Responsive css for the media modal

[azaozz]

The current goal is to make the new media modal work/look well on tablets and small-screen laptops (same as the rest of the admin).

In 22615-2.patch:

• At 900px width reduces the width of the left and right areas and reorders the image options so labels ate above the fields.
• 600px is the min-width. The modal has position: absolute so it can be scrolled horizontally.
• Includes couple of fixes for 22615.patch

Good start.

Concur. Commit, mark as see, bump to low priority.

...things that begin with "dev".

In 22887:

Responsive CSS for the media modal. props azaozz. see #22615, #21390.

22615.3.patch​ improves the media selection in the toolbar.

attachment:22615.4.diff​ builds off of​​ attachment:22615.3.patch​:

Needs RTL after the current patch on #22453 is committed.

• Tweaks media selection improvements, moves them to the earlier break point.
• Adjusts modal size, dashed line position, separator size, padding on sidebar, and menu size.

attachment:22615.5.diff​​ adds a lot of RTL stuff. And refreshes 22615.4.diff​. And looks good.

(Except that the search form isn't bumped quickly enough.)

22615.5.diff looks good. The only thing I've noticed is the rounded search field in iOS, but that's the same as other search fields in the admin.

In 22960:

Responsive and RTL css improvements or the media modal.

Props ocean90, koopersmith
see #22615

This ticket is basically just open for any additional cleanups or adjustments we want to make; it's a rider.

If ocean90 or azaozz has anything else here, please re-open. Thanks.