Impossible to add pseudo element to canvases?

Question

So, I\'m currently developing a map editor for a HTML5 game, and while doing so, I wanted to add some pseudo elements to canvases containing thumbnails for building blocks.

Answer 1

Replaced elements (such as canvas and img) do not currently work with pseudo-elements.

Note. This specification does not fully define the interaction of :before and :after with replaced elements (such as IMG in HTML). This will be defined in more detail in a future specification.

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