Change 843485 had a related patch set uploaded (by Matthias Mullie; author: Matthias Mullie):

[mediawiki/core@master] Make search results page widths more consistent

https://gerrit.wikimedia.org/r/843485

Above patch will ensure search results always take up 50em, regardless of whether an interwiki widget is present.
Except, however, in the case that an interwiki widget is present, but the window is not wide enough to show 50em search results + 30% interwiki widget (e.g. on tablets)
In that case, the search results will be allowed to shrink in size - up until the tablet breakpoint (at which point the search results width is roughly equivalent to 25em in old-vector), at which point the interwiki results are no longer displayed & the search results occupy all available space again.

I also fixed a couple of other inconsistencies:

• the interwiki widget was not properly right-aligned (there was 2% whitespace between it and the right hand side; merely because that positioning solution needed some extra safety space)
• there was 8% of whitespace between the results and the interwiki widget. I've narrowed that to 5%. Along with the removal of the 2% on the other side of the interwiki widget, the main search results now have 5% more room in cases where the screen isn't big enough to display the results at 50em.
  • note: at 5% between the results and the widget, that still leaves us with 33px whitespace separating them in the smallest screen width that still allows showing both.

Here's what that all looks like:

	old vector	new vector
narrowest possible
wide

@Sneha Ok if I update the ticket description/AC in this ticket to match what we discussed in T320577?

Sounds good