For this, you can use insertRule() with sheet. The code is as follows −
Example
Following is the code −
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<link rel="stylesheet" href="//code.jquery.com/ui/1.12.1/themes/base/jquery-ui.css">
<script src="https://code.jquery.com/jquery-1.12.4.js"></script>
<script src="https://code.jquery.com/ui/1.12.1/jquery-ui.js"></script>
<body>
<div id="demo">
This is a JavaScript program
</div>
</body>
<script>
var creatingStyle = document.createElement("style");
document.head.appendChild(creatingStyle);
creatingStyle.sheet.insertRule(`#demo{
background-color: red;
}`);
</script>
</html>To run the above program, save the file name “anyName.html(index.html)”. Right click on the file and select the option “Open with Live Server” in VSCode editor −
Output
This will produce the following output on console −
