答案1
\documentclass{article}
\usepackage[skins]{tcolorbox}
\usetikzlibrary{shadows,shadows.blur}
\begin{document}
\begin{tcolorbox}[enhanced,width=5in,%center upper,
drop fuzzy shadow={shadow xshift=\boxShadowOfset, shadow yshift=-1.2\boxShadowOfset, shadow blur steps=6,fill=cyan},
boxrule=4pt,sharp corners,colframe=cyan,colback=white!10]
dddd
dddd
\end{tcolorbox}
\end{document}