Settings Dropdown Styling Issues

[rajadain]

There are some styling issues with the Settings / Sign Out dropdown:

On IE11, there is a white line on the left edge of the dropdown that shouldn't be there.

On Firefox, the top of the dropdown appears to be a different color than that of the dropdown button. This may be because of a leaky shadow.

On Chrome on macOS, the dropdown button has rounded edges, which look odd:

and on Chrome on Windows there is a dark blue border on the bottom edge of the button:

Safari also has the leaky shadow effect, as well as an icon misplacement in the search bar:

The search bar doesn't look any better expanded on Safari: