Better align restore revision buttons on mobile devices

[yogeshbhutkar]

On mobile devices, the restore revision buttons in the revision comparison view appear too cramped, and they appear misaligned in normal view.

Additionally, due to the fixed height of their parent containers, these buttons shrink significantly when the available space is 330px or less, such as when comparing revisions of different versions. If the screen width decreases any further than 330px, the buttons can become unusable or disappear entirely.

[yogeshbhutkar]

Here, when the width becomes 330px, the button completely shrinks and becomes unusable.

Trac ticket: https://core.trac.wordpress.org/ticket/63029

## Screenshots

Before	After

[joedolson]

The design change is good! I'm wondering if we could also increase the width of the slider in this mobile view? I'm not sure it's helpful to have the significant side padding.

I'd only wrap that into this patch if it's fairly easy to accomplish; if there are problems, that could be a separate ticket.

It would be very difficult to figure out when this was introduced; I'm going to set it as 3.8, the last major admin redesign.

[yogeshbhutkar]

Thanks for the feedback, @joedolson! The slider expands with multiple revisions, but its max width is still capped at 70%:
​https://github.com/WordPress/wordpress-develop/blob/3861c9092e38b43769818810b4ca36d380acbf47/src/wp-admin/css/revisions.css#L167-L168

With 30 revisions, the 70% max-width feels reasonable. Also, increasing it further could cause the tooltip to overflow.

The PR is now ready to be reviewed.

[yogeshbhutkar]

reference for 30 revisions with 70% max-width

[yogeshbhutkar]

I believe the slider behavior could be improved further. Notably, it doesn't support sliding on mobile devices, instead, it acts as a button where ticks must be tapped to move it. I confirmed this on a real device as well.

That said, it's best to address this separately in a dedicated ticket.

Here's a screencast after the latest changes:

​https://github.com/user-attachments/assets/f6ee92e5-2a1f-4db4-af21-14e56d26af92

P.S. This has been tested locally.