Hi,=20
This is the model I used to make an eBook of any size. Feel free to modify =
it. Recompile your source codes for eBook is what I would do. Although ther=
e are other forms for ebook format, but LaTeX is fairly good and easy to ge=
nerate an eBook.
For Chinese eBook (horizontal, or vertical), use the well-established skill=
s to modify this code.
If 9pt is desired, use "extsizes" package (google can find it).=20
PS: I don't understand your follow-up question.
\documentclass[10pt]{article} % use extsizes for < 10pt
\usepackage[left=3D0mm,top=3D0mm]{geometry}
\pagestyle{empty}
\setlength{\textheight}{xxmm} % =E5=AD=97=E9=AB=98
\setlength{\textwidth}{xxmm} % =E5=AD=97=E5=AF=AC
\setlength{\paperheight}{xxmm} % =E6=9B=B8=E9=95=B7 (=E8=9E=A2=E5=B9=95=E9=
=95=B7)
\setlength{\paperwidth}{xxmm} % =E6=9B=B8=E5=AF=AC (=E8=9E=A2=E5=B9=95=E5=
=AF=AC)
\parindent=3D2ex
\title{eBook for Readers} \index{\LaTeX!width!paperwidth}
\author{A. Author}
\date{\today}
\begin{document}
\maketitle
This code is for eReaders to read a PDF file.=20
\end{document}