These styles have drifted away from the HTML structure since they were
written in 2017.
General:
* Add some comments
* Replace complicated selectors with simple class selectors
styles.less:
* Hide section edit links (previously we relied on MobileFrontend
styles, which one handled some cases - removing them in I9a88b80c2a)
* Show print footer, hide Minerva footer
header.less:
* Remove FIXME (resolved in c323c6858a).
* Fix hiding the search box. In 0bee6a1eb6 a <form> for the search box
was added to the header, and these styles (using tag selectors) were
not updated. Use class selectors instead.
* Remove styles for <h1>. The element was changed to <a> in
a905b1c161, styles to override font-size etc. are no longer needed.
* Consolidate 'padding' rules and remove unneeded !important.
article.less:
* Replace the `[ class|='mw-content' ]` selector, which was not
matching anything. It would match elements with `class="mw-content"`
or `class="mw-content-…"`, but the node we're trying to style has
`class="mw-body-content mw-content-ltr"` (since 7cda5b0bf8 in
MediaWiki core). Use a class selector instead.
* Replace the `.mw-body > .content` selector too. While this one
works, it is also needlessly complicated.
footer.less:
* Fix and simplify how last-modified info and license text is unhidden
(while other parts of the footer remain hidden).
* Remove styles for .license. Unused since 1f2b7dff15, use the desktop
footer added in that commit instead.
* Use the desktop footer for last-modified info, since it's more
suitable for "archiving" (it has a date rather than time ago).
Bug: T323636
Change-Id: I21ef26355e3e6dd8b0c34ae933b7f5b0b222655c