adding transition state for form inputs' placeholder UI
making step__status elements' visual width equal in all cases
cleaning up step__title and step__status UI for responsive layouts
adding visual emphasis to problem's prompt UI
adding graded + required UI back into step__status for peer assessment templates
adding collapse/expand toggle to assessment feedback form UI
aligning step__status icons/text to be left-justified
revising introductory message copy
adding visual spacing between grade report UI sections
finalizing assessment feedback UI
syncing up step__status positioning for larger desktops
Merge pull request #214 from edx/talbs/ui-cleanup

UI Clean Up - Small Tweaks