The page seems to have the code described here: http://blog.bassta.bg/2013/05/smooth-page-scrolling-with-tweenmax/ http://blog.bassta.bg/2013/05/smooth-page-scr

The page seems to have the code described here: http://blog.bassta.bg/2013/05/smooth-page-scrolling-with-tweenmax/ http://blog.bassta.bg/2013/05/smooth-page-scrolling-with-twe... Basically it disables the browser's default scrolling behavior and handles the mouse scrollwheel events by itself via javascript. Which is usually annoying since the new behavior can be different to what the user is accustomed to, and for other reasons as well. You might find some more arguments in discussions like this: https://www.reddit.com/r/webdev/comments/47n9ph/psa_dont_use_smooth_scroll_scriptsplugins_on_your/ https://www.reddit.com/r/webdev/comments/47n9ph/psa_dont_use...