<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>内边距</title>
</head>
<body>
<div style="width: 500px;margin: 0 auto;border: 10px dotted red">
<div style="border: 2px solid darkmagenta;margin: 0 -50px">
1111111111
</div>
</div>
</body>
</html>
