Bug 532185: [Dark Theme] Help content does not respect styling

When the help content is displayed in the external browser the system
preferences about system wide dark or light appearance should be
respected.

There's a CSS standard coming for this: the prefers-color-scheme
media query (see
https://drafts.csswg.org/mediaqueries-5/#prefers-color-scheme ).

The CSS of the help content should incorporate this media
query.

Change-Id: I7090ff35d34c24cdf029fd6210a1b517ba23c465
Signed-off-by: Matthias Becker <ma.becker@sap.com>
diff --git a/platform/org.eclipse.platform/book.css b/platform/org.eclipse.platform/book.css
index 3407d4d..f669f51 100644
--- a/platform/org.eclipse.platform/book.css
+++ b/platform/org.eclipse.platform/book.css
@@ -107,7 +107,29 @@
 				   border-left-color: #7B68EE; padding-left:5 }
 th	     { font-weight: bold }
 
-
 .related {
 	color: #747474;
-}
\ No newline at end of file
+}
+
+@media (prefers-color-scheme: dark) {
+	body { 
+		color:      #f0f0f0; 
+		background: #3d3d3d;
+	} 
+	body, h1, h2, h3, h4, h5, h6, caption, p, 
+	table, td,  th, ul, ol, dl, li, dd, dt{
+		color: #f0f0f0;
+	}
+	
+	a:visited{
+		color: #75d7ff;
+	}
+	
+	a:link{
+		color: #3ac6ff;
+	}
+	
+	a:hover{
+		color: #f0f0f0;
+	}
+}
diff --git a/platform/org.eclipse.platform/macosx_narrow_book.css b/platform/org.eclipse.platform/macosx_narrow_book.css
index 344e5e4..cf531f0 100644
--- a/platform/org.eclipse.platform/macosx_narrow_book.css
+++ b/platform/org.eclipse.platform/macosx_narrow_book.css
@@ -1 +1,7 @@
-h1,h2           { color: Black }
\ No newline at end of file
+h1,h2           { color: Black }
+
+@media (prefers-color-scheme: dark) {
+	h1, h2{
+		color: #f0f0f0;
+	}
+}
\ No newline at end of file
diff --git a/platform/org.eclipse.platform/narrow_book.css b/platform/org.eclipse.platform/narrow_book.css
index c34bb90..81e9527 100644
--- a/platform/org.eclipse.platform/narrow_book.css
+++ b/platform/org.eclipse.platform/narrow_book.css
@@ -117,3 +117,26 @@
 div.revision { border-left-style: solid; border-left-width: thin; 
 				   border-left-color: #7B68EE; padding-left:5 }
 th	     { font-weight: bold }
+
+@media (prefers-color-scheme: dark) {
+	body { 
+		color:      #f0f0f0; 
+		background: #3d3d3d;
+	} 
+	body, h1, h2, h3, h4, h5, h6, caption, p, 
+	table, td,  th, ul, ol, dl, li, dd, dt{
+		color: #f0f0f0;
+	}
+	
+	a:visited{
+		color: #75d7ff;
+	}
+	
+	a:link{
+		color: #3ac6ff;
+	}
+	
+	a:hover{
+		color: #f0f0f0;
+	}
+}
diff --git a/platform/org.eclipse.sdk/book.css b/platform/org.eclipse.sdk/book.css
index 4e3b4a5..3433562 100644
--- a/platform/org.eclipse.sdk/book.css
+++ b/platform/org.eclipse.sdk/book.css
@@ -117,4 +117,28 @@
 
 .related {
 	color: #747474;
+}
+
+@media (prefers-color-scheme: dark) {
+	body { 
+		color:      #f0f0f0; 
+		background: #3d3d3d;
+	} 
+	body, h1, h2, h3, h4, h5, h6, caption, p, 
+	table, td,  th, ul, ol, dl, li, dd, dt{
+		color: #f0f0f0;
+	}
+	
+	a:visited{
+		color: #75d7ff;
+	}
+	
+	a:link{
+		color: #3ac6ff;
+	}
+	
+	a:hover{
+		color: #f0f0f0;
+	}
+
 }
\ No newline at end of file
diff --git a/platform/org.eclipse.sdk/macosx_narrow_book.css b/platform/org.eclipse.sdk/macosx_narrow_book.css
index 344e5e4..cf531f0 100644
--- a/platform/org.eclipse.sdk/macosx_narrow_book.css
+++ b/platform/org.eclipse.sdk/macosx_narrow_book.css
@@ -1 +1,7 @@
-h1,h2           { color: Black }
\ No newline at end of file
+h1,h2           { color: Black }
+
+@media (prefers-color-scheme: dark) {
+	h1, h2{
+		color: #f0f0f0;
+	}
+}
\ No newline at end of file
diff --git a/platform/org.eclipse.sdk/narrow_book.css b/platform/org.eclipse.sdk/narrow_book.css
index c34bb90..4e9181f 100644
--- a/platform/org.eclipse.sdk/narrow_book.css
+++ b/platform/org.eclipse.sdk/narrow_book.css
@@ -117,3 +117,27 @@
 div.revision { border-left-style: solid; border-left-width: thin; 
 				   border-left-color: #7B68EE; padding-left:5 }
 th	     { font-weight: bold }
+
+@media (prefers-color-scheme: dark) {
+	body { 
+		color:      #f0f0f0; 
+		background: #3d3d3d;
+	} 
+	body, h1, h2, h3, h4, h5, h6, caption, p, 
+	table, td,  th, ul, ol, dl, li, dd, dt{
+		color: #f0f0f0;
+	}
+	
+	a:visited{
+		color: #75d7ff;
+	}
+	
+	a:link{
+		color: #3ac6ff;
+	}
+	
+	a:hover{
+		color: #f0f0f0;
+	}
+
+}