confirm the bug fixed

elegantbook-cn.tex

@@ -1,4 +1,4 @@
-\documentclass[lang=cn,10pt,founder]{elegantbook}
+\documentclass[lang=cn,10pt]{elegantbook}
 
 \title{ElegantBook：优美的 \LaTeX{} 书籍模板}
 \subtitle{Elegant\LaTeX{} 经典之作}

elegantbook-en.tex

@@ -535,7 +535,8 @@ Note that a subgroup~$H$ of a group $G$ is itself a left coset of $H$ in $G$.
 Let $G$ be a finite group, and let $H$ be a subgroup of $G$. Then the order of $H$ divides the order of $G$.
 \end{theorem}
 
-\ref{thm:lg}
+As theorem \ref{thm:lg} refered.
+
 \lipsum[3]
 
 
@@ -543,6 +544,9 @@ Let $G$ be a finite group, and let $H$ be a subgroup of $G$. Then the order of $
   The content of theorem.
 \end{theorem}
 
+we can refer this theorem as \ref{thm:label text}.
+
+
 \begin{proposition}[Size of Left Coset]
 Let $H$ be a finite subgroup of a group $G$.  Then each left coset of $H$ in $G$ has the same number of elements as $H$.
 \end{proposition}