Fade in/out effect for sticky share buttons on blog page

[mmmavis]

Follow-up from PR #3383

Currently we hide sticky buttons on the side when the bottom share buttons are scrolled into the viewport.

From Pomax's comment in the PR

do we want to make the buttons fade out/in rather than abruptly existing, though? It might be jarring to readers to have them suddenly exist or be gone?

@beccaklam thoughts?

[mmmavis]

/cc @Pomax

[beccaklam]

@Pomax @mmmavis I can't see staging anymore but fade in/out sounds good 👍 Thanks for catching that Pomax.

[mmmavis]

hey @beccaklam by "staging" you mean "review app"? Review app is the app that's generated with every PR and self destruct when the PR gets merged 😉

Changes have been pushed to staging (https://foundation.mofostaging.net). Blog example on staging can be found here

[beccaklam]

@mmmavis Oh I see ... thanks :) Just checked it out. I think fading in/out would be a nice transition effect!

[mmmavis]

I'm gonna move this ticket to this sprint 'cuz I've got a PR up for this already 😉