要使用CSS在text-decoration属性上实现动画，您可以尝试运行以下代码-
<!DOCTYPE html>
<html>
<head>
<style>
#demo {
position: absolute;
right: 0;
width: 300px;
height: 200px;
background-color: blue;
text-decoration: underline;
animation: myanim 3s infinite;
}
@keyframes myanim {
30% {
right: 350px;
text-decoration-color: orange;
}
}
</style>
</head>
<body>
<h1>CSS text-decoration-color property</h1>
<div id = "demo">
<h1>This is demo text.</h1>
</div>
</body>
</html>