Small issue: the shadow between the top and the scrollable area with the toggles and code fades out when you scroll down (presumably it should be initially hidden and fade in).

Good catch! It's not a fading-in issue; the shadow is just scrolling out of view. I designed those "overhang" box-shadows to be applied to the inside of an element rather than cast down from one. I see now that I need to apply the latter kind in this case. Thanks for letting me know!