Clean up some CSS.

Fix the color of the login/out link.
Also get a useful display of the alerts in portrait mode on a Nexus 5.

BUG=skia:

Review URL: https://codereview.chromium.org/735463002
This allows us to cache the oauth credentials for talking to Google Storage.

BUG=skia:2930

Review URL: https://codereview.chromium.org/725203005