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<html><head><script src="https://ajax.googleapis.com/ajax/libs/jquery/3.7.1/jquery.min.js"></script><script>$(document).ready(function() { $(window).resize(function() { if ($(this).width() < 728) { $("body").css("background-color", "yellow"); } else { $("body").css("background-color", "pink"); } });});</script></head><body><p>Resize the window to change background-color (make the screen's width smaller and larger).</p></body></html>