要使用CSS在box-shadow属性上实现动画，您可以尝试运行以下代码
<!DOCTYPE html>
<html>
<head>
<style>
div {
width: 200px;
height: 300px;
background: yellow;
border: 10px solid red;
animation: myanim 3s infinite;
bottom: 30px;
position: absolute;
}
@keyframes myanim {
20% {
bottom: 100px;
box-shadow: 30px 45px 70px orange;
}
}
</style>
</head>
<body>
<h2>Performing Animation on box-shadow</h2>
<div></div>
</body>
</html>