give \subsection \needspace

layout.sty

@@ -481,6 +481,9 @@ interior code={ \path[tcb fill interior] ([xshift=-2mm]interior.west)
 \titleformat{\section}{\large\needspace{8em}}{\titlebar}{0.1cm}{\textcolor{white}}
 \renewcommand*{\thesection}{\arabic{section}}
 
+\titleformat{\subsection}
+{\needspace{4em}\normalfont\normalsize\bfseries}{\thesubsection}{1em}{}
+
 %
 \titleformat{\subsubsection}
 {\needspace{4em}\normalfont\normalsize\bfseries}{\thesubsubsection}{1em}{}