code:  https://drive.google.com/open?id=1yh4IOWx9YUVxVXfyFdNOIFhje_YXOGe1
demo : https://tieuphongoccho.000webhostapp.com 
demo 2: https://codepen.io/himalayasingh/full/QZKqOX, function(){
// chờ tí cho nó load nhạc nha ☺
}