I'm experimenting with some styles on <textarea>s and I tried doing some stuff with ::before and ::after selectors and I couldn't to anything to get them to work. So the question is: is this possible? I know the CSS surrounding forms is arcane beyond mention but it seems like this should work.
The :before and :after will not work on a text-area (nor any element that cannot contain another element, such as img or input), because the generated content of the pseudo-element gets placed within the element but before or after that element's content, and acts itself as an element. The pseudo-element does not get placed before or after the parent element itself (contrary to some information one may find on the internet). To illustrate:
If you have this css:
p:before {content: 'before--'}
p:after {content: '--after'}
Then html like this:
<p>Original Content</p>
Effectively renders to the screen as if the source code were:
<p>before--Original Content--after</p>
Not as if the source code were:
before--<p>Original Content</p>--after
Which is why tags that cannot contain any html element "content" (like those mentioned above) do not recognize the pseudo-elements, as there is no "place" for that content to be generated to. The textarea can contain "content," but only pure text content.