I am writing a book with bookdown. Unfortunately, I have no clue how to format (e.g. setting font size) ATX-hearder (#, ##, ## etc.). So far, it does not work via pandoc
or preamble.tex
.
I have tried the following, with regard to this.
Unfortunately, there is an error message :
\usepackage{titlesec} \titleformat{\chapter}[display] {\normalfont\sffamily\huge\bfseries\color{blue}} {\chaptertitlename\ \thechapter}{20pt}{\Huge}
Thanks in advance!