So this is something that has happened to me multiple times in the past in my chrome browser. For clarity, I use Chrome for work stuff and I do things like this in Firefox, which I prefer. However, where I work is pretty much now a Google shop.
I couldn’t click on any content, anywhere, in any window. I couldn’t even click to change tabs. My browser wasn’t frozen though, I could still type in the Google Doc I had opened on my screen before things went wonky. I could still alt-tab through the opened tabs in a window.