User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_3) AppleWebKit/600.6.3 (KHTML, like Gecko) Version/8.0.6 Safari/600.6.3
Steps to reproduce:
1. Visit http://keithclark.co.uk/temp/pure-css-parallax-nav-demo/
2. Click 'Slide 4', page should smooth scroll to slide 4
2. Click 'Slide 2', page should smooth scroll to slide 2
3. Click browser Back, page should smooth scroll to slide 4
4. Click browser Forward, page should smooth scroll to slide 2
Using the back/forward buttons does not trigger a scroll in this example
Page should have smooth scrolled to slides 4 and 2
I have reproduced this using these instructions. IMHO, this is a bug - users would expect the scrolling to be consistent when using the back/forward buttons to navigate between different hash URI's of the same page.
Thanks for the report! I can reproduce on OS X nightly.
This doesn't seem to be limited to `scroll-behavior: smooth`: if I remove that, the page still doesn't scroll on back/forward.
Any chance you could minimize the testcase even further, removing everything not required to reproduce the bug?
I've reduced the test case further: http://codepen.io/keithclark/pen/mJoxbo
It seems the problem occurs when an anchor is nested inside an element with the overflow property set.
In the demo above, comment out the `overflow` properties on lines 4 and 10 of the CSS to see the desired result.
Thanks for the testcase! Looks like this is a known bug...
*** This bug has been marked as a duplicate of bug 391664 ***