W3School TIY
编辑您的代码：
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html> <head> <style type="text/css"> h1:before {content:url("../i/w3school_logo_white.gif"/*tpa=http://www.jb51.net/i/w3school_logo_white.gif*/)} </style> </head> <body> <h1>This is a heading</h1> <p>The :before pseudo-element inserts content before an element.</p> <h1>This is a heading</h1> <p><b>注释：</b>如果已规定 !DOCTYPE，那么 Internet Explorer 8 （以及更高版本）支持 content 属性。 </body> </html>
查看结果: