CSS - add two rules to cover UI elements in really small spaces
Summary:
Fixes T7762.
...so feel free to reject immediately or otherwise tell me where / how these rules should live :D
Test Plan: Used Chrome and Firefox to test display on narrowest as possible widths. Looks better!
Reviewers: epriestley, chad
Reviewed By: chad
Subscribers: chad
Maniphest Tasks: T7762
Differential Revision: https://secure.phabricator.com/D12303