To set the style of the rule between columns, use the column-rule-style property. You can try to run the following code to implement the column-rule-style property.
Example
<!DOCTYPE html>
<html>
<head>
<style>
.demo {
column-count: 4;
column-gap: 50px;
column-rule-color: maroon;
column-rule-style: dashed;
}
</style>
</head>
<body>
<div class = "demo">
This is demo text. This is demo text. This is demo text. This is demo text.
This is demo text. This is demo text. This is demo text. This is demo text.
This is demo text. This is demo text. This is demo text. This is demo text.
This is demo text. This is demo text. This is demo text. This is demo text.
This is demo text. This is demo text. This is demo text. This is demo text.
This is demo text. This is demo text. This is demo text. This is demo text.
This is demo text. This is demo text. This is demo text. This is demo text.
</div>
</body>
</html>