I have correctly included the bootstrap navbar fix code. However, when I scroll the screen, my sections overflow the navbar. The navbar is not fixed at the top of the page. Should I make changes in the bootstrap.min.css file or modify the HTML code?
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0, shrink-to-fit=no">
<title>RaLas</title>
<link rel="stylesheet" href="...">
</head>
<body>
<!-- Start: Navigation Clean -->
<nav class="navbar navbar-light navbar-expand-md navbar-inverse navbar-fixed-top navigation-clean sticky-top">
<div class="container"><button data-toggle="collapse" class="navbar-toggler" data-target="#navcol-1"><span class="sr-only">Toggle navigation</span><span class="navbar-toggler-icon"></span></button>
...
<!-- End: social media Icons -->
</div>
</header>
</section>
<script src="...min.js"></script>
...
</script>
</body>
</html>