abstract：<!DOCTYPE html><html><head> <title>标题</title> <style type="text/css"> div{width: 100px;height: 100px;border: 1px solid blue;border-radius: 10px;box-shado
<!DOCTYPE html>
<html>
<head>
<title>标题</title>
<style type="text/css">
div{width: 100px;height: 100px;border: 1px solid blue;border-radius: 10px;box-shadow: 10px 5px 4px #CCC}
</style>
</head>
<body>
<div></div>
</body>
</html>
Correcting teacher：天蓬老师Correction time：2019-06-03 09:32:33
Teacher's summary：边框是css盒模型最有意义的属性, 不像内外边距, 只支持宽度