R1:e04eeea7a52f

Revert changeset css changes

Summary: I changed some CSS here that was not intended.

Test Plan: Reload a few Diffs, no bottom padding at last diff now.

Reviewers: epriestley, btrahan

CC: Korvin, epriestley, aran

Differential Revision: https://secure.phabricator.com/D7433