"Reply to" popup on post after time gap is misaligned

[FichteFoll]

For clarification, I am specifically referring to the stripes and the content reaching over the normal page bounds on the right side.

This should probably involve a rework of how these sub-posts are inserted, so that the following (from this related topic) is also fixed:

@FichteFoll

I think that upward expansion needs to be fixed in a sense that it looks like downward does currently, i.e. it should be inserted in a way that makes:

1. The wide line appear above the in-reply-to and post rows
2. The narrow line appear between the in-reply-to and post rows
3. No double lines anywhere.