I've been poking at this a bit. Not too happy with any of the solutions so far :-/

Where's the patch for this?

https://gerrit.wikimedia.org/r/#/c/219989/
Sorry can't tag it right now as on mobile device and gerrit is not mobile friendly

Change 219989 had a related patch set uploaded (by Phuedx):
Fix the positioning of overlay headings

https://gerrit.wikimedia.org/r/219989

Talk looks fine to me in stable and beta - the close icon and content are aligned:

@bmansurov was concerned about a style regression but I honestly can't see it and am not sure we should block on it:
http://i.imgur.com/90zzOzW.png => http://i.imgur.com/dnVcnlI.png

It's not only a minor styling issue, it's also about doing the right thing. You're basically ignoring "maxwidth - 2*paddings" and displaying content differently.

To quote @Jdlrobson yourself:

When focusing search or editor, the close icon should match up with the content area and the hamburger icon. [1]

You've written this patch to fix the spacing issue, but ignoring the new spacing issue.

[1] https://gerrit.wikimedia.org/r/#/c/219989/

Change 221090 had a related patch set uploaded (by Bmansurov):
Remove wikitext editor padding in alpha and beta.

https://gerrit.wikimedia.org/r/221090

Change 221090 merged by jenkins-bot:
Fix the positioning of overlay headings and content

https://gerrit.wikimedia.org/r/221090

Change 219989 abandoned by Jdlrobson:
Fix the positioning of overlay headings

https://gerrit.wikimedia.org/r/219989