1.代码：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>超大背景图片</title>
<style>
body{
background-image: url(images/bg.jpg);
/* 背景不重复 */
background-repeat: no-repeat;
/* 水平居中，垂直靠上 */
background-position: center top;
}
</style>
</head>
<body>
</body>
</html>2.运行效果：
