网站禁止PC电脑访问，只允许手机访问代码

限制网页只在手机端中打开，网站屏蔽PC端访问JS代码，网站只允许手机端访问

<script type="text/javascript">  if(window.screen.width==0){window.location.replace("https://xxxx.com")};  var system={win:false,mac:false,xll:false};  var p = navigator.platform;  system.win=p.indexOf("Win")==0;  system.mac=p.indexOf("Mac")==0;  system.x11=(p=="X11") || (p.indexOf("Linux")==0);  if(system.win||system.mac||system.xll) {  location.replace("https://xxxx.com");  }  </script>