[x] Clicking on a table of contents item doesn't result in that item becoming purple
[x] Ignore the top couple of lines?
[x] Perhaps the last hovered-over panel is the one that should trigger purple highlighting? But what about when we scroll? Replaced with all visible messages (#597)
[x] In the reverse direction, hovering over a table of contents item could highlight the corresponding post on the left, if visible.
Perhaps the last hovered-over panel is the one that should trigger purple highlighting? But what about when we scroll?Replaced with all visible messages (#597)