</div>
请参考：
<!DOCTYPE html><html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style type="text/css">
/*画整个圆*/
.round1{
position: absolute
top: -50px
width: 100px
height: 100px
background-color: pink
border-radius: 50%
}
.mask2{
position: relative
width: 100px
height: 100px
overflow: hidden
}
.round2{
position: absolute
top: 50px
width: 100px
height: 100px
background-color: cornflowerblue
border-radius: 50px
}
</style>
</head>
<body>
<div class="round1"></div>
<div class="mask2">
<div class="round2"></div>
</div>
</body>
</html>
