Better Screen Border When Burrito has Focus

[AsherGlick]

Currently there is a red border that appears when Burrito takes control over the entire screen. This functionally works but can be upgraded to be a more visually interesting, as well as be more indicative that the mouse and keyboard are being captured by burrito.

Guild Wars 2 has a specific special effect around the screen in certain situations, maybe mimicking something like that while making it visually distinct from the in-game effect is a good idea.