WordPress no longer supports many old old browsers: https://make.wordpress.org/core/2017/04/23/target-browser-coverage/
This also removes alot of no longer necessary CSS. It served us well, but we are never getting back together with IE8,9,10.
So, in the (paraphrased) words of Taylor Swift:
I remember when we dropped support the first time
Saying, "This is it, I've had enough, " 'cause like
We hadn't seen many users in a month
When you said you needed flexbox. (What?)
Then you postMessage again and say
"IE8, I miss you and I swear I'm gonna change, trust me."
Remember how that lasted for a day?
I say, "I hate the box model, " we break up, you call me, "I love css-grids."
Ooh, we called it off again last night
But ooh, this time I'm telling you, I'm telling you
We are never ever ever supporting IE 8,9,10,
We are never ever ever supporting IE 8,9,10,
You go talk to EDGE, talk to my FIREFOX, talk to CHROME
But we are never ever ever ever getting back together
Like, ever...
Fixes#37651.
Props stunnedbeast, netweb, jorbin.
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git-svn-id: http://core.svn.wordpress.org/trunk@40912 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Currently, the "Collapse menu" item is not focusable and keyboard users can't collapse/expand the admin menu. This aims to fix it so that screen readers no longer announce it as a clickable but it remains unfocusable and thus unusable. So it's now a button.
Quoting joedolson at WordCamp Chicago 2014:
"If it's supposed to act like a button, it should be a button."
Also includes a grunt:precommit run that picked up some postcss changes to src/wp-includes/css/customize-preview.css
Fixes#29958.
Props ajercia, ipm-frommen for an iterative patch, valendesigns for an iterative patch, GaryJ for feedback, joedolson for feedback, helen for feedback
Built from https://develop.svn.wordpress.org/trunk@39141
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Aaron Jorbin
Jeremy Felt
Andrea Fercia
Dion Hulse