The behaviour of the 'Welcome'-button is inconsistent with the other buttons. When clicking 'Get Started', 'Stay In Touch' or 'Contribute', the content is loaded below the button-bar without refreshing the entire page. On the other hand, when clicking on 'Welcome', the entire page is reloaded.
Steps to reproduce:
# Go to http://www.firebirdtest.com/
# Click on 'Get Started'
Expected: Content below button bar is replaced with 'Get Started' content
Actual: as expected
# Click on 'Welcome'
Expected: Content below button bar is replaced with 'Welcome' content
Actual: Entire page is reloaded
(Note: Clicking on 'Get Started' is optional, behaviour can also be observed when clicking 'Welcome' directly after opening the main page.)