AI 编程工具<html><head><meta charset="utf-8"> <title>菜鸟教程(runoob.com)</title> <style>body{ background-image: url('smiley.gif');background-repeat: no-repeat;background-attachment:fixed;background-position: 50px 100px;}</style></head><body><p><b>注意：</b>该属性工作在 Firefox 和 Opera, background-attachment 属性会被设置为 "fixed"。</p></body></html>