javascript - Pop-up box implementation principle

Question

As shown in the picture, what is the implementation principle of clicking a button to pop up a custom box? Ask for guidance!

Answer 1

<p style="position:absolute; top:0px; left:0px"></p>
Just set the position to absolute
It will appear on the page differently according to the top and left you set. Location

Answer 2

Modal box? Principle: Create a p

that is separated from the document flow

Answer 3

One implementation method is to use css positioning to create a p that is separated from the normal document flow, use javascript to achieve interaction and control styles, and use ajax to achieve data acquisition and transmission.
http://www.w3school.com.cn/cs...