You can easily add a non-scrolling top row - or footer row - to your website.  The UltimateWB website has a non-scrolling top row.  We use it to allow users to login/access their account easily, and also to make the menu always available at the top for easy access.  Keyword "Easy" 

How to create your non-scrolling top row?  

On your website Admin Panel, go to List Page > Add Page. 

Here, choose the Content Type "Top Row" for creating a non scrolling top row, of "Footer Row", for a footer row....told you it is easy!

Choose a Label for this page, so that you can easily find it later in your Pages List to update as needed.  And use the Content section of this page to enter any content you want on this page.  

To place your menu here, you can copy/paste the Placeholder Text from the Configure Site > Styles Manager page, Menu section.  There, also make sure you choose the Menu position "Custom Horizontal, Top Row".

For placing a Login form here, copy/paste the Placeholder Text from the Configure Site > Social Networking page.

Each of your current pages should by default be affected by adding a Top Row section, unless you have marked on the Add/Edit page for it to not use a Top Row:

To make the Top Row - or Footer Row - look like how you want, in terms of styling and sizing, just go to the Top Row / Footer Row sections in the Styles Manager to customize!  If you have turned the Responsive App ON in the Styles Manager, you can also choose in that section to merge the top row and/or footer row with the rest of the page at smaller window sizes.