<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>css3radius</title>
<style>
.radius {
height: 200px;
200px;
background-color: pink;
/*前缀写法在标准写法后面，且值不一样，就会出现问题*/
border-radius: 50px;
-webkit-border-radius: 50px;
}
</style>
</head>
<body>
<div class="radius">你好 我是html5</div>
</body>
</html>