"Back to top" with keyboard

[ghost]

Hi,

If you go to http://a11y-guidelines.orange.com/ and scroll with the down key, the "back to top" widget appears (text +arrow).
If you scroll back to the top of the page, the arrow disappears but not the text bubble.

Please fix 😉

@Lausselloic who do we assign this to, by the way?

[ghost]

Bug reproduced with Firefox DevEd, Internet Explorer 11, Vivaldi.

[ghost]

Note: the Boosted widget works correctly http://boosted.orange.com/v4-alpha/boostwatch/

[ffoodd]

Happening when scrolling down with the mouse, too :)