Firefox Mobile 1.0rc1 on N800. Steps to reproduce: 1) Load http://krijnhoetmer.nl/irc-logs/whatwg/20100106 2) Press the "zoom in" hardware button a couple of times. Actual results: The content canvas and the CSS view port are both zoomed such that the CSS view port becomes wider than the screen but the flow of the content doesn't change relative to the CSS view port. Expected results: Expected the kind of zooming that happens on desktop Firefox: Expected the width of the CSS view port to continue to match the screen width in deviced pixels but expected the coordinate system of content canvas to be zoomed so that content would be reflowed to narrower view port in terms of CSS pixels. Additional info: The current zooming behavior on mobile makes sense for rigid layouts but not for fluid layouts. Therefore, the "expected results" above are only expected if the layout is detected to be fluid, where a layout is fluid if zooming per "expected results" doesn't cause the content canvas to grow wider in CSS px than the view port in CSS px.