Google does crawl "the way you see it" and not via raw html parsing. They interpret JavaScript and CSS.
Try putting display:none on a div with some text in it, or putting the font-size to 1px. It will not rank for that and you will probably trigger a penalty of some sort if it's egregious.
Invisible or near invisible text can be discerned without rendering the page.
Google does execute JavaScript but as best people can tell it doesn't happen all the time, just periodically. It would be computationally expensive to do this for every request on every spider view for every web site.
I'm not saying they don't do it - everyone knows they do. I'm saying for many, many cases there's no reason for them to do it for every page and every site.
Try putting display:none on a div with some text in it, or putting the font-size to 1px. It will not rank for that and you will probably trigger a penalty of some sort if it's egregious.