mdframed的圆角选项无效
\documentclass[zihao=-4]{ctexart}
\usepackage{xcolor}
\usepackage{mdframed}
\definecolor{bg}{HTML}{f3f5f6}
\mdfsetup{%
topline = false, rightline = false,
leftline = false, bottomline = false,
backgroundcolor=bg,roundcorner=5pt}
\usepackage{zhlipsum}
\begin{document}
\begin{mdframed}
\zhlipsum{1}
\end{mdframed}
\end{document}