要使用CSS在border-bottom-left-radius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: 500px;
height: 400px;
background: yellow;
border: 10px solid green;
border-bottom-left-radius: 150px;
animation: myanim 3s infinite;
background-position: bottom left;
background-size: 50px;
}
@keyframes myanim {
20% {
background-size: 90px;
border-bottom-left-radius: 50px;
}
}
</style>
</head>
<body>
<h2>Performing Animation for bottom border left radius</h2>
<div></div>
</body>
</html>