Move the overridden CSS to overrides.css which can be applied on nixos.org

doc/Makefile

@@ -23,6 +23,7 @@ out/html/index.html: manual-full.xml style.css
 		"$$XSL/docbook/xhtml/docbook.xsl" \
 		./manual-full.xml
 
+	cp ./overrides.css out/html/
 	cp ./style.css out/html/style.css
 
 	mkdir -p out/html/images/callouts
@@ -36,6 +37,7 @@ out/epub/manual.epub: manual-full.xml
 		"$$XSL/docbook/epub/docbook.xsl" \
 		./manual-full.xml
 
+	cp ./overrides.css out/epub/scratch/OEBPS
 	cp ./style.css out/epub/scratch/OEBPS
 	mkdir -p out/epub/scratch/OEBPS/images/callouts/
 	cp "$$XSL/docbook/images/callouts/"*.svg out/epub/scratch/OEBPS/images/callouts/

doc/default.nix

@@ -16,7 +16,7 @@ pkgs.stdenv.mkDerivation {
   xsltFlags = lib.concatStringsSep " " [
     "--param section.autolabel 1"
     "--param section.label.includes.component.label 1"
-    "--stringparam html.stylesheet 'style.css'"
+    "--stringparam html.stylesheet 'style.css overrides.css'"
     "--param xref.with.number.and.title 1"
     "--param toc.section.depth 3"
     "--stringparam admon.style ''"

doc/overrides.css

@@ -0,0 +1,8 @@
+
+.programlisting img {
+    width: 1em;
+}
+
+.calloutlist img {
+    width: 1.5em;
+}

doc/style.css

@@ -118,15 +118,6 @@ div.example pre.programlisting
     margin: 0 0 0 0;
 }
 
-.programlisting img {
-    width: 1em;
-}
-
-
-.calloutlist img {
-    width: 1.5em;
-}
-
 /***************************************************************************
                                Notes, warnings etc:
  ***************************************************************************/