Content entrance was a scale+overshoot pop; mara didn't like it on
review, swapped for a plain fade. The nav underline now hops through
every nav item it passes over on its way to the new active one
(position and colour together) instead of tweening directly between
the two endpoints, matching what she actually meant by "move through
color wheel" — a->c visibly touches b's colour along the way, not a
smooth continuous hue rotation.
a5584d0fcd