Pseudo-Element Compatibility for ::before and ::after

In HTML5, ::before and ::after pseudo-elements can enhance elements with additional content, such as icons or checkmarks. However, not all elements fully support these pseudo-elements.

Input Elements and ::after

In the example provided, the ::after pseudo-element is not displaying on input elements. This is because input elements, similar to img and br, do not have document tree content. According to the CSS2.1 specification (http://www.w3.org/TR/CSS21/generate.html), ::after only works on elements that have such content.

Therefore, input elements cannot generate content using ::after. Alternative methods, such as using background images or custom elements, can be utilized to achieve similar effects on input fields.

It's important to consider element-specific compatibility when utilizing pseudo-elements. The full list of supported elements for ::before and ::after can be found in the CSS specification. By understanding the limitations and capabilities of pseudo-elements, developers can effectively apply them to enhance user interfaces without encountering unexpected behavior.