Update style.css

Removed outline: 0; from the reset and removed the outline: 0; from the :focus reset also, as it's vital to keyboard navigation and has been shown people don't style it back after the reset.
https://github.com/stubbornella/csslint/wiki/Disallow-outline%3Anone
Merge pull request #1 from JakeChampion/master

Removed outline reset as it's bad for accessibility