var isWin = (navigator.userAgent.indexOf("Win") != -1);
var isMac = (navigator.userAgent.indexOf("Mac") != -1);
var isUnix = (navigator.userAgent.indexOf("X11") != -1);
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document.write("");
document.write("body {font-size:" + ((isMac) ? "12" : "10") + "pt}");
document.write("");