How to add a custom small window to the page_html/css_WEB-ITnose

As shown in the picture:
The effect to be achieved: anything that can be added in the large window (pictures, text, etc.) can be added to the small window; when the small window is displayed, the large window behind it has a layer of blur. version (just like in the picture, you can highlight the small window), and then click anywhere outside the small window to automatically disappear
Please give me a small example. It would be better if there is a little text explanation, even if there is I would also be very grateful if a master can share his ideas
By the way, I am Xiaobai, I can only say that I can understand javascript, but I have never seen jquery, so if you have any jquery stuff. . . uh

Reply to discussion (solution)

You can modify the css style according to your own requirementsClick here to open the window