​x
 
<!DOCTYPE html>
<html>
<head>
<style> 
div
{
border:2px solid;
padding:10px;
background:#dddddd;
border-top-right-radius:2em;
-webkit-border-top-right-radius:2em; /* Safari */
}
</style>
</head>
<body>
​
<div>border-top-right-radius 属性允许您向右上角添加圆角边框。</div>
​
</body>
</html>
​