CSS Styling the "close" link. How?

Question

css

Hi all! tell me - somewhere I saw a good article on how to stick buttons correctly - <div>but I couldn't find something, share it.
In the meantime, I haven’t found it - I had to do it myself - I need to get a button like this:
I kind of did something similar, but I don’t have enough knowledge yet - I want to read about it in more detail, I just remember that it was described in the article how to properly glue it to the parent element and etc.
Here's what I got:
jsfiddle.net/2nt74tck/5
A couple of questions - why doesn't javascript work there (when you click on the cross) - in the example that I posted, although I have such an implementation in my project and everything works. The question is why?
And the second question is it works correctly in a wrapper<tr><td>in view of the fact that the child element is not correctly pulled to the corners - therefore, please share a link to the material where you can read about it.
Thanks in advance.

Answer 1

here is an example of a close button
jsfiddle.net/soledar10/heb785oy