> I guess those sites weren't detecting user agent and were detecting screen resolution? CSS does this via media queries and allows for different layouts witho

> I guess those sites weren't detecting user agent and were detecting screen resolution? CSS does this via media queries and allows for different layouts without sending different content. Switching to a mobile-optimized layout at 1080px (note "px" doesn't mean physical pixels to a mobile browser) seems a bit aggressive though. I imagine it wouldn't be hard for a browser extension to override this behavior, though it could lead to broken layouts or horizontal scrolling.