Pressed some combo -- and...

[097115]

...And got different colored half-transparent squares all around the current webpage. Sounds familiar, maybe? :)

What is it, some function I never used before? Thanks :)

[097115]

Ha, it happened again! Accidentally pressed something -- and got this:

Any ideas what could it be? @brookhong? :)

Thanks :)

[brookhong]

Please see regional hints mode

[097115]

Thanks! And sorry I missed it :)