Added responsive at 599px

+ combined some selector rulesets
+ many `@media (max-width: 599px)` rules fixes #64 ([test bookmarklet](https://f.cloud.github.com/assets/3332524/2429339/59edcb30-ac7b-11e3-9353-8251b87272eb.jpg))
+ should look good down to 320px wide (iPhone 3gx & other older smart phones)
+ might still have [credits wrapping](https://f.cloud.github.com/assets/3332524/2429339/59edcb30-ac7b-11e3-9353-8251b87272eb.jpg)