Call the function (end animation mobile navigation disappeared effect) when the transition is completed events.
<!doctype html> <html> <head> <meta charset="utf-8"> <style> #d1 { width:600px; height:600px; margin:100px auto; border:1px solid; } #d2 { width:300px; height:300px; margin:150px; border-radius: 150px; background: #ccc; transition-duration: 2s; } </style> </head> <body> <div id="d1"> <div id="d2"></div> </div> <script> var d1 = document.getElementById("d1"); var d2 = document.getElementById("d2"); d1.onclick = function(){ d2.style.width = "150px"; d2.style.height = "150px"; d2.style.borderRadius = "75px"; d2.style.background = "green"; }; d2.addEventListener("transitionend",function(){ d2.style.display = "none"; }) </script> </body> </html>