Fix various problems with print styles

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

resources/skins.minerva.base.styles/print/article.less

@@ -30,8 +30,7 @@
 	}
 }
 
-// Prefer class & direct child selector `.mw-body > .content` over `#bodyContent`.
+.content {
-.mw-body > .content {
 	padding-top: 55px;
 	position: relative;
 
@@ -60,9 +59,8 @@
 	}
 }
 
-// Prefer class & direct child selector `.mw-body > .content` over `#bodyContent`.
 .thumb:after,
-.mw-body > .content:before {
+.content:before {
 	position: absolute;
 	left: 0;
 	content: '';
@@ -79,9 +77,7 @@
 	font-size: 28px;
 }
 
-// `#mw-content-text` doesn't feature universal class selector.
+.mw-body-content {
-// `class|='mw-content'` catches `.mw-content`, but also `.mw-content-rtl`.
-[ class|='mw-content' ] {
 	font-size: 36px;
 
 	a {

resources/skins.minerva.base.styles/print/footer.less

@@ -8,48 +8,40 @@
 }
 
 // stylelint-disable selector-max-id
-#mw-mf-page-center > footer {
+.minerva-footer {
 	border-top: solid 4px #000;
+	// Un-hide the last-modified info and license text
+	display: block;
 	padding-top: 23px;
 	background: #fff !important;
 
-	.mw-ui-icon:before {
+	.footer-content {
-		display: none !important;
+		display: block !important;
-	}
 
-	.last-modified-bar {
+		#footer-info,
-		background: none !important;
+		#footer-info-lastmod,
-		border: 0 !important;
+		#footer-info-copyright {
-	}
+			display: block !important;
-
-	.last-modifier-tagline {
-		font-size: 36px;
-		padding-top: 0 !important;
-		padding-bottom: 16px !important;
-	}
-
-	.last-modified-bar,
-	.last-modified-bar a {
-		font-weight: bold !important;
-		color: #000 !important;
-	}
-
-	.post-content {
-		margin-top: 15px !important;
-		display: block;
-
-		// ... and add these instead.
-		.hlist,
-		h2 {
-			display: none;
-		}
-
-		.license a,
-		.license {
 			font-size: 30px;
 			color: @colorPrintSubtle;
 			font-weight: normal;
 		}
+
+		.minerva-footer-logo {
+			margin: 0 !important;
+			border: 0 !important;
+			padding: 0 !important;
+		}
+
+		// Hide everything else once again
+		#mw-data-after-content,
+		#footer-places {
+			display: none;
+		}
+	}
+
+	.last-modified-bar {
+		display: none;
 	}
 }
 // stylelint-enable selector-max-id

resources/skins.minerva.base.styles/print/header.less

@@ -1,4 +1,3 @@
-// FIXME: Ensure resources/skins.minerva.base.styles/print.less is removed when promoting
 .header-container,
 .header-container.header-chrome {
 	background: @background-color-base;
@@ -7,42 +6,26 @@
 
 .minerva-header {
 	border-top: 0;
+	// Un-hide the wordmark logo
 	display: block;
 	height: auto;
 	padding: 0 @contentPadding;
 
+	// Hide everything else once again
+	.navigation-drawer,
+	.minerva-search-form,
+	.minerva-user-navigation {
+		display: none !important;
+	}
+
 	.branding-box {
-		padding-left: 0 !important;
+		height: auto;
+		display: block !important;
+		padding: 0 0 51px 0;
 
 		// Beta indication is hidden in print mode
 		sup {
 			display: none !important;
 		}
 	}
-
-	> nav,
-	> div {
-		display: none !important;
-	}
-
-	> .branding-box {
-		height: auto;
-		display: block !important;
-		padding: 0 0 51px 50px;
-
-		h1 {
-			font-size: inherit;
-
-			> * {
-				float: none;
-			}
-
-			// assumes SVG...
-			img {
-				height: 41px;
-				width: auto;
-				vertical-align: inherit;
-			}
-		}
-	}
 }

resources/skins.minerva.base.styles/print/styles.less

@@ -2,15 +2,22 @@
 @import '../../../minerva.less/minerva.mixins.less';
 
 @media print {
+	.mw-editsection,
 	.noprint,
 	.banner-container,
 	.minerva-header,
+	.minerva-footer,
 	.minerva__tab-container,
 	.page-actions-menu,
 	.post-content {
 		display: none;
 	}
 
+	.printfooter {
+		display: block;
+		padding-top: 1em;
+	}
+
 	h1,
 	h2,
 	h3,