How has Facebook built this fixed-on-scroll box with iOS support? [closed]

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Closed 9 years ago.

How has Facebook built this fixed-on-scroll box (sticky sidebar) on their new prasentation site for the new newsfeed?

I know many of the solutions for doing this but this one is special. The switching between position: relative and position: fixed works at the touchmove event (not special) but it also works on the iOS scroll pan!

I thought that wasn't possible - see here. How did they do this?

Answer 1

Apparantly it uses the webkit function position: -webkit-sticky;

Explanation is found here.