To repeat linear gradients with CSS, use the repeating-linear-gradient() function. You can try to run the following code to implement it:
Example
<!DOCTYPE html>
<html>
<head>
<style>
#demo {
height: 100px;
background: repeating-linear-gradient(red, yellow 30%, green 30%);
}
</style>
</head>
<body>
<h2>Linear Gradient</h2>
<div id = "demo">Repeating Linear Gradients</div><br>
</body>
</html>