I want to fix this menu bar at the top of the page, so that when user scrolls down, the menu bar continues to appear and the content flows into it. I tried everything, some help would be nice. 

Heres the CSS and below the HTML: 

CSS: <https://www.dropbox.com/s/a0z0eov71wvha1c/style.css>

HTML: <https://www.dropbox.com/s/qyvb0oqhx8550ym/html.txt>

Thank you!