html - what does Ctrl + PLUS/MINUS do in modern browsers? -

from understanding, best way increasing text size using ctrl + +. keeps layout. know browsers when key combination pressed? want make sure layout isn't

i've seen many websites (even google , amazon) have problems zooming, divs start overlay each other , text gets messy. visible on websites not have fixed width body.

edit: want know happens: how elements , divs no fixed width handled? html div width change to? elements change in same proportion etc... think there clear specification since browsers seem show similar results when zooming in , out.

ctrl + + zooms browser in, while ctrl + - zooms browser out.

documentation