<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=gb2312"> <title>无标题文档</title> <style type="text/css"> .m{margin-left:20px;border-left:1px dashed #000;} </style> </head> <body> <div class="m">内容</div> <div class="m">内容</div> <div class="m"> <div class="m">内容</div> <div class="m"> <div class="m">内容</div> </div> </div> </body> </html> [提示：可先修改代码再按运行]
