devbook.xsl, devmanual.css: Add permalinks to section headers

While we use empty fragments ("#") elsewhere for navigation within the
document (because they don't cause reloading of the page), we use an
empty href ("") for the chapter because it is meant to be copied as an
external link.

Closes: https://bugs.gentoo.org/772005
Suggested-by: Sam James <sam@gentoo.org>
Signed-off-by: Ulrich Müller <ulm@gentoo.org>

1 files changed, 14 insertions, 0 deletions

diff --git a/devmanual.css b/devmanual.css
index 288f81d..bba2a31 100644
--- a/devmanual.css
+++ b/devmanual.css
@@ -33,6 +33,20 @@ pre span.Constant { color: black; }
 pre span.Comment { color: red; }
 pre span.Statement { color: darkred; }
 
+a.permalink {
+    padding: 0 0.3em;
+    font-size: 90%;
+    text-decoration: none;
+    visibility: hidden;
+}
+
+h1:hover > a.permalink,
+h2:hover > a.permalink,
+h3:hover > a.permalink,
+h4:hover > a.permalink {
+    visibility: visible;
+}
+
 .truncated-text {
     white-space: nowrap;
     overflow: hidden;