Fixed media querries for IE8

We need default values that don't rely on media querries to support
IE8. Override them at the end screen size-specific values.
Merge in media querries fix for IE8
Add mobile styles for #responseBox

On mobile #responseBox was showing up off screen
Style tweaks - flatten

Removed box-shadow and border radius on .answers and #next and removed
box-shadow on #response
Lowercase answer choice to match others