Of course people zoom in with their browsers, especially older people or those otherwise sight-impaired, but the set of zoomers isn't limited to just them... in

Of course people zoom in with their browsers, especially older people or those otherwise sight-impaired, but the set of zoomers isn't limited to just them... in a universe of an increasing number of very high DPI screens (but where you still can't expect those to be the standard), zooming is pretty commonplace. I zoom myself when a designer decides to use some stupidly small font and then often don't even notice the zoom is on until some other website is using a larger than normal font. So, yes, people do zoom. Does it matter that this breaks your CSS3? I don't know, I'd have to see the breakage to know if it is a showstopper or merely a visual annoyance.