Sticky Nav
There are two options for the header : static and sticky to the top page.
The default state is static.
Static means as you scroll down the site, so does the navigation. Sticky means as you scroll down the page, the navigation stays fixed in place, so that it is always displaying, no matter where you are on the page.
Add a .mn--sticky class to the #root to make it sticky to its current position.
<body>
<div id="root" class="root mn--sticky">
...
</div>
</body>