Link to your html file in side tag https://teamx.infuze.lk/scroll.css
<head>
<title>GitHub Example HTML File</title>
<link rel="shortcut icon" href="images/logo.png" type="image/x-icon">
<link rel="stylesheet" href="css/main.css" />
<link rel="stylesheet" href="https://teamx.infuze.lk/scroll.css ">
</head>
Or you can download and edit...