Shows how AngularJS and CSS can play together for form validation. AngularJS port of this jQuery Password strength verification: http://www.webdesignerdepot.com/2012/01/password-strength-verification-with-jquery/
animation(or game) loop with requestAnimationFrame
progress bar with setTimeout will be delayed by heavy process.
one with requestAnimationFrame will be drawn on accurate time course on GoogleChrome. (not good on firefox)