a.圆角 border-radius:??px b.盒阴影 box-shadow: ?px ?px ?px 颜色;


<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>边框</title>
</head>
<style>
    div {
        width: 300px;
        height: 300px;
        background-color: #7f7f7f;
        border-radius: 30px;/*圆角*/
        box-shadow: 10px 10px 10px yellow;/*阴影*/
    }
</style>
<body>
<div></div>
</body>
</html>