CSS :after not adding content to certain elements
I'm having trouble understanding the behavior of the CSS :after property. According to the spec (here and here):
As their names indicate, the :before and :after pseudo-elements specify the location of content before and after an element's document tree content.
This doesn't seem to place restrictions on which elements can have a :after (or :before) property. However, it seems to only work with specific elements... <p> works, <img> doesn't, <input> doesn't, <table> does. I'm could test more, but the point is made. Note that this seems pretty consistent across browsers. What determines whether an object can accept a :before and :after property?
img and input are both replaced elements.
A replaced element is any element whose appearance and dimensions are defined by an external resource. Examples include images ( tags), plugins (