bootstrap sticky top

<div class="position-static">...</div>
<div class="position-relative">...</div>
<div class="position-absolute">...</div>
<div class="position-fixed">...</div>
<div class="position-sticky">...</div>

<nav class="navbar sticky-top navbar-light bg-light">
  <a class="navbar-brand" href="#">Sticky top</a>
</nav>