diff -r 3d4e9c994f10 -r a86126ab1dd4 wp/wp-admin/css/revisions.css
--- a/wp/wp-admin/css/revisions.css	Tue Oct 22 16:11:46 2019 +0200
+++ b/wp/wp-admin/css/revisions.css	Tue Dec 15 13:49:49 2020 +0100
@@ -79,7 +79,6 @@
 	top: 50%;
 	top: calc( 50% - 10px );
 	transition: opacity 0.5s;
-	filter: alpha(opacity=0); /* ie8 and earlier */
 }
 
 body.folded .revisions .loading-indicator {
@@ -94,7 +93,6 @@
 
 .revisions.loading .loading-indicator {
 	opacity: 1;
-	filter: alpha(opacity=100); /* ie8 and earlier */
 }
 
 .revisions .diff {
@@ -103,7 +101,6 @@
 
 .revisions.loading .diff {
 	opacity: 0.5;
-	filter: alpha(opacity=50); /* ie8 and earlier */
 }
 
 .revisions.diff-error .diff {
@@ -223,8 +220,8 @@
 table.diff th {
 	font-family: Consolas, Monaco, monospace;
 	font-size: 14px;
-	line-height: 1.618;
-	padding: .5em;
+	line-height: 1.57142857;
+	padding: 0.5em 0.5em 0.5em 2em;
 	vertical-align: top;
 	word-wrap: break-word;
 }
@@ -244,6 +241,7 @@
 }
 
 table.diff .diff-deletedline {
+	position: relative;
 	background-color: #ffe9e9;
 }
 
@@ -252,9 +250,26 @@
 }
 
 table.diff .diff-addedline {
+	position: relative;
 	background-color: #e9ffe9;
 }
 
+table.diff .diff-deletedline .dashicons,
+table.diff .diff-addedline .dashicons {
+	position: absolute;
+	top: 0.85714286em;
+	left: 0.5em;
+	width: 1em;
+	height: 1em;
+	font-size: 1em;
+	line-height: 1;
+}
+
+table.diff .diff-addedline .dashicons {
+	/* Compensate the vertically non-centered plus glyph. */
+	top: 0.92857143em;
+}
+
 table.diff .diff-addedline ins {
 	background-color: #afa;
 }
@@ -266,7 +281,7 @@
 }
 
 .diff-title strong {
-	line-height: 32px;
+	line-height: 2.46153846;
 	min-width: 60px;
 	text-align: right;
 	float: left;
@@ -275,7 +290,7 @@
 
 .revisions-controls .author-card .author-info {
 	font-size: 12px;
-	line-height: 16px;
+	line-height: 1.33333333;
 }
 
 .revisions-controls .author-card .avatar,
@@ -367,16 +382,6 @@
 	right: 20px;
 }
 
-.ie8 .revisions-tooltip-arrow > span {
-	left: 15px;
-	top: -25px;
-	-ms-filter: "progid:DXImageTransform.Microsoft.Matrix(SizingMethod='auto expand', M11=0.7071067811865476, M12=-0.7071067811865475, M21=0.7071067811865475, M22=0.7071067811865476)";
-}
-
-.ie8 .revisions-tooltip.flipped .revisions-tooltip-arrow > span {
-	right: 25px;
-}
-
 .revisions-tooltip,
 .revisions-tooltip-arrow > span {
 	border: 1px solid #ddd;
@@ -521,7 +526,7 @@
 
 .wp-slider .ui-slider-range {
 	position: absolute;
-	font-size: .7em;
+	font-size: 0.7em;
 	display: block;
 	border: 0;
 	background-color: transparent;
@@ -529,7 +534,7 @@
 }
 
 .wp-slider.ui-slider-horizontal {
-	height: .7em;
+	height: 0.7em;
 }
 
 .wp-slider.ui-slider-horizontal .ui-slider-handle {