[Tex/LaTex] tcolorbox: How to create layout of single box on one side, multiple boxes on other

adjustboxtcolorboxvertical alignment

I have three tcolorboxes where I would like the layout to be similar to this:

enter image description here

I can make the titles of the first and second box align using the adjustbox package (as seen here), but I'm unsure how I would make the third box be positioned underneath the second box.

Current best efforts give this:

enter image description here

Code:

\documentclass{article}
\usepackage{tikz, adjustbox}
\usepackage[most]{tcolorbox}

\begin{document}

\begin{centering}
\tcbset{colback=blue!5!white,colframe=blue!75!black,fonttitle=\bfseries, width = 6cm}
\begin{tcolorbox}[title = First box,before=\adjustbox{valign=t}\bgroup, after=\egroup]
\begin{itemize}
\item A
\item B
\item C
\item D
\item E
\end{itemize}
\end{tcolorbox}
\tcbset{colback=red!5!white,colframe=red!75!black,fonttitle=\bfseries, width = 5cm}
\begin{tcolorbox}[title = Second box,before=\adjustbox{valign=t}\bgroup, after=\egroup]
\begin{itemize}
\item F
\end{itemize}
\end{tcolorbox}
\tcbset{colback=green!5!white,colframe=green!75!black,fonttitle=\bfseries, width = 5cm}
\begin{tcolorbox}[title = Third box]
\begin{itemize}
\item G
\item H
\item I
\item J
\end{itemize}
\end{tcolorbox}

\end{centering}

\end{document}

Best Answer

Here is an attempt with rasters. Not fully automatic as you have to specify the heights and the second and third boxed are engulfed in to a separate tcolobox. There is scope for improvement but this should serve as a starting point.

\documentclass{article}
\usepackage[most]{tcolorbox}

\begin{document}

\begin{tcbraster}[raster equal height,raster valign=top,raster columns=2, raster rows=1,
colframe=red!50!black,colback=red!10!white,colbacktitle=red!50!white,
]
\begin{tcolorbox}[title = First box,colback=blue!5!white,colframe=blue!75!black,fonttitle=\bfseries,height=8.05cm, width = 6cm]
\begin{itemize}
\item A
\item B
\item C
\item D
\item E
\end{itemize}
\end{tcolorbox}
\begin{tcolorbox}[boxsep=0pt,boxrule=0pt,colback=white,enhanced jigsaw,left=0mm,right=0mm,top=0mm,bottom=0mm]
\begin{tcolorbox}[title = Second box,colback=red!5!white,colframe=red!75!black,fonttitle=\bfseries,height=2cm, width = 5cm]
\begin{itemize}
\item F
\end{itemize}
\end{tcolorbox}
\begin{tcolorbox}[title = Third box,colback=green!5!white,colframe=green!75!black,fonttitle=\bfseries, height=6cm, width = 5cm,before=\par\vspace{-0.2\baselineskip}]
\begin{itemize}
\item G
\item H
\item I
\item J
\end{itemize}
\end{tcolorbox}
\end{tcolorbox}

\end{tcbraster}

\end{document}

enter image description here

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