<!DOCTYPE html>
<html>
<head lang="en">
<meta charset="UTF-8">
<title></title>
<style>
*{margin: 0;padding: 0;}
body {background-color: black;}
.box {
margin: 100px auto;width: 630px;height: 394px;
border: 2px solid white; background-color: black;
padding: 10px;
}
ul {list-style: none;}
ul li {
float: left; padding: 5px;
}
</style>
</head>
<body>
<div class="box">
<ul>
<li><a href="#"><img src="images/01.jpg"></a></li>
<li><a href="#"><img src="images/02.jpg"></a></li>
<li><a href="#"><img src="images/03.jpg"></a></li>
<li><a href="#"><img src="images/04.jpg"></a></li>
<li><a href="#"><img src="images/05.jpg"></a></li>
<li><a href="#"><img src="images/06.jpg"></a></li>
</ul>
</div>
<script src="https://cdn.bootcss.com/jquery/3.4.1/jquery.js"></script>
<script>
$(function(){
$("li").mouseenter(function(){
$(this).css("opacity","1").siblings().css("opacity","0.4");
});
$("li").mouseleave(function(){
$("li").css("opacity","1");
});
});
</script>
</body>
</html>
原文：https://www.cnblogs.com/sandraryan/p/11072392.html