It's very slight, but I just ran through all my SE tabs in Safari refreshing one after the other, as I do a hundred times a day [when I'm bored] & everything on each page just spaced a tiny bit wider.
It's probably not easy to see until you fullscreen this [snaps are from a 27" 1440p screen] but something just changed on every refreshed page. After a few of these I realised I should grab a screen snap of a before & after - you'll have to open each in a new window & flick between to see the effect; it is very slight.
medium images inlined, click to open full size in new window. imgur's 'medium' tag is what puts the bad black 'transparency' around the 'm' pictures in here.