Safari will absolutely not quit

[travod]

Quit, force quit, looking for it in activity monitor and killing it there won't quit (it actually does not show up there, nor does it show up if I type top in the terminal). It's like it's not actually open, but it is and I cannot shut down my computer.

What can I do?

 

[Fishrrman]

Hold down the power-on button for at least four seconds.

The computer WILL shut down.

If even that doesn't work, remove the power cord!