Use the :before element to insert some content before any element.
Example
You can try to run the following code to insert some content before an element with CSS −
<html>
<head>
<style>
p:before {
content: url(/images/bullet.gif)
}
</style>
</head>
<body>
<p> This line will be preceded by a bullet.</p>
<p> This line will be preceded by a bullet.</p>
<p> This line will be preceded by a bullet.</p>
</body>
</html>