Operation System: Windows 10
Beaker version: Version: 0.8.0-prerelease.7 Electron: 2.0.5 - Chromium: 61.0.3163.100 - Node: 8.9.3

When the window is maximised on Windows, there is a small space between the top of the tabs and the top of the screen. This makes it awkward to select the tabs since you need to accurately move the mouse to make sure you hit the tab to avoid moving "above" the tabs - in most other tabbed browsers the tabs extend to the very top of the screen so that you cannot "overrun" the tab area with the mouse.

This appears to be the culprit:

There seems to be a fullscreen class for what I guess is Mac fullscreen use - if there was a similar class for maximised then you'd not need the resize border space?

E.g. somewhere here you could do something similar for the 'maximize' and 'unmaximize' (sic) events as has already been done for the fullscreen: