From 263eb74afee76ef6df67e7c693d5fcd301baf83e Mon Sep 17 00:00:00 2001
From: Cedric <ced@sdf.org>
Date: Mon, 20 Jan 2025 20:47:59 +0000
Subject: [PATCH] Fix the chemical equation.

All credits due to @michal-h21
https://github.com/michal-h21/tex4ebook/issues/137
---
 book/tex4ebook.cfg | 14 ++++++++++++++
 book/website.cfg   | 12 ++++++++++++
 2 files changed, 26 insertions(+)

diff --git a/book/tex4ebook.cfg b/book/tex4ebook.cfg
index dffea80..35066f6 100644
--- a/book/tex4ebook.cfg
+++ b/book/tex4ebook.cfg
@@ -19,4 +19,18 @@
     font-family: 'Open Sans';
   }
 </style>}}
+
+% Deal with chemical equations in a single svg
+\ExplSyntaxOn
+\def\standaloneenv#1{}
+\pend:def\schemestart{\Picture+{}}
+\append:def\CF_schemestop{\EndPicture}
+\ExplSyntaxOff
+\makeatletter
+\def\texfourht@tikz@begin{
+  \protect\csname nested:math\endcsname% support display math
+  \Picture+[\csname a:Picture-alt\endcsname]{}%
+}
+\makeatother
+
 \EndPreamble
diff --git a/book/website.cfg b/book/website.cfg
index f236b6e..b87e680 100644
--- a/book/website.cfg
+++ b/book/website.cfg
@@ -47,5 +47,17 @@
 }
 \ConfigureToc{loc}{\HCode{<span class="lofToc">}}{\ }{}{\HCode{</span><br />}}
 
+\ExplSyntaxOn
+\def\standaloneenv#1{}
+\pend:def\schemestart{\Picture+{}}
+\append:def\CF_schemestop{\EndPicture}
+\ExplSyntaxOff
+\makeatletter
+\def\texfourht@tikz@begin{
+  \protect\csname nested:math\endcsname% support display math
+  \Picture+[\csname a:Picture-alt\endcsname]{}%
+}
+\makeatother
+
 \begin{document}
 \EndPreamble