要使用CSS设置插入边框，请使用带有值插入的border-style属性。
<html> <head> </head> <body> <p style = "border-width:4px; border-style:none;"> This is a border with none width. </p> <p style = "border-width:4px; border-style:inset;"> This is inset border. </p> </body> </html>