Reports: Support dark mode (#4198)

chrome/skin/default/zotero/report/detail.css

@@ -1,5 +1,8 @@
 body {
-	background: white;
+	color-scheme: light dark;
+	/* These should be the defaults, but just in case: */
+	background: Canvas;
+	color: CanvasText;
 }
 
 a {

chrome/skin/default/zotero/report/detail_print.css

@@ -2,7 +2,6 @@ body {
 	font: 12pt "Times New Roman", Times, Georgia, serif;
 	margin: 0;
 	width: auto;
-	color: black;
 }
 
 /* Page Breaks (page-break-inside only recognized by Opera) */
@@ -22,6 +21,6 @@ h2 {
 }
 
 a {
-	color: #000;
+	color: inherit;
 	text-decoration: none;
 }

chrome/skin/default/zotero/report/detail_screen.css

@@ -15,7 +15,7 @@ p {
 	line-height: 1.5em;
 }
 
-a:link, a:visited {
+a:any-link {
 	color: #900;
 }
 
@@ -23,6 +23,16 @@ a:hover, a:active {
 	color: #777;
 }
 
+@media (prefers-color-scheme: dark) {
+	a:any-link {
+		color: #f00;
+	}
+
+	a:hover, a:active {
+		color: #999;
+	}
+}
+
 
 ul.report {
 	font-size: 1.4em;