DOM：让一个元素跟随鼠标移动而移动
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<style>
#a {
width: 200px;
height: 30px;
border: 1px solid #000;
text-align: center;
list-style: none;
background-color: pink;
}
#b {
width: 200px;
height: 230px;
border: 1px solid #000;
text-align: center;
list-style: none;
background-color: pink;
}
#ula {
position: absolute;
}
</style>
</head>
<body>
<ul id="ula">
<li id="a">目录</li>
<li id="b">内容</li>
</ul>
<!-- <div id="ula"></div> -->
<script>
var ula = document.querySelector("#ula")
document.addEventListener("mousemove", function (e) {
var x = e.pageX
var y = e.pageY
ula.style.left = x - 130 + "px";
ula.style.top = y - 130 + "px";
})
</script>
</body>
</html>