* Fix inconsistent font size for markdown preview on new PR view (#11565)
We use same method for new issue form and issue view, but was missing from new PR view making it one place where markdown preview is inconsistent in font size.
(cherry picked from commit 04afd9d1e2)
* Fix margin on PR form (#11566)
(cherry picked from commit f2a0be1683)
* Fix margin for attached top header on code review (#11571)
Introduced naively by #11463
The margin was being applied too widely.
(cherry picked from commit e682a92295)
* Fix styling for PR merge section when no checks (#11609)
Makes styling consistent between two cases. Also removed unnecessary double border.
* Normalize avatar radius