Use linear-gradient() to add angle on linear gradients. You can try to run the following code to implement it to set angles as 0, 90, and -90 degrees
Example
<!DOCTYPE html>
<html>
<head>
<style>
#demo1 {
height: 100px;
background: linear-gradient(0deg, orange, blue);
}
#demo2 {
height: 100px;
background: linear-gradient(90deg, orange, blue);
}
#demo3 {
height: 100px;
background: linear-gradient(-90deg, orange, blue);
}
</style>
</head>
<body>
<h2>Linear Gradients</h2>
<div id = "demo1">0 degree</div><br>
<div id = "demo2">90 degrees</div><br>
<div id = "demo3">-90 degrees</div>
</body>
</html>