菜鸟学堂
在线运行
源代码
<!DOCTYPE html> <html> <head> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta charset="utf-8"> <title>菜鸟学堂(edu.jb51.net)</title> <style> /* For width smaller than 400px: */ body { background-repeat: no-repeat; background-image: url('http://run.jb51.net/uploadfile/2017/0707/20170707045235565.jpg'); } /* For width 400px and larger: */ @media only screen and (min-width: 400px) { body { background-image: url('http://run.jb51.net/uploadfile/2017/0707/20170707045234496.jpg'); } } </style> </head> <body> <p style="margin-top:360px;">调整浏览器宽度，背景图片在小于 400 px 时将改变。</p> </body> </html>
运行结果
在线运行
菜鸟学堂 edu.jb51.net