\documentclass{litebook}

\cover{\UPLOWFadingImage[trim={0 {.9\paperheight} 0 0},clip]{cover}
                        [trim={0 {.5\paperheight} 0 0},clip]{cover}}
\title{The \pkg{LiteBook} Template}
\subtitle{Version 0.2b \today}
\author{Hsia Mingyu}
\bioinfo{Hangzhou Dianzi University}
\press{\scshape\textcolor{teal}{\faIcon{telegram-plane}}Hangzhou in Late Spring 2024}

\mdflist{theorem,   lemma,        definition,   proposition,    postulate;
         Theorem,   Lemma,        Definition,   Proposition,    Postulate;
         DarkGreen, MidnightBlue, MidnightBlue, DarkOliveGreen, Indigo}
\amslist{remark,    example,      problem,      solution;
         Remark,    Example,      Problem,      Solution;
         DarkRed,   Teal,         Black,        Black}

\begin{document}

\let\theremark=\relax
\def\theproblem{\arabic{problem}}
\def\theexample{\arabic{example}}
\let\thesolution=\relax

\maketitle
\frontmatter
\tableofcontents
\mainmatter
\input{cha/cha1.tex}
\input{cha/cha2.tex}

\end{document}