How to Stop the top menu bar scrolling up page in magento 2 With LUMA Theme (Destop and mobile site

[faraz1990]

How to Stop the top menu bar scrolling up page in magento 2 With LUMA Theme ( Destop Site and Mobile Site Like Following Website http://www.outfitters.com.pk/ 

[Dmitry_Fedyuk]

CSS position: fixed

https://developer.mozilla.org/en/docs/Web/CSS/position