Add basic style changes for screens larger than 600 pixles
Add responsive images demo
Add fluid grid demo
Modify demo styles for mobile first
Add additional media query styles for adaptive layout
Implement an adaptive navigation menu
Add background style to feature section and navigation
Fix cross browser issue in firefox, CSS3 property background-size: cover
Tweak feature background to extend to the full width of the screen
Change title to placeholder text
Refactor styles