Update app.js

javascript/app.js

@@ -343,6 +343,7 @@ customElements.define('midi-visualizer', MidiVisualizer);
         divInner.style.height = "20px";
         divInner.style.lineHeight = "20px";
         divInner.style.paddingRight = "8px"
+        divInner.style.width = "0%";
         divProgress.appendChild(divInner);
         parentProgressbar.insertBefore(divProgress, progressbarContainer);
     }