Line numbers are off-center when viewing file sources in blob viewer on Safari

example here (tested in Safari 12.1.2):
https://gitlab.com/gitlab-org/gitlab/blob/master/app/assets/stylesheets/framework/dropdowns.scss#L596-603

Screen_Shot_2019-10-03_at_1.11.30_PM

is this line 594 or 595??

I've seen this regression happen several times in the last few years, and I'm not sure how we can stop this regression from continuing to happen.