Scroll to ID (one page) section behind floating menu

Can anyone advise how to fix a little problem I am having. I have created a one page site and set different sections as ID's to link from the menu, however when I click on say the "about" link in the menu it shows the text from the about us - but the actual heading for that section is underneath the floating menu at the top.

How do i fix this so that the section heading appears below the floating menu?