Operating elements and positioning elements, using js to implement them is a good choice. There is an example below. Friends who need it can take a look at it.
<!DOCTYPE html> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> <title>One JavaScript instance per day-operate element positioning element</title> <style> div#a{ width:500px; } div{ border:1px solid #000; padding:10px; } #cursor{ position:absolute; background-color:#ff0; width:20px; height:20px; left:50px; top:300px; } </style> <script> function positionObject(obj){ var rect = obj.getBoundingClientRect(); return [rect.left,rect.top]; } window.onload = function(){ var tst = document.documentElement.getBoundingClientRect(); alert(tst.top); var cont = 'A'; var cursor = document.getElementById("cursor"); while(cont){ cont = prompt("where do you want to move the cursor block?","A"); if(cont){ cont = cont.toLowerCase(); if(cont == "a"||cont=="b"||cont=="c"){ var elem = document.getElementById(cont); var pos = positionObject(elem); console.log(pos); cursor.setAttribute("style","top:"+pos[1]+"px;"+"left:"+pos[0]+"px"); } } } } } </script> </head> <body> <div id = "a"> <p>A</p> <div id ="b"> <p>B</p> <div id="c"> <p>C</p> </div> </div> </div> <div id="cursor"> </div> </body> </html>