outcome gradebook styles redline

fixes CNVS-10392

test plan:
  * verify that styles match the latest designs

Change-Id: I9a550b0271ac247e5f76ea3813d09132f8994bab
Reviewed-on: https://gerrit.instructure.com/28492
Reviewed-by: Braden Anderson <banderson@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>
QA-Review: Steven Shepherd <sshepherd@instructure.com>
Product-Review: Zach Pendleton <zachp@instructure.com>