first-of-type (:first-of-type)

The :first-of-type CSS pseudo-class represents the first sibling of its type in the list of children of its parent element.

<!DOCTYPE html>
<html>
    <head>
        <style>
            p:first-of-type {
                background: #ff0000;
            }
        </style>
    </head>
    <body>
        <h1>first of type example</h1>
        <p>The first paragraph.</p>
        <p>The second paragraph.</p>
        <p>The third paragraph.</p>
        <p>The fourth paragraph.</p>
    </body>
</html>