size: 120%; }
p::first-line { font-weight: bold; ...
