Basic modal scss and example markup in ui.html
0s transition not needed on .content, .overlay. Transition on .active does the trick
Abstracted drawers and modals into _toggles partial
Indentation correction on toggles partial
Added height 100% to body, html to fix % height issue in FF
Revert back to z-index after no go with FF
Remove !important from z-index in failed attempt to fix FF
Modal scss in _toggles.scss w drawers. Example modal markup in ui.html.
Import toggles.scss partial in all.scss
Added close icon markup to modal and updated modal content
Removed overlay and added rbga directly to .modal, updated opacity transitions accordingly. Close icons positioning styles.
Added .center-text class to base.scss, applied to modal content  and added .modal h2 margins directly to ui.html
% min/max heights so modal grows but overflow kicks in when it's too big for viewport
Updated modal explanation text
ui/demo.html updates including IE conditionals fix, script includes and indentation corrections.
tweaks to toggles.scss and some new settings
Increase height to match width for modals at portrait-tablet and all-phones
Modal responsive styles, full screen at portrait tablet
Merge branch 'feature/modal' into develop