Fixing CSS Editor and HTML Viewer layout in IE11

Loading this up in IE11 I noticed the CSS and HTML windows were on top of each other. Checking the CSS I saw the typo for box-sizing.
Merge pull request #63 from mhbuck/patch-1

CSS typo that fixes CSS Editor and HTML Viewer layout in IE11
Monospace fallback for the editor / code font.
Merge branch 'master' of github.com:flukeout/restaurant