Create a More Complex Shape Using CSS and HTML

What is a pseudo element?
A CSS pseudo-element is a keyword added to a selector that lets you style a specific part of the selected element(s). For example, ::first-line can be used to change the font of the first line of a paragraph. /* The first line of every "p" element.

::after. In CSS, ::after creates a pseudo-element that is the last child of the selected element. It is often used to add cosmetic content to an element with the content property. It is inline by default.

rotate() The rotate() CSS function defines a transformation that rotates an element around a fixed point on the 2D plane, without deforming it. Its result is a "transform-function" data type.

What is an empty string in CSS? The :empty CSS pseudo-class represents any element that has no children. Children can be either element nodes or text (including whitespace). Comments, processing instructions, and CSS content do not affect whether an element is considered empty.

For more information about the Empty String clink on the link down below:
https://en.wikipedia.org/wiki/Empty_string

The ::before selector inserts something before the content of each selected element(s). Use the content property to specify the content to insert. Use the ::after selector to insert something after the content.