Update '12/player.js'

12/player.js

@@ -6,4 +6,7 @@ track.addEventListener('cuechange', function () {
   var d = JSON.parse(cues[0].text);
   console.log("d",d);
   track_div.innerHTML = d.title;
+  var playing = document.getElementById("d.title");
+  playing.classList.add("now_playing");
+  console.log("playing",playing);
 });