JS判断不同操作系统显示不同样式css

 <script type="text/javascript">
         var system ={};
         var p = navigator.platform;             //判断是否为PC
         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){

         }
         else{
             function addNewStyle(news) {
             var styleElement = document.getElementById('p1');

             if (!styleElement) {
                 styleElement = document.createElement('style');0
                 styleElement.type = 'text/css';
                 styleElement.id = 'createElement';
                 document.getElementsByTagName('head')[0].appendChild(styleElement);
             }
             styleElement.appendChild(document.createTextNode(news));
         }
         addNewStyle('.logos{display:none;}')   //新添加的样式
         addNewStyle('.twom{display:none;}')
          }
         </script>