Referencing nested class does not style in css-CodePudding

I'm trying to reference a nested class within my html, which is under <body>. The issue is, is that if I were to reference body by itself in css, the background would appear. However if I try to reference my class under body, it doesn't appear. I've tried referencing it with a . before the class name which still doesn't work. Code below:

HTML

    <!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">
    <link rel="stylesheet" href="main.css" />
    <title>vxsqi-lib</title>
</head>
<body>
    <div ></div>
</body>
</html>

CSS

.backgroundimage {
    background-image: url("backgroundimage/dark-night-mountains-4k-e3.jpg");
    background-size:cover;
    background-color: white;
}

CodePudding user response：

You can try this,

div.backgroundimage {
background-image: url("backgroundimage/dark-night-mountains-4k-e3.jpg");
background-size:cover;
background-color: white;}

Edit second options because wrong :(

This must be work. Let me know if doesnt