Hello, I'm new with greensock and rails. I found this demo http://codepen.io/GreenSock/pen/yhEmn very fascinating so I want to add it to my project. Then Firstly, I added the .html.erb file.  Then added css to .scss file  Then added js to .js file  added gem to gemfile  added require require/Tweenmax to js require tree  But the web page did't show any animation  Can anybody know how to figure it out? Thanks a lot.