Sandbox

<script> (function() {

   // Only run on Sandbox page
   if (mw.config.get('wgPageName') === 'Sandbox') {

       // Detect Mac desktop
       var platform = navigator.platform.toLowerCase();
       if (platform.indexOf('mac') !== -1) {

           // Show an alert
           alert("Hello World – Mac desktop detected!");

           // Add a visible message on the page
           var msg = document.createElement('div');
           msg.textContent = "Hello World – Mac desktop detected!";
           msg.style.color = 'red';
           msg.style.fontWeight = 'bold';
           msg.style.fontSize = '16px';
           msg.style.margin = '10px 0';
           document.body.prepend(msg);

       }
   }

})(); </script>